,,studies ,,on ,,fermentation           
,,studies ,,on ,,fermentation           
,,the ,,diseases ,,of ,,beer            
,,their ,,causes1 ,,and ,,the ,,means   
,,of ,,preventing ,,them                
,,by                                    
,,louis ,,pasteur        ,,member ,,of  
,,institute ,,of ,,france1 ,,the ,,royal
 ,,society ,,of ,,london1 ,,etc4        
,a ,,translation1 ,,made ,,with ,,the   
,,author',s ,,sanction1 ,,of            
8,,tudes ,,sur ,,la ,,bi,,re10 ,,with   
,,notes1 ,,index1 ,,and ,,original      
,,illustrations                         
,,by                                    
,,frank ,,faulkner                      
,,author ,,of 8,,the ,,art ,,of         
,,brewing10 ,,etc4                      
,,and                            ,d4    
,,constable ,,robb1 ,b4,a4              
,,late ,,scholar ,,of ,,worcester       
,,coll41 ,,oxford                       
,london                                 
,,macmillan  ,,co                       
#ahgi          ,,pardon ,,and ,,sons1   

,,printers1 ,,paternoster ,,row1        
,,london4                               
,,to                                    
,,the ,,memory ,,of                     
,,my ,,father1                          
,,formerly ,a ,,soldier ,,under ,,the   
,,first ,,empire1                       
,,and                        ,,knight   
,,of ,,the ,,legion ,,of ,,honour4      
,,the ,,longer ,i ,,live1 ,,the ,,better
 ,,do ,i ,,understand ,,the ,,kindness  
,,of                 ,,thy ,,heart ,,and
 ,,the ,,excellence ,,of ,,thy ,,mind4  
,,to ,,thy ,,example ,,and ,,counsels   
,,do ,i ,,owe ,,the ,,efforts ,,that    
,,have         ,,been ,,devoted ,,to    
,,these ,,studies1 ,,as ,,well ,,as ,,to
 ,,all ,,the ,,work          ,i ,,have  
,,ever ,,done4 ,,and ,,now1 ,,how ,,can 
,i ,,better ,,honour ,,these            
,,filial ,,remembrances ,,than ,,by     
,,dedicating ,,my ,,book ,,to ,,thy     
,,memory8                               
,l4 ,,pasteur4                          
,,author',s ,,preface4      ,our        

misfortunes inspired me with the idea of
 these researches4 ,i  undertook them   
immediately after the war of #ahgj1 and 
have since  continued them without      
interruption1 with the determination of 
perfecting them1 and thereby benefiting 
a branch of industry wherein we  are    
undoubtedly surpassed by ,germany4    ,i
 am convinced that ,i have found a      
precise1 practical solution of the      
arduous problem which ,i proposed to    
myself--that of a process of            
manufacture1 independent of season and  
locality1 which should obviate  the     
necessity of having recourse to the     
costly methods of cooling  employed in  
existing processes1 and at the same time
 secure the  preservation of its        
products for any length of time4        
,these new studies are based on the same
 principles which guided me in my       
researches on wine1 vinegar1 and the    
silkworm disease--principles1 the       
applications of which are practically   
unlimited4 ,the etiology of  contagious 

diseases may1 perhaps1 receive from them
 an unexpected light4    ,i need not    
hazard any prediction concerning the    
advantages likely to  accrue to the     
brewing industry from the adoption of   
such a process of  brewing as my study  
of the subject has enabled me to devise1
 and from an  application of the novel  
facts upon which this process is        
founded4 ,time  is the best appraiser of
 scientific work1 and ,i am not unaware 
that an  industrial discovery rarely    
produces all its fruit in the hands of  
its  first inventor4    ,i began my     
researches at ,clermont-,ferrand1 in the
 laboratory1 and with  the help1 of my  
friend ,m4 ,duclaux1 professor of       
chemistry at the ,faculty  of ,sciences 
of that town4 ,i continued them in      
,paris1 and afterwards at  the great    
brewery of ,tourtel ,brothers1 of       
,tantonville1 which is admitted  to be  
the first in ,france4 ,i heartily thank 
these gentlemen for their  extreme      
kindness4 ,i owe also a public tribute  

of gratitude to ,m4 ,kuhn1 a  clever    
brewer of ,chamalires1 near             
,clermont-,ferrand1 as well as to ,m4   
,velten1 of ,marseilles1 and to ,,mm4 de
 ,tassigny1 of ,reims1 who have placed  
at my disposal their establishments and 
their products1 with the most           
praiseworthy willingness4    ,l4        
,,pasteur4    ,,paris1 ,june #a1 #ahgf4 
,,preface ,,to ,,english ,,edition4     
,my first idea of placing before        
,english brewers a translation of 8tudes
  sur la ,bire0 was meagre in the       
extreme1 compared with the final        
realization of it as it appears in the  
following pages4    ,seeing the vast    
importance of ,pasteur's work from a    
practical point of  view1 after writing 
a review of it for the ,brewers'        
,journal1 ,i  determined to procure1 at 
any rate for the use of my pupils1 a    
literal  translation1 illustrated by    
photo-lithographic copies of the        
original  plates1 the thankless task of 
executing this preliminary translation  

for  so limited a number of readers     
being most kindly and generously carried
  out for me by my friend ,mr4 ,frank   
,u4 ,waite1 who1 being engaged with me  
at the time in practical brewing        
operations1 shared my views as to the   
value of the original work4    ,it was  
on the completion of this translation   
that my views and desires  expanded4    
,the more ,i studied the work1 the more 
,i was convinced of its  immense value  
to the brewer as affording him an       
intelligent knowledge of  the processes 
and materials with which he deals1 but  
over and above all  this1 it was        
impossible not to feel that the         
researches of such a  devoted and       
accomplished savant as ,pasteur1        
possessed a scientific  interest much   
wider than their mere relation to the   
art of brewing would  imply4 ,as the    
work of a skilful chemist and a         
laborious and accurate  observer1 such a
 protracted and careful study of the    
lowest and simplest  forms of life1 must

 necessarily be of first importance to  
the  biologist--to the beginner as an   
admirable introduction to the study of  
practical physiology in general1 as well
 as to the more advanced  student1 from 
the suggestive light which it throws on 
the nature of  analogous phenomena in   
more complex organisms4    ,i determined
 accordingly to publish the work if ,i  
could secure the  consent of its        
distinguished author1 but at the same   
time ,i felt that  the publication of   
,m4 ,pasteur's 8,studies0 in the form in
 which ,mr4 ,waite  had1 at my request1 
translated it1 and illustrated only with
 inferior  copies of the original       
plates1 would not be either advisable or
 just2  but that ,i was bound rather to 
put the book before the ,english public 
in  as satisfactory and complete a form 
as lay within my power4 ,under these    
circumstances ,i was induced to seek the
 aid of ,mr4 ,d4 ,constable ,robb1      
,b4,a41 of ,the ,oxford ,university     
,museum1 who1 in taking ,mr4 ,waite's   

version as a basis1 has so elaborated1  
annotated1 and recast it1 that ,i  feel 
bound to say that much of the value of  
8,studies on ,fermentation10  as it now 
appears1 is due to the care that ,mr4   
,robb has bestowed upon  the revision   
that he so kindly undertook2 a revision 
the result of which  has created a      
feeling of confidence in the success of 
the translation as  it now stands1 which
 ,i could not have had in any mere      
literal version4    ,to the practical   
worker the original illustrations alone1
 which appear  in this version1 cannot  
but be of immense value in the          
microscopical  study of the changes in  
the liquids with which he deals2 whilst 
the many  notes and additions1 which are
 a feature peculiar to the ,english     
edition1 more particularly the rendering
 into the equivalents1 with  which1     
unfortunately1 practical men on this    
side of the channel are  still most at  
home1 of the metric weights and measures
 and centigrade  temperatures1 as well  

as the ,index which ,mr4 ,robb has      
compiled1 will1 ,i  trust1 render the   
book of still greater service than it   
otherwise would  have been to many of   
those who may favour it with their      
attention4    ,the debt which we        
,english brewers owe to ,m4 ,pasteur can
 hardly be  over-estimated1 and ,i must 
be allowed here to express my personal  
obligations to that distinguished worker
 for the permission which allows  this  
translation2 and to the ,french         
publishers for their help with  regard  
to the interleaved illustrations4       
,the author's preface and dedication    
are1 of course1 reproduced1 the  former 
making it unnecessary for me to refer   
more in detail to the  contents of the  
translation4    ,,frank ,,faulkner4     
,,the ,,brewery1 ,,st4 ,,helen',s1      
,,lancashire1  ,september1 #ahgi4       
,,table ,,of ,,contents4                
,,author',s ,,dedication v              
,,author',s ,,preface vii               
,,translator',s ,,preface ix            

,,chapter ,i4    ,,on ,,the ,,intimate  
,,relation ,,existing ,,between ,,the   
,,deterioration ,,of ,,beer1 ,,or  ,,the
 ,,wort ,,from ,,which ,,it ,,is ,,made1
 ,,and ,,the ,,process ,,of ,,brewing #a
      ,,chapter ,,ii4    ,,on ,,the     
,,causes ,,of ,,the ,,diseases ,,which  
,,affect ,,beer ,,and ,,wort4     ,i4   
,every unhealthy change in the quality  
of beer coincides with a  development of
 microscopic germs which are alien to   
the pure ferment of  beer #ai     ,,ii4 
,the absence of change in wort and beer 
coincides with the absence  of foreign  
organisms #be      ,,chapter ,,iii4     
,,on ,,the ,,origin ,,of ,,ferments     
,,properly ,,so ,,called4     ,i4 ,on   
the conditions which cause variations in
 the nature of the  organized products  
existing in infusions #cc     ,,ii4     
,experiments on blood and urine taken in
 their normal state1 and  exposed to    
contact with air that has been deprived 
of the particles of  dust which it      
generally holds in suspension #dj       

,,iii4 ,experiments on the juice        
contained in grapes #ed     ,,iv4 ,wort 
and must exposed to common air #ei      
,v4 ,new comparative studies on the     
germs held in suspension by the air  of 
different places which are near each    
other1 but subjected to  different      
conditions affecting the production and 
diffusion of the  particles of dust     
found in them #gb     ,,vi4 ,yeast may  
become dry and be reduced to dust       
without losing its  faculty of          
reproduction #ha      ,,chapter ,,iv4   
,,the ,,growth ,,of ,,different         
,,organisms ,,in ,a ,,state ,,of        
,,purity3 ,,their ,,autonomy4     ,i4   
,growth of ,penicillium glaucum and     
,aspergillus glaucus in a  state of     
purity4--,proofs that these fungoid     
growths do not become  transformed into 
the alcoholic ferments of beer or       
wine4--,preliminary  inquiry into the   
cause of fermentation #hf     ,,ii4     
,growth of ,mycoderma vini in a state of
 purity4--,confirmation of  our original

 conjectures as to the cause of         
fermentation4--,mycoderma  vini does not
 change into yeast1 although it may give
 rise to  fermentation #ajh     ,,iii4  
,growth of ,mycoderma aceti in a state  
of purity #aba     ,,iv4 ,growth of     
,mucor racemosus in a state of          
purity4--,example of life  more active  
and lasting when removed from the       
influence of air #abg      ,,chapter ,v4
    ,,the ,,alcoholic ,,ferments4       
,i4 ,on the origin of ferment #adc      
,,ii4 ,on 8spontaneous0 ferment #ahb    
,,iii4 ,on 8high0 and 8low0 ferments    
#ahf     ,,iv4 ,on the existence and    
production of other species of ferment  
#aif     ,v4 ,on a new race of alcoholic
 ferments3 ,arobian ferments #bje       
,,vi4 ,the purification of commercial   
yeasts #bai      ,,chapter ,,vi4        
,,the ,,physiological ,,theory ,,of     
,,fermentation4     ,i4 ,on the         
relations existing between oxygen and   
yeast #bce     ,,ii4 ,fermentation in   
saccharine fruits immersed in carbonic  

acid gas  #bff     ,,iii4 ,reply to     
certain critical observations of the    
,german naturalists1  ,oscar ,brefeld   
and ,moritz ,traube #bgi     ,,iv4      
,fermentation of dextro-tartrate of lime
 #bhd     ,v4 ,another example of life  
without air4--,fermentation of lactate  
of  lime #bib     ,,vi4 ,reply to the   
critical observations of ,liebig1       
published in #ahgj  #caf      ,,chapter 
,,vii4    ,,new ,,process ,,for ,,the   
,,manufacture ,,of ,,beer4     ,i4      
,preliminary experiments #cch     ,,ii4 
,method of estimating the oxygen held in
 solution in wort #cec     ,,iii4 ,on   
the quantity of oxygen existing in a    
state of solution in  brewers' worts    
#cfd     ,,iv4 ,on the combination of   
oxygen with wort #cga     ,v4 ,on the   
influence of oxygen in combination on   
the clarification of  wort #cha         
,,vi4 ,application of the principles of 
the new process of brewing with  the use
 of limited quantities of air #chg      
,,appendix #cif    ,,index #djc         

,,index ,,to ,,plates4      ,i4         
,principal disease-ferments met with in 
wort and beer #f    ,,ii4 ,appearance   
under the microscope of the deposit from
 8turned0 beer #bj    ,,iii4 ,torul in  
process of development #gb    ,,iv4     
,mycoderma vini functioning as an       
alcoholic ferment4--,right half1        
showing appearance of spores just sown2 
left half1 their appearance  after an   
interval of submerged life #aaf    ,v4  
,mucor1 vegetating submerged1 in deficit
 of air #acf    ,,vi4 ,ferment of mucor 
#ach    ,,vii4 ,yeast-cells--worn out   
and dissociated 7left71 after revival in
 a  sweet wort 7right7 #adh    ,,viii4  
,fertile mould-cells from the outer     
surface of grapes #aeb    ,,ix4 ,various
 examples of the mode of growth of      
mould-cells from the outer  surface of  
grapes #aed    ,x4 ,one of the ferments 
of acid fruits at the commencement of   
fermentation in its natural medium #aff 
,,xi4 ,saccharomyces pastorianus1 in    
course of regular growth #afh    ,,xii4 

,ferment-cells from a spontaneous       
fermentation just starting #ahd         
,,chapter ,i4  ,on the ,intimate        
,relation existing between the          
,deterioration of ,beer1 or        the  
,wort from which it is ,made1 and the   
,process of ,brewing4      ,at the      
outset of these 8,studies10 let us      
briefly consider the nature of  beer and
 the methods of its manufacture4        
,beer is a beverage which has been known
 from the earliest times4 ,it may  be   
described as an infusion of germinated  
barley and hops1 which has  been caused 
to ferment after having been cooled1 and
 which1 by means of  8settling0 and     
racking1 has ultimately been brought to 
a high state of  clarification4 ,it is  
an alcoholic beverage1 vegetable in its 
origin--a  barley wine1 as it is        
sometimes rightly termed4#a    ,beer and
 wine1 however1 differ widely in their  
composition4 ,beer is less  acid and    
less alcoholic than wine2 it holds more 
ingredients in  solution1 and the nature

 of these ingredients is by no means    
similar to  that of those which are     
found in wine4    ,these differences in 
the component parts of wine and beer    
give rise to  corresponding differences 
in the keeping qualities of the two     
liquids4  ,the small amount of acidity  
in beer1 its poverty in alcohol1 and the
  presence of matter that is saccharine1
 or liable to become so1 all  operate in
 imparting to beer a tendency to change1
 which wine does not  possess4 ,that    
this unequal resistance to the          
aggression of diseases is  due to such  
differences1 may be proved by the fact  
that wine could be  made much more      
liable to change than it actually is1 by
 a diminution of  its acidity and its   
usual proportion of alcohol1 or by      
increasing the  proportion of viscid or 
saccharine matters1#b modifications     
which would  tend to assimilate its     
composition to that of beer4    ,we have
 remarked elsewhere that the pains      
devoted to the rearing of  vines1 and to

 the ordinary operations of             
vinification1 such as  ouillage1#c      
sulphuring1 and repeated rackings1 as   
well as the use of  cellars and vessels 
hermetically closed1 are entailed by the
 necessity  of counteracting and        
preventing the diseases to which wine is
 liable4  ,the same may be said1 a      
fortiori1 of beer1 inasmuch as it is    
more  liable to change than wine4       
,manufacturers and retailers of this    
beverage  have to strive constantly with
 the difficulty of preserving it1 or the
  wort used in its manufacture4 ,we may 
readily be convinced of this by         
reviewing the usual processes of the art
 of brewing4    ,when the infusion of   
malt and hops1 which is termed wort1 is 
completed1  it is left to cool4 ,it is  
next put into one or more casks or vats1
 in  which it is made to undergo        
alcoholic fermentation--the most        
important of  all the processes in      
brewing4    ,the cooling must be as     
rapid as possible4 ,this is a condition 

of  success2 otherwise1 the wort may    
deteriorate1 which will necessarily     
lead to deterioration in the quality of 
the beer4 ,as long as the wort is  at a 
high temperature it will remain sound2  
when under #gj ,c4 7#aeh ,f471  and     
particularly when at a temperature of   
from #be ,c4 to #ce ,c4 7#gg ,f4  to #ie
 ,f71 it will be quickly invaded by     
lactic and butyric ferments4  ,rapidity 
in cooling is so essential that to      
secure it recourse is had to  special   
apparatus4#d ,even in the preparation of
 wort1 especially when  it is effected  
by successive mashings1 in summer1      
deterioration is  imminent3 in fact1 it 
is not rare to see the wort becoming    
acid during  the mashes1 if these are   
not accomplished with all possible      
celerity4    ,after the wort has been   
cooled1 it is mixed with yeast4 ,this is
 obtained  from a previous fermentation1
 and1 after being thoroughly pressed1 is
  added at the rate of from one to two  
thousandth parts of the weight of  the  

wort1 that is1 from #ajj to #bjj grammes
 per hectolitre 7about #d oz4  to #h oz4
 average for every #be gallons74 ,at    
first sight1 this yeast seems  free from
 the possible diseases of the wort and  
beer2 but this is by no  means the case4
    ,now1 why do we add yeast to our    
wort8 ,this practice is unknown in the  
art of vinification4 ,the must is always
 left to spontaneous  fermentation4 ,why
 should we not leave the wort to operate
 in the same  manner8    ,it would be a 
mistake to suppose that in the brewing  
of beer yeast is  added with the sole   
object of accelerating fermentation1 and
 making it  more rapid4 ,rapidity in    
fermentation is a very questionable     
advantage1  and one which is not desired
 by brewers1 who rather agree in        
pronouncing it injurious to the quality 
of beer4 ,it is in the easy             
deterioration of the wort1 or what is   
tantamount to it1 in the  facility it   
affords to various spontaneous          
fermentations1 that we find  an answer  

to these questions4 ,the must1 through  
its acidity1 due to  the presence of    
bitartrate of potash--which seems to    
promote alcoholic  fermentation--through
 its proportion of sugar1 and perhaps in
  consequence of some other peculiarity 
of its composition1 always  undergoes   
regular alcoholic fermentation4 ,the    
diseases of wine1 at the  commencement  
of its manufacture1 show themselves1 so 
to say1 in a  latent state only4        
,therefore a vintage can be left1       
without  inconvenience1 to spontaneous  
fermentation4    ,with wort the case is 
quite different4 ,under certain         
accidental  circumstances it is possible
 that alcoholic fermentation alone may  
take  place in a wort left to ferment   
spontaneously1 and the quality of the   
beer remain unimpaired1 but such an     
event would be exceptional1 and of  very
 rare occurrence4 ,in most cases we     
should obtain an acid or putrid  liquid 
resulting from the production and       
multiplication of alien  ferments4      

,the addition of yeast is made in       
consequence of the necessity of         
exciting through the whole bulk of wort1
 as soon as it is cold1 a single        
fermentation--viz41 the alcoholic1 the  
only one that can produce beer  properly
 so called4    ,the alcoholic ferments  
concerned in the production of beer will
 be found  represented in several of the
 engravings in this work4 ,other        
ferments we  may term 8diseased02 these 
include all those that may occur        
spontaneously--that is1 whose germs have
 not been directly and  intentionally   
introduced--amongst the actual alcoholic
 ferments4    ,the expression1 8diseased
 ferments10 is justified by the         
circumstance  that the propagation of   
these ferments is always accompanied by 
the  production of substances which are 
acid1 putrid1 viscous1 bitter1 or       
otherwise unpalatable1 a consideration  
of commercial rather than  scientific   
importance4 ,from a physiological point 
of view1 all these  ferments are of     

equal interest and importance4 ,the     
botanist1 as a man of  science1 in      
contemplating nature1 must give equal   
attention to all  plants1 whether useful
 or noxious1 since they are all governed
 by the  same natural laws1 among which 
no order of merit could be established4 
,the exigencies of industry and health  
require1 however1 wide  distinctions4   
,illustration3 ,plate #a4 ,principal    
,disease-ferments met with in ,wort and 
,beer4    ,the first engraving 7,plate  
,i47 represents the different diseased  
ferments1 together with some cells of   
alcoholic yeast1 to show the  relative  
size of these organisms4    ,no4 #a of  
the engraving represents the ferments of
 turned beer1 as it  is called4 ,these  
are filaments1 simple or articulated    
into chains of  different size1 and     
having a diameter of about the          
thousandth part of a  millimetre 7about 
#a_/bejjj inch74 ,under a very high     
power they are seen  to be composed of  
many series of shorter filaments1       

immovable in their  articulations1 which
 are scarcely visible4    ,in ,no4 #b   
are given the lactic ferments of wort   
and beer4 ,these are  small1 fine and   
contracted in their middle4 ,they are   
generally detached1  but sometimes occur
 in chains of two or three4 ,their      
diameter is a  little greater than that 
of ,no4 #a4    ,in ,no4 #c are given the
 ferments of putrid wort and beer4      
,these are  mobile filaments whose      
movements are more or less rapid1       
according to  the temperature4 ,their   
diameter varies1 but is for the most    
part greater  than that of the filaments
 of ,nos4 #a and #b4 ,they generally    
appear at the  commencement of          
fermentation1 when it is slow1 and are  
almost invariably  the result of very   
defective working4    ,in ,no4 #d are   
given the ferments of viscous wort1 and 
those of ropy beer1  which the ,french  
call filante4 ,they form chaplets of    
nearly spherical  grains4 ,these        
ferments rarely occur in wort1 and still

 less frequently  in beer4    ,no4 #e   
represents the ferments of pungent1 sour
 beer1 which possesses an  acetic odour4
 ,these ferments occur in the shape of  
chaplets1 and consist  of the mycoderma 
aceti1 which bears a close resemblance  
to lactic  ferments 7,no4 #b71          
especially in the early stages of       
development4 ,their  physiological      
functions are widely different1 in spite
 of this  similarity4    ,the ferments  
given in ,no4 #g characterize beer of a 
peculiar acidity1  which reminds one    
more or less of unripe1 acid fruit1 with
 an odour sui  generis4 ,these ferments 
occur in the form of grains which       
resemble  little spherical points1      
placed two together1 or forming squares4
 ,they  are generally found with the    
filaments of ,no4 #a1 and are more to be
  feared than the latter1 which cause no
 very great deterioration in the        
quality of beer1 when alone4 ,when ,no4 
#g is present1 by itself or with  ,no4  
#a1 the beer acquires a sour taste and  

smell that render it  detestable4 ,we   
have met with this ferment existing in  
beer1  unaccompanied by other ferments1 
and have been convinced of its fatal    
effects4    ,no4 #f represents one of   
the deposits belonging to wort4 ,this   
must not be  confounded with the        
deposits of diseased ferments4 ,the     
latter are always  visibly organized1   
whilst the former is shapeless1 although
 it would not  always be easy to decide 
between the two characters1 if several  
samples  of both descriptions were not  
present4 ,this shapeless deposit        
interferes  with wort during its        
cooling4 ,it is generally absent from   
beer1 because  it remains in the backs1 
or on the coolers2 or it may get        
entangled in  the yeast during          
fermentation and disappear with it4     
,among the shapeless granulations of    
,no4 #f may be discerned little  spheres
 of different sizes and perfect         
regularity4 ,these are balls of         
resinous and colouring matter that are  

frequently found in old beer1 at  the   
bottom of bottles or casks2 sometimes   
they occur in wort preserved  after     
,appert's method4 ,they resemble        
organized products1 but are nothing  of 
the kind4 ,we have remarked before1 in  
8,studies on ,wine10 that the  colouring
 matter of wine would settle1 in course 
of time1 in that form4    ,it is evident
 that the different ferments delineated 
in ,plate ,i4 are  worthy of thorough   
study1 in consequence of the            
fermentations to which  they may give   
rise4 ,care must be taken to isolate the
 action of each of  them in             
fermentations which we may call pure--a 
condition of some  difficulty1 but one  
that may be carried out by an adoption  
of the  methods explained in this work4 
,all these diseased ferments have a     
common origin4 ,their germs1            
infinitesimal and hardly perceptible as 
they are1 even with the aid of  the     
microscope1 form a part of the dust     
conveyed through the air4 ,this  dust   

the air is continually taking from or   
depositing upon all objects  in nature1 
so that the dust that clings to the     
ingredients from which  our beer is     
manufactured1 may teem with the germs of
 diseased ferments4    ,during the      
process of fermentation1 the occult     
power of diseased  ferments1 although it
 may escape the observation of the      
brewer1 is  manifested in a high degree4
    ,during the last thirty years1 or   
so1 the art of brewing has undergone a  
radical change1 at least in ,europe4    
,this change has been effected by a     
partial abandonment of the process of   
fermentation formerly used4 ,thirty     
years ago only one kind of beer was     
known2 there are nowadays two  distinct 
kinds--beer fermented at a high         
temperature1 and beer fermented  at a   
low temperature4 ,each of these is      
subdivided into many varieties1  to     
which different names are given1        
according to their strength or  colour4 
,this is the case in ,england1 where we 

find porter1 ale1 pale  ale1 stout1     
bitter beer1 and other varieties of     
beer1 although1 as a  matter of fact1   
the ,english have but one kind of beer1 
all the ,english  beers being fermented 
at a high temperature4    ,let us       
briefly examine the differences existing
 between the two kinds of  beer4        
,formerly all beer was fermented at a   
high temperature4 ,the wort1 after      
having been cooled in the backs1 was run
 into a large vat1 at a  temperature of 
about #bj ,c4 7#fh ,f474 ,yeast was then
 added to it1 and  when the fermentation
 began to show itself1 in the formation 
of a light1  white froth1 upon the      
surface of the liquid1 the wort was run 
into  casks1 having a capacity of from  
#ej to #ajj litres 7#aa to #bb          
gallons7--#ge  litres being the         
commonest size4 ,these casks were placed
 in cellars1  having a temperature of   
from #ah ,c4 to #bj ,c4 7#fd ,f4 to #fh 
,f474 ,the  activity of fermentation    
soon produced a froth that grew thicker 

and  more and more viscous in proportion
 to the quantity of yeast it  contained4
 ,the yeast worked out of the bung-holes
 and dropped into a  vessel placed under
 the casks2 there it was gathered for   
subsequent  operations4 ,it always      
exceeded the quantity used in the first 
instance1  the ferment increasing       
greatly during the process of           
fermentation4 ,the  increase in its     
weight varied with the weight of yeast  
used and the  composition of the wort4  
,under the ordinary conditions of       
brewing1 where  the weight of the       
pitching yeast was about one thousandth 
part of the  weight of the wort1 the    
increase is said to have been from five 
to seven  times the weight of the yeast2
 but such increase must naturally have  
been determined by the quality of the   
wort1 the quantity of hops used1  the   
action of oxygen1 and the proportion of 
barm employed4 ,the process  of         
fermentation lasted from three to four  
days4 ,by that time the beer  was       

finished1 and had become limpid1 the    
fermentation having been  completed4    
,the bungs could then be placed in the  
casks1 and the beer be  delivered to the
 customer4#e ,a certain amount of yeast 
still remained  in the casks1 and caused
 the beer to become thick1 in transit2  
but a few  days' rest sufficed to       
restore its brilliancy1 and render it   
fit for  drinking or bottling4    ,here 
we have an explanation of the term 8high
 fermentation10 which has  been applied 
to the foregoing process4 ,this process 
is conducted at a  high temperature1    
which1 commencing at #ai ,c4 or #bj ,c4 
7#ff ,f4 or #fh  ,f471 is raised to #bj 
,c4 or #ba ,c4 7#fh or #gj ,f47 by the  
action of  fermentation1 which is always
 accompanied by an increase of heat4#f  
,this is not1 however1 the only reason  
for the use of the term 8high           
fermentation40 ,we have just seen that  
the fermenting casks were so  arranged  
that most of the yeast produced during  
the process of  fermentation would rise 

to the upper part of the casks and work 
out of  the bung-holes4 ,in this        
practical fact we have the actual origin
 of the  expressions 8high fermentation0
 and 8high beer10 which are used to     
distinguish this peculiar fermentation  
and the quality of beer derived  from   
it4    ,as we have already observed1 all
 beer was formerly produced by this mode
  of fermentation1 which even at the    
present time is still practised in  the 
breweries of ,great ,britain1 where beer
 fermented at a low  temperature is     
absolutely unknown4    8,low            
fermentation0 is a slow process1        
effected at a low temperature1  during  
which the yeast sinks to the bottom of  
the vats or casks4 ,the  wort1 after    
cooling1 is run into open wooden vats4  
,in cooling1 the wort  is brought to as 
low a temperature as #h ,c4 7#dg ,f471  
or even #f ,c4 7#dc  ,f471 at which     
point it is maintained by cones or      
cylinders 7styled  nageurs1 i4e41       
floats1 by the ,french7 floating in the 

fermenting vats4  ,these floats may be  
filled with ice if the outside          
temperature requires  it1 as is         
invariably the case in summer4    ,the  
duration of this fermentation is ten1   
fifteen1 or even twenty days4  ,the     
yeast1 which is produced less abundantly
 than in the case of beer  fermented at 
a high temperature1 is gathered after   
the beer has been  drawn off1 and is    
partly used in subsequent fermentations4
    ,the term 8low fermentation0 is     
derived partly from the lowness of the  
temperature during the fermenting       
process1 and partly from the fact that  
the yeast is gathered at the bottom1 and
 not at the upper part of the           
fermenting vessels4#g    ,beer fermented
 at a low temperature1 of which there   
are several  varieties1 differing in    
colour and quality1 is of ,bavarian     
origin4#h  ,the preference of the public
 for this kind of beer1 and the         
increased  facilities that such a beer  
affords the trade1 are the two reasons  

why  its manufacture has so greatly     
increased4 ,in ,austria1 ,bavaria1      
,prussia1  and other ,continental       
countries this new method of brewing is 
almost  exclusively adopted4    ,in the 
,moniteur de la ,brasserie of the #bcrd 
,april1 #ahga1 may be found  the        
following significant remarks on the    
increase in the production of  beer     
fermented at a low temperature on the   
,continent3 8,the number of  breweries  
manufacturing high beer is rapidly      
decreasing1 whilst the  number of those 
producing low beer is still more rapidly
 increasing4  ,there were in ,bohemia1  
in #ahfj1 #bha breweries in which high  
fermentation  was practised2 in #ahfe1  
only #ha of these remained2 in #ahgj1   
the number  had declined to #ah4 ,on the
 other hand1 the number of breweries    
practising low fermentation increased   
from #ace in #ahfj to #dei in #ahfe1    
and in #ahgj had risen to #hca4 ,in     
#ahfj there were #fbj breweries in which
  the two methods were employed2 in     

#ahfe there were #dhf2 in #ahgj only    
#aai  remained4 ,the number of breweries
 at present existing in ,bohemia amounts
  to #ifh40    ,in ,france1 we are still
 in a period of transition2 but year by 
year the  manufacture of 8low beer0 is  
increasing1 to the evident detriment of 
its  competitor4    ,it is unnecessary  
to dwell upon certain differences       
existing between the  two kinds of beer1
 such as may be traced to the           
preparation and  composition of their   
respective worts4 ,the brewing of 8high 
beer10 by  hand or machinery1 is        
effected in one operation2 the brewing  
of 8low  beer0 is accomplished by       
successive mashings1 the temperatures of
 which  are gradually raised4 ,these    
differences1 and others that result from
 the  longer boiling of the wort1 in the
 8high fermentation0 process1 give  rise
 to diversities in the composition and  
colour of the worts1 from  which        
circumstance 8low beers0 are sometimes  
termed white beers1 in                  

contradistinction to the others1 which  
have a deeper colour1 and are  known as 
dark beers 7bruns74 ,the name of        
,strasburg is generally  given to 8low  
beer0 in ,france1 but sometimes it is   
called ,german beer4    ,it is easy to  
account for the changes introduced into 
the construction  and working of        
breweries by the new process of 8low    
fermentation40 ,a low  temperature is   
essential not only to the manufacture   
but also to the  preservation of 8low   
beer10 and must be secured by the use of
  ice-cellars in which the temperature  
may be maintained at #e ,r4 or #f ,r4   
7#dc ,f4 or #de ,f471 and even at #a1   
#b1 or #c ,r4 7#ce to #ci ,f47          
throughout the year4 ,this necessitates 
an accumulation of ice and the          
construction of cellars of enormous     
extent1 for the storage of the beer4    
8,low beer0 is essentially a stock beer1
 especially if brewed in winter1  when  
due advantage is taken of the low       
temperature of the season4 ,it is  kept 

in cold cellars until the spring or     
summer1 when beer is consumed  in larger
 quantities4 ,it is calculated that #ajj
 kilos4 7#aif cwt47 of  ice is the      
average quantity used per hectolitre    
7#bb gallons7 of good  beer1 between the
 cooling of the wort and the day of     
sale4#i    ,in the manufacture of 8high 
beer0 we find none of these             
complications1  nor have we in that     
manufacture any similar difficulty of   
working or  expense of construction to  
contend against4 ,the whole process of  
brewing1 including the delivery of the  
beer1 does not take more than  eight    
days4 ,why should a mode of brewing so  
simple1 so rapid1 and  comparatively so 
inexpensive1 have been abandoned by the 
greater part of  ,europe in favour of a 
system disadvantageous to the brewer in 
so many  respects8 ,it would be a       
mistake to suppose that the sole reason 
for such  a change might be found in the
 superior quality of 8low beer40 ,that  
such  a superiority does exist is       

admitted as a fact by the majority of   
beer  drinkers2 but taken by itself1    
this fact is not sufficient to account  
for the radical transformation that has 
taken place in the manufacture  of beer1
 as is proved by the example of         
,england1 which1 we believe1 does  not  
possess as yet one single 8low beer0    
brewery1 from which  circumstance we may
 fairly suppose that the ,english have a
 decided  preference for 8high beer40   
,the principal advantage of working at a
 low temperature lies in the fact  that 
8low beer0 is less liable to            
deterioration1 and is less prone to     
contract diseases than 8high beer10     
especially whilst it remains in the     
brewery--a circumstance that places the 
brewer in a position vastly  superior to
 that which he occupied in former times4
 ,with the help of ice  the brewer can  
manufacture beer during winter and the  
early part of  spring1 for consumption  
in summer4#aj 8,high beer10 on the other
 hand1  must be consumed within a short 

time of its production4 ,the brewer is  
thus compelled to manufacture it as it  
is wanted1 and as orders are sent  in1  
the demand for it being in a great      
measure dependent upon the state  of the
 weather4    ,conditions so unfavourable
 as these must necessarily operate      
prejudicially against trade4 ,industry  
requires more stability and  uniformity1
 both in the production and the sale of 
its goods4 8,low beer0  can be brewed in
 large quantities at any time to be     
delivered at any  other time1 according 
to requirements2 its manufacture1       
therefore1 is  unattended by the        
inconveniences which we have just       
noticed4#aa    ,how is it that the use  
of ice and yeast operating at a low     
temperature  so greatly facilitates the 
preservation of our beer and enables us 
to  secure such striking advantages8    
,the explanation is simple3 the diseased
  ferments1 which we have pointed out1  
rarely appear at a lower  temperature   
than #aj ,c4 7#ej ,f471 and at that     

temperature their germs  cease to be    
active4 ,the adoption of low            
temperatures by brewers is  mainly due  
to this physiological fact4 ,on one     
occasion only have we met  with active  
vibrios 7,no4 #c1 ,plate ,i471 at a very
 low temperature2  these were forming   
with great difficulty in wort fermenting
 at #e ,c4  7#da ,f474    ,from this we 
see that the changes which the          
manufacture of beer has  undergone      
during the present century have been    
based mainly on the  diseases to which  
beer is liable1 either during or after  
the process of  brewing4 ,the fact that 
,english brewers have not as yet adopted
 8low  fermentation0 may be accounted   
for1 in a great measure1 by the         
difficulty of enlarging existing        
breweries1 in cities like ,london1 to   
the extent required for the new method  
of manufacture4 ,even in the event  of  
public taste demanding a 8low beer10    
,english brewers will hesitate a  long  
time before converting their breweries4 

,such conversion would  impose upon them
 expenses and difficulties of a very    
serious nature4 ,if  ever such a change 
should take place1 it will probably be  
inaugurated  out of ,london4 ,it is1    
however1 worthy of remark that ,english 
brewers1  without adopting 8low         
fermentation10 have introduced          
considerable  improvements in brewing1  
especially in the management of the     
temperature  during fermentation2 this  
must be preserved within narrow and     
exact  limits1 for fear of injury to the
 product4 ,it might easily be shown that
  these improvements have resulted from 
the liability of the beer to  contract  
diseases1 although this fact may not    
have been recognized by  the brewers who
 have introduced them4    ,besides the  
yeasts which belong to the two principal
 kinds of  fermentation1 there exist    
many varieties of alcoholic ferment that
  produce1 each of them1 a special kind 
of beer4 ,among these special beers     
some are deficient in taste1 others in  

aroma1 others in brilliancy4 ,let  us   
suppose that in the manufacture of a    
beer with one of these yeasts1  from    
which a peculiar flavour is derived1 a  
different and inferior  variety is      
accidentally mixed with that which we   
intend to use2 in such  a case1 the     
inferior variety1 the product of which  
will possess an  inferior quality1 will 
exercise such an influence on the       
brewing as to  induce the belief that   
disease must be present4 ,the           
microscope1 if  consulted1 will reveal  
no special organism1 nor any of those   
diseased  ferments of which we have     
given specimens4 ,it is in the study of 
yeast  that we must endeavour to find   
the cause of the results we observe4    
,this  point1 which is of the greatest  
importance to brewers1 will become      
clearer as we proceed4    ,if we examine
 the practices of the beer trade1 in its
 retail as well as  in its export       
branches1 we shall find that many of    
them afford evidence  of the liability  

of the beer to deteriorate4 ,we may cite
 some of these4  ,when taken out of the 
ice-cellars1 the beer is kept in casks  
of small  capacity1 that it may be the  
sooner consumed2 when exposed to a high 
temperature1 the beer will not keep     
sound for any length of time1 but  will 
speedily effloresce with mycoderma vini 
or mycoderma aceti4    ,beer which is   
intended for bottling should not be kept
 for more than a  month or six weeks4   
,even in bottling we may perceive the   
tendency of the  liquid to              
deteriorate4#ab ,it is necessary that   
the bottles1 immediately  after being   
filled1 should be laid on their sides   
for twenty-four or  forty-eight hours2  
they may then be placed upright2 the    
reason for this  is that the air left   
between the cork and the beer might give
 rise to  the production of             
efflorescence4 ,if we lay the bottles   
down on their  sides1 the oxygen of this
 air will be absorbed by the oxidizable 
substances in the liquid1 and there will

 be little fear of germs  developing    
themselves when the bottles are placed  
upright4 ,the bottles  should not1      
however1 be left on their sides longer  
than forty-eight  hours2 otherwise the  
supplementary fermentation may force the
 corks out4  ,moreover1 when the bottles
 stand upright the products of          
fermentation  collect at the bottom1 and
 not at the sides4    ,beer which is    
intended for keeping1 if exported or    
conveyed some  distance off1 must be    
surrounded with ice4 ,without this      
precaution it  will ferment too much or 
contract some disease4    8,high beer0  
cannot stand travelling4 ,this kind of  
beer should not be  exported unless the 
ordinary proportion of hops has been    
greatly  increased--hop oil acting in   
some respects as an antiseptic1 and     
preventing the beer from contracting    
diseases4#ac ,the export of ,english    
beer to ,india and the ,continent has   
fallen off of late years1 or rather1    
has not increased to the extent that was

 anticipated2 in fact1 this  trade has  
entailed great losses upon those engaged
 in it4 ,it is said  that an ,english   
firm lost as much as #dh1jjj on one     
consignment1 which  on its arrival in   
,india was found to be all turned4      
,there are no breweries in hot          
countries1 where beer would command a   
very  large sale4 ,it is a well-known   
fact that beer is a remarkably pleasant 
drink in tropical climates1 provided its
 temperature be a few degrees  below    
that of the atmosphere1 but the expenses
 of its production would  be enormous1  
on account of the immense quantity of   
ice that would be  required in its      
manufacture and for its preservation4   
,it is in hot  countries that beer is   
most liable to deterioration4    ,beer  
is said to be the beverage of northern  
regions1 which are deprived  of the     
vine1 by the rigour of their climate4   
,in these regions man has  sought in the
 abundance of grain-fruit a substitute  
for grapes4 ,to a  certain extent this  

is true2 nevertheless1 it is an         
undoubted fact that  beer was first     
brewed in ,egypt1 a very hot country1   
whence its  manufacture has spread over 
,europe4 ,it was called ,pelusian wine1 
from  ,pelusium1 a city on the banks of 
the ,nile1 which produced a beer that   
was held in high esteem4#ad    ,beyond a
 doubt1 hot countries1 even those in    
which the vine is  cultivated1 would    
consume much beer1 could it but stand   
their high  temperature4#ae ,a          
considerable quantity of beer is now    
brewed in  ,british ,india1 but its     
manufacture entails an enormous outlay  
for ice4    ,the complications which    
result from the tendency of wort and    
beer to  deteriorate1 underlie almost   
all the details of the process of       
brewing  and the sale of beer1 and have 
been the cause of most of the changes   
and  improvements that have been        
effected in brewing1 during the present 
century4    ,footnote #a3      ,this    
expression is found for the first time1 

it would appear1 in    ,theophrastus1   
,b4,c4 #cga4 ,see1 however1 ,herodotus1 
,bk4 ,,ii41 chap4 #gg4    ,speaking of  
some ,egyptians he says1 8,they drink a 
kind of wine made    from barley 7 '    
71 for the grape does not    grow in    
that part of the country40 ,herodotus   
wrote about #dej ,b4,c4    schylus 7#dhj
 ,b4,c47 has a similar expression1      
,suppl4 #iec4--;,d4 ,c4 ,r4    ,footnote
 #b3      ,one of these modifications is
 a real source of serious danger to the 
preservation of wine2 for instance1     
during rainy years1 at the time of      
vintage1 the grapes may happen to be    
covered with earthy matter1             
consisting principally of carbonate of  
lime2 this will dissolve in    wine and 
partly neutralize its acidity1 and the  
wine will thus become    more liable to 
disease4    ,footnote #c3               
,transferring from one cask to another  
for the purpose of clarifying    the    
wine4    ,footnote #d3       ,we shall  
hereafter revert to this rapidity in    

cooling1 to show that    it is also of  
use in the subsequent clarification of  
beer4    ,footnote #e3      ,in some    
breweries 7at ,lyons especially7        
fermentation at a high    temperature is
 practised in large vats at about #ae   
,c4 7#ei ,f474 ,the    yeast which      
covers the surface of the liquid is     
skimmed off and stored    in flat tubs4 
,footnote #f3      ,the initial         
temperature of the wort must be         
regulated by the quantity    of wort    
subjected to fermentation4 ,in ,english 
breweries1 where large    quantities are
 brewed at a time1 the heat created by  
the action of    fermentation would     
produce a temperature sufficiently high 
to affect    the quality of the beer1 if
 the yeast were added at #ai ,c4 or #bj 
,c4      ,the following are the         
temperatures at which the worts are     
pitched1 in    the principal ,london    
breweries3--,for common ale1 #fj ,f4 or 
#aee ,c42    for pale ale1 #eh ,f4 or   
#add ,c42 for porter1 #fd ,f4 or #agh   

,c4 ,the    fermentation is commenced in
 large vats2 from these the beer is run 
into vessels of a much smaller capacity1
 in which it completes its              
fermentation by working off the yeast   
and cleansing itself4      ,for white   
beer of superior quality1 the           
temperature during    fermentation must 
not rise beyond #gb ,f4 or #bbb ,c42    
some brewers    never allow it to exceed
 #ah;,c4 7#fe ,f474 ,the temperature is 
lowered by    means of a current of cold
 water1 which circulates through a coil 
fixed in the vats or other fermenting   
vessels4      ,in the case of porter1   
the initial heat of which is #fd ,f4 or 
#agh    ,c41 the temperature in the vats
 sometimes rises to #gh ,f4 or #bee ,c42
    but such an increase in temperature 
excites considerable apprehension4      
,we have seen a tun for pale ale1       
containing #bjj barrels of #cf gallons1 
pitched with #fjj lbs4 of fairly solid  
yeast4 ,in forty-six hours the          
attenuation was considered sufficient1  

and the beer1 which from an    initial  
heat of #eha ,f4 or #ade ,c41 had risen 
to #gb ,f4 or #bbb ,c41    was cleansed 
to working casks4 ,the large vats in    
which the    fermentation is started may
 be considered as equivalent to the     
cuves    guilloires of ,french          
breweries1 the casks in which it is     
completed    and the yeast thrown off   
representing their #ge-litre vessels1   
improperly called quarts4               
,notwithstanding the enormous ,english  
beer    manufacture1 and although the   
fermenting vat1 as in making porter1 for
    instance1 sometimes attains the     
capacity of #b1jjj to #c1jjj litres     
7#djj    to #fjj gallons71 the casks    
into which it is run are never larger   
than    #ae to #bj hectolitres 7#cjj to 
#djj gallons72 and even at ,burton1 in  
the    celebrated breweries of ,allsopp 
and ,bass1 the pale ale is finished in  
casks of a capacity less than #aj       
hectolitres1 and yet the average        
turn-out of these immense works reaches 

#c1jjj to #d1jjj hectolitres    7#fj1jjj
 to #hj1jjj gallons7 of beer per day4   
,footnote #g3      ,the expressions     
8high0 and 8low0 fermentation or beer   
strictly refer    to temperature1       
whereas the other expressions used      
78top0 or 8bottom07    refer to the     
behaviour of the yeast4 ,the ,french    
words haute and    basse seem to look   
both ways4--,d4 ,c4 ,r4    ,footnote #h3
      ,it is said that the floating     
cones or cylinders filled with ice1     
which    enable brewers to manufacture  
beer at a low temperature1 even in      
summer1 were first used in ,alsace4     
,footnote #i3      #de million kilos4 of
 ice are annually consumed in the       
brewery of ,m4    ,dreher1 in ,vienna4  
,the brewery of ,sedlmayer1 at ,munich1 
uses about #aj    million kilos4        
7,journal des ,brasseurs1 #bbnd ,june1  
#ahgc47    ,footnote #aj3      ,it      
should1 however1 be borne in mind that  
these remarks on the    relative        
preservative powers of the two beers    

hold true on account of    three        
things--differences in the respective   
modes of brewing1    artificial cooling 
during the process of fermentation1 and 
the storing    of the 8low beer0 in     
ice-cellars4 ,in itself1 perhaps1 8low  
beer0 is    more liable to change than  
8high beer20 that this does not actually
    take place1 is due to the employment
 of artificial cooling4 ,a brewery      
which has an average annual production  
of #aj1jjj hect4 will use #h1jjj    cwt4
 of ice4 ,if we add to this the ice used
 during the retail of the    beer1 which
 is best drunk at #ab ,c4 7#ed ,f471 we 
shall arrive at the    total of #ajj    
kilos4 per hectolitre4    ,footnote #aa3
      ,in connection with the comparison
 here instituted by ,m4 ,pasteur        
between the drinking and keeping        
qualities of the two kinds of beer1     
it may be useful to draw the reader's   
attention to a review by ,dr4           
,charles ,graham of the ,french edition 
of this work1 published in    ,nature   

for ,january #aath1 #ahgg1 page #baf4   
,at the same time we must    remark that
 ,dr4 ,graham appears to have overlooked
 ,m4 ,pasteur's    footnote1 page #ab1  
,english edition3--8,his assertion1 that
 by bottom    fermentation store beers  
can be produced1 whereas those produced 
by    top fermentation must be consumed 
at once and cannot be transported1      
are certainly strange to an ,englishman4
 ,so far from these unfavourable        
comparisons being true in all cases1 the
 exact opposite is generally    the     
case4 ,bavarian and other bottom        
fermentation beers are in fact    those 
which can neither be preserved nor      
transported without the    liberal      
employment of ice2 even that sent from  
,vienna to ,london must    be kept cold 
artificially1 in order to avoid rapid   
destruction4 ,as    regards flavour1    
there are many who think a glass of     
,burton pale ale1    or of good old     
,college rent ale1 to be superior to any
 ,bavarian beer4    ,the chief cause of 

the decline in the production of top    
fermentation    beers on the ,continent 
has been the want of attention in the   
fermentation process2 whereas the       
,english brewer1 especially the         
brewer of high-class ales1 has been     
unremitting in his attention to    the  
temperature in fermentation and to the  
perfect cleansing of the    ale4 ,now1  
where such attention is given1 it is not
 difficult to obtain    ales which will 
keep a few years4 ,while objecting to   
our ,english    produce being so hastily
 depreciated by ,m4 ,pasteur1 our       
brewers will    be the first to avail   
themselves of his biological researches1
 in    order to render their produce    
more stable and better flavoured1       
without having recourse to the general  
adoption of the vastly more    costly   
system of bottom fermentation40--,d4 ,c4
 ,r4    ,footnote #ab3      ,to preserve
 bottled beer from deterioration1 some  
bottlers employ1 at    the moment of    
filling1 a small quantity of bisulphite 

of lime4 ,others    heat the bottles to 
a temperature of #ee ,c4 7#aca ,f47 ,in 
the north of    ,germany and in         
,bavaria1 this practice has been widely 
adopted since    the publication of the 
author's 8,studies on ,wine10 and some  
of ,m4    ,velten's writings4 ,the      
process has been termed pasteurization  
in    recognition of the author's       
discovery of the causes of deterioration
    in fermented liquors1 and of the    
means of preserving such liquors by     
the application of heat4 ,unfortunately 
this process is less successful    in   
the case of beer than in that of wine1  
for the delicacy of flavour    which    
distinguishes beer is affected by heat1 
especially when the beer    has been    
manufactured by the ordinary process4   
,this effect would be    less felt in   
beer manufactured by the process which  
is advocated in    this work4           
,footnote #ac3      ,a convincing proof 
of the influence of hops on the ferment 
organisms    is contained in the fact   

that beer1 even after being raised to   
#fj ,c4    or #gj ,c4 7#adj or #afj     
,f471 will1 if unhopped1 readily take on
 the    butyric fermentation1 from      
which1 if hopped1 it would remain       
perfectly    free4    ,footnote #ad3    
,for historical details1 see            
l',encyclopdie1 ,art4 ,bire4            
,footnote #ae3      ,as a wine-producing
 country ,france has been highly        
favoured by nature1    but the          
consumption of beer in ,france is       
increasing every year4 ,in    #ahgc the 
quantity of beer1 paying excise duties1 
amounted to #g1dac1aij    hect41 which  
yielded to the ,treasury the sum of     
#bj1afe1acf fr4 ,these    figures are   
taken from a report published in #ahge  
by ,m4 ,jacqume1    inspector of        
finances1 who remarks that the quantity 
of beer upon    which excise duties are 
paid represents1 probably1 not more than
    one-third of the total production3  
two-thirds of the quantity brewed       
evades the duties4                      

,,chapter ,,ii4         ,on the ,causes 
of the ,diseases which affect ,beer and 
,wort4      ,from our preceding         
observations it will be evident that the
 manufacture  of beer1 the arrangement  
of breweries1 and all the processes     
practised  by the brewer immediately    
depend upon this fact1 that beer and    
wort are  fluids essentially liable to  
change4 ,thus it becomes a matter of    
extreme  importance that we should have 
an exact knowledge of the causes and    
nature of the changes which affect our  
produce1 and it may be that this        
knowledge will lead us to regard the    
conditions of the brewing industry  from
 a novel point of view1 and bring about 
important modifications in  the         
practices of the trade4 ,we might vainly
 search the numerous works  which have  
been written on brewing for information 
respecting the  proposed subject of     
these studies4 ,at the most we should   
find the  diseases to which beer is     
liable in the course of its manufacture1

 or  afterwards1 vaguely hinted at2     
perhaps we might be favoured with       
certain  empirical recipes for          
disguising the evil effects of those    
diseases4    ,it will be our endeavour  
to demonstrate the truth of the         
proposition we  have already laid down1 
that every change to which wort and beer
 are  liable is brought about solely by 
the development of organic ferments1    
whose germs are being perpetually wafted
 to and fro in the dust floating        
through the air1 or distributed over the
 surface of the different  materials and
 utensils used in brewing1 such as malt1
 yeast1 water1  coolers1 vats1 tubs1    
casks1 shovels1 workmen's clothes1 and  
innumerable  other things4    ,it is    
evident that this proposition bears a   
marked resemblance to the  one which we 
have demonstrated concerning the        
diseases of wine4#af    ,by the         
expression diseases of wort and beer1 we
 mean radical changes  which so affect  
the nature of those liquids as to make  

them unpalatable1  especially if they   
are kept2 such changes produce beer     
which is sharp1  sour1 turned1 oily1    
putrid1 and otherwise bad4 ,it would be 
unreasonable  to apply the term disease 
to certain modifications in the quality 
of  beer1 which may be produced by      
practices more or less commendable4     
,such  modifications1 too1 may result   
from want of skill in the brewer1 from  
the composition of the wort1 from the   
specific nature of the yeast1 or  from  
the inferior quality of ingredients4 ,it
 is a well-known fact that  8low beer10 
if manufactured according to the        
ordinary process1 has not  that same    
delicacy of flavour which characterizes 
beer fermented at a  lower temperature  
than #aj ,c4 7#ej ,f474 ,fermented at   
#aj ,c4 7#ej ,f471 or  #ab ,c4 7#ec ,f47
 or at a higher temperature1 it loses   
the peculiar  properties which consumers
 prize4 ,nevertheless1 in point of      
soundness it  may be as good a beer as  
one which has been fermented at #f ,c4  

7#dc ,f471  or #h ,c4 7#df ,f474 ,one   
might say of the former beer that it is 
inferior  to the latter in estimation2  
but we could not rightly call it        
diseased1  for we are supposing a case  
in which disease does not actually      
exist4       ,i4--,every ,unhealthy     
,change in the ,quality of ,beer        
coincides with a  ,development of       
,microscopic ,germs which are alien to  
the ,pure ,ferment of                   
,beer4      ,our proposition concerning 
the causes of the diseases of wort and  
beer  might be demonstrated in several  
ways4 ,the following is one of the      
simplest3--,take a few bottles of sound 
beer1 say1 for instance1 that  which is 
known in ,paris as ,tourtel's1 ,grber's1
 or ,dreher's1 from the  name of the    
brewer who manufactures it4 ,place some 
of these bottles in a  hot-water bath   
and raise the temperature to about #fj  
,c4 7#adj ,f474  ,permit them to cool1  
and then place them by the side of the  
other  bottles that have not been       

heated4 ,in every case1 especially if we
  conduct this experiment in summer1 we 
shall find that in the course of a  few 
weeks--the length of time varying       
according to the temperature and  the   
quality of the beer--all the bottles    
which have not been heated will  have   
become diseased1 in some cases even to  
the extent of being  undrinkable4 ,let  
us next examine1 by way of comparison1  
the deposits in  the heated and         
non-heated bottles4 ,we shall find      
associated with the  pure alcoholic     
ferment other organisms1 filiform and   
for the most part  very slender1 and    
either simple or articulated1 as        
represented in ,plate  ,,ii41 the design
 of which is taken from actual deposits 
occurring in beer  that had been kept   
for some time at the ordinary           
temperature4 ,a number  of bottles of   
beer which had been heated on ,october  
#hth1 #ahga1 were  compared with those  
of an equal number of bottles of the    
same beer which  had not been heated4   

,the examination took place on ,july    
#bgth1 #ahgb4 ,the  beer1 which had been
 heated to #ee ,c4 7#aca ,f471 was      
remarkably sound1  well flavoured1 and  
still in a state of fermentation4 ,as a 
matter of  fact1 we have proved by exact
 experiments that alcoholic ferments1   
heated in beer1 can endure a temperature
 of #ee ,c4 7#aca ,f471 without  losing 
the power of germination2 but the action
 is rendered somewhat  more difficult   
and slower4 ,diseased ferments1 however1
 existing in the  same medium1 perish at
 this temperature1 as they do in the    
case of wine4  ,the beer which had not  
been heated1 had undergone changes which
 rendered  it quite undrinkable4 ,its   
acidity1 due to volatile acids1 was     
higher  than that of the other beer in  
the proportion of #e to #a4 ,the beer   
which  had been heated contained  per   
cent4 of alcohol more than the other4   
,illustration3 ,plate #b4 ,appearance   
under the ,microscope of the ,deposit   
from 8,turned0 ,beer4    ,the deposits  

in the heated bottles also showed       
filaments of disease1 but  in such      
minute quantity that it was necessary to
 search many fields of  the microscope  
to discover their existence4 ,those     
which we found after  the heating must  
have existed in the beer before that    
operation2 the  heat had destroyed them1
 without sensibly altering their shape  
or size2  they could neither multiply   
nor continue to exert any influence upon
 the  components of the beer4#ag        
,from these experiments we may easily   
perceive1 on the one hand1 that  beers  
apparently sound to the taste do not    
contain these or any other  filiform    
ferments1 save in a scarcely appreciable
 quantity2 and1 on the  other hand1 that
 these same ferments appear with the    
first unfavourable  change in the       
quality of the beers1 and that they     
exist more or less  abundantly in       
proportion to the intensity of disease4 
,in certain extremely rare cases it may 
happen--so1 at least1 we have been      

assured1 but we have not proved the fact
 ourselves--that beer may keep  sound in
 bottle1 even without the preliminary   
heating4 ,this exception  can only occur
 in the case of certain beers of a      
peculiar composition1  which are highly 
hopped1 and are made during the         
favourable months of  ,november or      
,december1 out of the choicest          
materials1 and fermented with  yeast    
that happens to be pure4 ,in the deposit
 of such beer1 even after a  lapse of   
several months or several years1 we     
should find only the  ordinary alcoholic
 ferment1 the slow action of which would
 merely cause  a gradual increase in the
 quantity of alcohol existing in the    
beer1 and  a diminution in the          
proportion of dextrine4 ,this beer might
 grow old1 as  wine does1 and remain    
perfectly sound4    ,very often the     
whole work of the brewer is jeopardized 
by the  unsuspected presence of diseased
 ferments1 a remedy for which is only   
devised after the evil has evoked the   

complaints of customers4 ,in such a     
case the brewer avails himself of the   
kindness of some other brewer to  obtain
 a change of yeast--a custom which is   
recognized and valued in the  trade1    
since all managers of breweries have an 
interest in keeping it  up4 ,the brewer 
whose produce is most satisfactory      
recognizes the fact  that unforeseen    
circumstances may compel him at any     
moment to change his  yeast4    ,we have
 frequently had occasion to show that   
this necessity for a change  of yeast   
depends1 in most cases1 on some change  
brought about by the  presence of       
diseased ferments1 the multiplication of
 which has resulted  fortuitously from  
some unconscious neglect during the     
process of  brewing1 or from climatic   
influences4 ,when we reflect that yeast 
is a  living being1 and that the medium 
which serves as its aliment1 and the    
water in which it lives1 are remarkably 
well adapted for the development  of a  
vast number of other microscopic beings1

 the comparative purity of  yeast should
 surprise us even more than its         
deterioration does4    ,now by means of 
microscopical observations we might     
often detect the  existence of the evil 
long before we are warned of it by a    
defective  working1 which invariably    
entails great losses4#ah    ,in proof of
 this remark we may cite the following  
facts4 ,in the month of  ,september1    
#ahga1 we were permitted to go through a
 large ,london brewery1  in which the   
microscopical study of yeast was        
altogether unknown4 ,we  were allowed to
 make certain experiments in the        
presence of the managers  of the        
establishment4 ,we first examined porter
 yeast1 which was  collected in a       
channel that received the yeast as it   
worked out of the  fermenting vessels4  
,one of the ferments of disease abounded
 in this  yeast1 as may be seen in the  
accompanying sketch1 which was taken on 
the  spot 7,fig4 #a74 ,it was evident   
that the working of the porter was      

extremely unsatisfactory1 and had1      
perhaps1 been so for a long time2       
indeed1 we were told that they had      
obtained a change of yeast from  another
 ,london brewery that same day4 ,we made
 a point of examining this  yeast with  
the microscope4 ,it was beyond          
comparison purer than the  preceding    
yeast4    ,illustration3 ,fig4 #a4      
,it is evident that if these brewers had
 been in the habit of using the         
microscope they might have detected the 
unsoundness of their produce  before the
 time when they actually made the       
discovery1 which1 no doubt1  was forced 
upon them by the complaints of their    
customers1 or some other  annoying      
circumstance1 that led to their         
obtaining a change of yeast4    ,we next
 obtained permission to examine the     
yeast of the other beers  undergoing    
fermentation1 especially those of white 
beers1 such as ale  and pale ale4    ,in
 the sketch which we made of these      
yeasts one may detect the presence  of  

the filaments peculiar to turned beer   
7,fig4 #b74    ,illustration3 ,fig4 #b4 
,we examined with much interest the ales
 which had immediately preceded  those  
undergoing fermentation1 the yeast of   
which we had just  inspected4 ,we were  
furnished with two kinds1 both in casks1
 the one  fined1 the other not fined4   
,the latter was visibly turbid1 and1    
examining a drop of it1 we discovered   
three or four filaments present  in     
every field of the microscope4 ,the ale 
which had been fined was  nearly clear1 
but wanting in brilliancy2 it contained 
about one  filament to the field4 ,we   
asserted in the presence of the head    
brewer1  who had been summoned1 that    
these ales were extremely liable to     
change1 that it was highly necessary to 
dispose of them without delay1  and that
 they were necessarily already faulty in
 flavour--a fact which  all admitted    
after some hesitation--attributable1 of 
course1 to the  natural reluctance which
 every manufacturer feels to own that   

his  produce is not above reproach4 ,we 
were shown some of the finings used  in 
the brewery2 they were swarming with the
 same filaments of  disease-organisms4  
,we then propounded to the managers     
certain questions on the subject of  the
 losses which a brewery may sustain from
 changes in its beer4 ,we had  heard    
from several brewers that the selling   
price of beer differed so  greatly from 
the cost of its production solely in    
consequence of the  losses which the    
unavoidable waste of large quantities of
 beer was  constantly causing2 several  
brewers have in our presence estimated  
these  losses at #bj per cent4 of the   
total production1 on the average4    ,at
 first the ,english brewers returned    
somewhat vague answers to our           
questions2 however1 after what had taken
 place1 they doubtless  recognized the  
fact that a mutual understanding between
 a savant and a  practical man may often
 be of considerable benefit to the      
latter1 and in  the end they confessed  

to us that they had stowed away in their
 brewery  a large quantity of beer which
 had gone bad in cask a fortnight or so 
after it was brewed4 ,having avowed thus
 much they expressed their great        
anxiety to learn the cause of so serious
 a change in their beer1 which  was     
quite undrinkable4 ,we examined it under
 the microscope1 without  being able to 
detect immediately any diseased         
ferments1 but being aware  that the beer
 had probably been clarified1 by        
remaining undisturbed for  a very long  
time1 and that these ferments might have
 become inert and  precipitated to the  
bottom of the enormous vats containing  
the beer1 we  examined the deposits     
which had formed at the bottom of these 
vats4 ,they  were composed solely of    
filaments of disease-organisms1 without 
even the  least trace of the globules of
 alcoholic yeast4 ,the supplementary    
fermentation of this beer had evidently 
been nothing but a diseased             
fermentation4    ,the resemblance       

between these filaments and those which1
 in considerably  smaller proportion1   
accompanied the globules of alcoholic   
ferment in our  preceding observations1 
the change in the beer1 which was almost
 as bad  as beer could possibly be1     
along with an abundance of filaments1   
and the  change1 to a minor extent1 in  
that beer which only presented a few    
filaments in a field of the microscope1 
impressed those managers of the  brewery
 who were present with an entire belief 
in the theory which we  had been        
endeavouring to impress on their minds  
concerning the causes of  the badness of
 their beer4 ,some eight days afterwards
 we paid another  visit to this same    
brewery1 and learnt that the directors  
had lost no  time in acquiring a        
microscope1 and in procuring changes of 
yeast for  all the varieties of beer1   
which they had put in working since our 
first  visit4    ,there are some periods
 of the year--early spring1 summer1 and 
autumn1 for  instance--when the working 

of a brewery is a matter of great       
difficulty4  ,the preservation of yeast 
becomes a subject requiring the most    
delicate  treatment1 in consequence of  
the increase in the temperature4 ,in the
  early part of autumn the most         
important ingredients used in brewing   
are  of inferior quality2 the           
deteriorating influences which have been
 at  work have covered them with a      
variety of parasites4 ,all these        
circumstances contribute to facilitate  
the development of diseased  ferments4  
,,ii4--,the ,absence of ,change in ,wort
 and ,beer ,coincides with the ,absence 
of ,foreign ,organisms4      ,the method
 which we have just pursued in          
demonstrating the existence of  a       
relation between the diseases of beer   
and certain microscopic  organisms can  
scarcely leave a doubt1 it seems to us1 
as to the  correctness of the principles
 which we are advocating4 ,in every case
  where the microscope reveals in a     
yeast1 especially a yeast which is in  a

 state of activity1 products which are  
foreign to the composition of  alcoholic
 ferment1 properly so called1 the       
flavour of the beer is more  or less    
unsatisfactory1 according to the        
abundance or nature of these  minute    
organisms4 ,moreover1 when a finished   
beer of superior quality  loses in the  
course of time its agreeable flavour1   
and becomes sour1 it  may readily be    
shown that the alcoholic ferment in the 
deposit existing  in bottles or casks1  
although originally pure1 at least in   
appearance1  becomes gradually          
intermixed with these same filiform     
ferments or other  ones4 ,these facts   
may be deduced from what precedes2      
nevertheless1 some  prejudiced minds    
might perhaps urge that these foreign   
ferments are the  consequence of some   
diseased condition1 produced by         
circumstances of  which we know nothing4
    ,although this gratuitous           
supposition may be difficult to sustain1
 we  shall endeavour to corroborate our 

preceding observations by the method  of
 experiment which will be seen to be the
 more decisive4    ,this method consists
 in proving that beer never possesses   
any unpleasant  flavour1 so long as the 
alcoholic ferment1 properly so called1  
is not  associated with foreign         
ferments2 that this also holds good in  
the case  of wort1 and that wort1 liable
 to change as it is1 may be preserved in
 a  state of purity1 if it is kept under
 conditions that protect it from the    
invasion of microscopic parasites1 to   
which it presents not only  favourable  
nutriment1 but also a field for         
development4    ,by employing this      
second method we shall1 moreover1 have  
the advantage  of proving with certainty
 a proposition that we just advanced1   
and  showing that the germs of these    
organisms proceed from the particles of 
dust which the common air wafts about   
and deposits on every object1 or  which 
are spread over the utensils and        
materials used in a brewery1  materials 

that are naturally charged with         
microscopic germs1 which  various       
changes in the store-houses and maltings
 may multiply to an  indefinite         
extent4#ai    ,illustration3 ,fig4 #c4  
,let us take a glass flask having a long
 neck 7,fig4 #c ,a71 and holding  from  
#bej c4c4 to #cjj c4c4 7i4e41 about #i  
or #aj fl4 oz472 let us put  into it    
some wort1 hopped or not1 and then draw 
out the neck of the  flask in the flame 
of a lamp1 so as to give to it the shape
 ,b 7,fig4 #c72  let us next heat the   
liquid to the boiling point1 when the   
steam will  rush with a hissing sound   
out of the curved end4 ,we may then1    
without  further precaution1 permit our 
flask to cool1 or1 as an additional     
safeguard1 we may introduce a small     
quantity of asbestos into the open      
extremity1 at the very moment when the  
flame is taken away from the  flask4    
,before introducing the asbestos1 we may
 pass it through the  flame1 and we may 
repeat this after it has been placed in 

the end of the  tube4#bj ,the air which 
first re-enters the flask must come in  
contact  with the heated glass and the  
hot liquid1 and these will destroy the  
vitality of any germs existing in such  
particles of dust as this air may       
introduce4 ,the re-entrance of the air  
will be effected very                   
gradually--sufficiently so to enable the
 drop of water which the air1 as  it    
enters1 forces up the curved tube1 to   
catch all particles of dust4            
,ultimately1 the tube will become dry1  
but then the passage of the air  will   
proceed so slowly that every foreign    
particle will get deposited on  its     
interior sides4    ,experience tends to 
prove that external particles of dust   
cannot find  their way into flasks of   
this pattern1 having free communication 
with  the air1 at all events within ten 
or twelve years--the longest time that  
has been devoted to experiments of this 
kind2 the liquid in the flasks1  if     
originally clear1 will not become in the

 least degree contaminated1  either upon
 its surface or throughout its bulk1    
although the outside of  the flasks may 
be covered with a thick coat of dust4   
,this is an  undeniable proof of the    
impossibility of particles of dust      
finding their  way inside such flasks4  
,wort treated thus will preserve its    
purity for an indefinite time1          
notwithstanding its extreme liability to
 rapid change when exposed to  the air1 
under conditions which cause it to come 
in contact with the  particles of dust  
that air contains4 ,this also holds good
 in the case of  wine1 beef-tea1 the    
must of grapes1 and1 generally speaking1
 of all  liquids which are subject to   
putrefaction or fermentation1 and which 
possess the faculty1 when their         
temperature is raised to about #ajj;,c4 
7#bab;,f471 of destroying the vitality  
of those microscopic germs that are     
found in dust4    ,a flask such as we   
have described 7,fig4 #c7 is all that we
 require when  we have to demonstrate   

the facts that we have just reviewed1 a 
more  detailed account of which may be  
found in our ,memoir published in the   
,annales de ,chimie et de ,physique1 for
 #ahfb1 under the title ,mmoire  sur les
 corpuscules organiss en suspension dans
 l'atmosphre4 ,examen de  la doctrine   
des gnrations spontanes4 ,the shape of  
the flask  represented in ,fig4 #d only 
differs from that of the preceding one  
in  having a second little tube attached
 to the globular part of the flask2     
this presents great advantages for      
different objects of study1 and it  was 
adopted in the subsequent investigations
 detailed in this work4    ,this flask  
will permit us to study without         
difficulty every separate  kind of      
microscopic organism in the liquid best 
adapted to it without  fear1 if we take 
reasonable precautions1 that the subject
 of our study  may become associated    
with other organisms1 the accidental    
presence of  which cannot fail to       
seriously affect the results of our     

observations4    ,let us use one of     
those flasks in our experiment on yeast1
 at the same  time expressly assuming   
that the minute germs of yeast are free 
from all  contamination by foreign      
germs1 an object which we shall learn   
how to  realize by a variety of methods 
in a subsequent chapter4                
,illustration3 ,fig4 #d4    ,let us     
introduce some wort into our flask      
7,fig4 #d72 then1 after we have  fitted 
an india-rubber tube to the little      
supplementary tube1 let us  boil the    
liquid2 the steam1 finding an easier    
exit through the  india-rubber opening  
than through the drawn-out tube1 will   
rush out  through the india-rubber tube1
 and thus1 as it passes1 destroy any    
germs  which may be adhering to the     
sides of the little supplementary tube4 
,if  we close the india-rubber tube by  
means of a glass stopper1 the steam     
will immediately issue through the bent 
tube4 ,on permitting the flask to  cool1
 it will then be ready for impregnation4

 ,if there were any fear  that some     
foreign germ of an unknown nature might 
have effected an  entrance during       
cooling1 or had not been destroyed by   
the steam 7which  is always a little    
super-heated1 in consequence of the     
resistance which  it meets in escaping71
 we need only place the flasks on a warm
 stove1  and leave them there for a few 
days or a few weeks to ascertain whether
  the liquid in them has undergone any  
change4 ,we should then only use  those 
flasks which contain a sound liquid4    
,at the same time we must warn our      
readers that this cause of error does   
not exist once in a thousand times1     
especially if we use an asbestos        
stopper to prevent the entrance of      
little insects which are attracted by   
the odour of the liquid1 and which      
instinctively seek to enter at the      
extremity of the tube1 and to pass      
through it into the flask4 ,in going  so
 far1 and incurring such labour in      
search of their food1 they condemn      

themselves to certain death1 for they   
are sure to be drowned1 since it  would 
require an intelligence superior to that
 which they possess to  enable them to  
get out of the flask2 the liquid1       
morever1 could not fail  to undergo some
 change1 in consequence of the particles
 of dust that the  insects would        
introduce into it4    ,after having     
passed the flame of a spirit-lamp       
quickly over the  india-rubber tube1 the
 glass stopper1 the curved tube1 and    
even over the  fingers of the operator1 
we may withdraw the glass stopper1 and  
introduce the pure yeast by means of a  
glass pipette that has been  previously 
heated4 ,this yeast is kept in a vessel 
also free from the  dust floating in the
 air4 ,however few globules of yeast the
 glass tube  may take up1 it is sure to 
introduce a hundred or a thousand times 
more  than is necessary for the         
impregnation of the liquid4 ,the glass  
stopper  must then be replaced          
immediately1 after having been again    

quickly  passed through the flame4 ,in  
transferring our yeast from the vessel  
containing it to the flask1 by means of 
a glass pipette1 it is exposed  to      
another cause of impurity1 since we     
cannot avoid bringing it in  contact    
with the common air4 ,if this risk      
frequently troubled us in our           
experiments1 we might banish it or      
minimize it by some new arrangement2    
but this is unnecessary4 ,we have       
suffered no inconvenience from this     
cause1 as there does not exist in the   
atmosphere anything like a  continuous  
supply of that from which the so-called 
spontaneous  generation arises1 as was  
erroneously believed to be the case     
before the  publication of our ,memoir  
in #ahfb1 to which we have already      
alluded4    ,the following are the      
results of the experiments conducted in 
the manner  just described4    ,the     
yeast which we sowed1 in ever so small a
 quantity1 seemed to acquire  vigour1 to
 bud1 and to multiply4 ,soon1 that is to

 say in the course of  twenty-four or   
forty-eight hours or longer1 according  
to the  temperature1 and1 more          
especially1 the degree of vitality in   
the  globules1 we found that the sides  
of our flasks were covered with a  white
 yeasty deposit1 and noticed on the     
surface of the liquid a fine  froth1    
which at first appeared like little     
islets formed by groups of  bubbles so  
minute that they would have been        
imperceptible had they not  been joined 
together4 ,these patches increased in   
size1 and gradually  attached themselves
 to each other1 finally forming a thick 
froth4 ,in the  course of two or three  
days this froth fell1 the fermentation  
proceeded  less rapidly1 and then ceased
 completely4 ,the beer was finished4    
,this  beer might be preserved for an   
indefinite period in the flask without  
undergoing any change4 ,the external air
 passes freely into and out of  the     
flask1 as the pressure of the atmosphere
 and the temperature vary1  and the beer

 in the course of time becomes flat2 it 
acquires age in much  the same manner as
 wine does1 but it never contracts any  
taste of  disease1 it never becomes     
sour1 or sharp1 or bitter1 or putrid2 it
 does  not even become covered with     
mycoderma vini as is usually the case   
with all beer exposed to the common air 
in the course of trade4    ,after some  
weeks1 or perhaps months1 a white ring  
may show itself on the  surface of the  
liquid on the glass4 ,this is a crown   
formed by a mass of  young yeast        
globules1 which grow there like a mould1
 by absorbing the  oxygen of the air as 
it enters the flask4 ,the bulk of the   
yeast which  has been fermenting remains
 at the bottom of the liquid in the form
 of  an inert deposit4 ,this inertness1 
however1 is apparent rather than real2  
the globules may be internally active1  
without any development of new  buds1   
and the effects of this working may     
cause them to become more and  more     
languid1 and in the course of time may  

even destroy them4    ,the case is quite
 different when the yeast with which our
 wort is  impregnated1 instead of being 
pure1 is mixed to any extent whatsoever 
with diseased ferments4 ,should there be
 any of these in the yeast with  which  
we impregnate our wort1 even though     
their quantity were so  infinitesimal   
that the most skilful observer could    
scarcely discover  them with the        
microscope1 they would multiply in the  
flask after the  beer had been finished1
 especially if the beer were left for a 
short  time on a stove4 ,in this manner 
we may secure an excellent test of the  
original purity of the yeast which we   
employ in the impregnation of our  wort4
    ,thus it may be seen that the       
absence of microscopic organisms that   
are  foreign to the nature of pure yeast
 may invariably be noticed in the  case 
of a beer which is sound1 and which will
 remain sound for any  length of time1  
when in contact with pure air1 at any   
temperature4 ,we  may see1 too1 that the

 presence of these organisms may        
invariably be  detected in an unsound   
beer1 the peculiar unsoundness of which 
depends  upon the peculiar species of   
the organisms contained in it4 ,it would
 be  difficult to adduce clearer proofs 
than those which we have given as to    
the intimate relation existing between  
these organisms and the  deterioration  
of beer4 ,the relation between cause and
 effect1 in the  succession of physical 
phenomena in general1 is established by 
proofs  that are by no means more       
decisive4    ,footnote #af3      ,a     
statement of this proposition1 as far as
 it concerns beer1 appeared    first in 
outline in the author's ,etudes sur le  
vin1 published in    #ahff4    ,footnote
 #ag3      ,as the deposit in the heated
 bottles is1 as a rule1 inconsiderable1 
it    is necessary to exercise some     
precaution in collecting it4 ,the       
bottles    are taken up2 after some     
days' rest they are decanted very       
carefully1    with as little shaking as 

possible1 until not more than one or two
    cubic centimetres 7about a          
tea-spoonful7 of the liquid remains at  
the    bottom4 ,the bottles are then    
shaken vigorously1 with the object of   
collecting the whole of the deposit from
 the bottom and the sides into    this  
small quantity of liquid2 a drop of this
 is then examined under    the          
microscope4    ,footnote #ah3           
,since the publication of the author's  
8,studies on the ,diseases of    ,wine1 
and the ,dangers resulting to ,wine and 
,beer from the ,microscopic             
,parasites found therein10 some         
intelligent brewers have derived        
considerable profit from the application
 of the theories laid down in    that   
work4    ,footnote #ai3      ,if we put 
a handful of germinating barley from a  
maltster's cistern    into a little     
water1 and examine drops of the liquid1 
after it has    become turbid1 under a  
microscope1 we shall be amazed at the   
wonderful    number of strange          

microscopic organisms that swarm on the 
surface of    the grains and on the     
sides of the cistern4 ,there is no doubt
 that    their presence is injurious to 
germination1 inasmuch as they absorb    
much oxygen2 moreover1 they acidify the 
grain and cause it to    deteriorate4   
,footnote #bj3      ,in these           
experiments the asbestos is only        
introduced by way of extra              
precaution4 ,originally1 in his early   
experiments in connection with    the   
subject of spontaneous generation1 the  
results of which were    published in   
#ahfj-fb1 the author did not use it1 and
 he observed no    ill effects resulting
 from the omission2 now1 however1 he    
constantly    makes use of it4 ,in      
studies of this kind novel precautions  
are never    thrown away2 moreover1 the 
presence of this asbestos is a sure bar 
to    the entrance of insects4 ,the     
author has preserved for a long time a  
flask1 in the slender neck of which an  
insect is contained2 he killed    it    

with a flame just as it was approaching 
the liquid4 ,quite recently1    ,m4     
,calmettes1 a young engineer from the   
cole ,centrale1 when engaged1    at     
,tantonville1 in ,tourtel's brewery1 in 
carrying out certain    practical       
experiments in connection with the      
process that will he    described in one
 of the later chapters of this work1    
wrote complaining    that his flasks had
 been suddenly invaded by a swarm of    
aphides1    scarcely larger than        
phylloxeras1 and that many of them had  
even    penetrated into the inside of   
the curved tubes4                       
,,chapter ,,iii4               ,on the  
,origin of ,ferments properly so called4
      ,the new process of brewing1 which
 it is the principal object of this     
work to explain1 and which will follow  
as an immediate and inevitable          
deduction from the novel facts herein   
demonstrated1 cannot be fully           
understood without a knowledge of all   
the principles upon which it is         

founded4 ,one of the most essential of  
these has reference to the purity  of   
our fermentation4 ,we should gain but   
little from the use of a yeast          
uncontaminated by any foreign germs if  
natural organic substances had  the     
power of organizing themselves by means 
of spontaneous generation1  or by some  
transformation which took place amongst 
them1 or even by a  conversion of       
certain microscopic beings into certain 
others4 ,theories  of this kind are     
still warmly advocated1 but1 to our     
thinking1 rather  from sentimental      
considerations or prejudice than from   
any basis of  serious experimental      
proofs4    ,be this as it may1 we must  
free our minds from all suppositions    
which  might qualify the exactness of   
the principles upon which our new       
process  is founded1 or cause any doubt 
in the minds of our readers as to the   
possibility of its application and the  
benefits to be derived from its         
adoption4          ,i4--,on the         

,conditions which cause ,variations in  
the ,nature of the                      
,organized ,products existing in        
,infusions4      ,we have proved by     
experiment1 in the preceding chapter1   
that a few  minutes' boiling renders    
liquids1 and more especially wort1      
absolutely  free from liability to      
change when in contact with pure air1   
that is1  air which contains none of the
 germs of organisms that are continually
  floating about in the atmosphere4     
,what is true in the case of wort is    
equally so in the case of all  organic  
liquids2 there is not a single one that 
could not be rendered  inaccessible to  
any subsequent change if it were        
brought1 first of all1  to a suitable   
temperature1 which would vary with the  
nature of the  liquids4 ,amongst them   
there are some which1 like vinegar1 lose
 their  tendency to change after having 
been rapidly raised to a temperature of 
not more than #ej ,c4 7#abb ,f472       
others1 like wine1 require a greater    

heat4 ,wort1 to which no hops have been 
added1 should be subjected to a         
temperature of not more than #ij ,c4    
7#aid ,f472 milk to about #aaj ,c4      
7#bcj ,f474#ba    ,it is easy to show   
that these differences in temperature1  
which are  required to secure organic   
liquids from ultimate change1 depend    
exclusively upon the state of the       
liquids1 their nature1 and1 above all1  
on the conditions that affect their     
neutrality1 whether towards acidity  or 
alkalinity2 for it is not difficult to  
observe that the least changes  in these
 respects lead to considerable          
variations in the temperatures  which we
 must employ4#bb ,we could adduce many  
examples of this4 ,the  only difference 
between the nature of must and that of  
wine is caused by  fermentation4 ,we may
 say the same thing of wort and beer1   
and1 better  still1 of new milk and sour
 milk4 ,must1 to be secured from change1
  requires a much higher temperature    
than wine does2 similarly1 wort         

requires a much higher temperature than 
beer4 ,milk must be heated to  about    
#aaj ,c4 7#bcj ,f471 as we have just    
stated1 but sour milk would  require #bj
 ,c4 or #cj ,c4 7#cf ,f4 or #ed ,f47    
less4 ,wine1 when fresh1  ceases to be  
liable to change after it has been      
brought to a temperature  below #ajj ,c4
 7#bab ,f472 it requires a temperature  
of more than #ajj ,c4  in the presence  
of carbonate of lime4    ,as regards the
 explanation of the influence which     
acidity or alkalinity  exerts in        
diminishing or increasing the           
temperature required to protect         
infusions and organic matters from      
ultimate change1 although this is a     
subject which claims special study1 we  
are inclined to believe that  acidity   
permits1 and alkalinity prevents1 the   
penetration of moisture  into the       
interior of the cells of the germs      
belonging to infusions1 so  that in     
heating the outer cases of these cells  
in an alkaline medium we  heat the germs

 in a dry state2 and in heating the     
outer cases in an acid  medium we heat  
the germs when they are moist4 ,we all  
know that these  conditions make a great
 difference in the resistance which     
bodies offer  to the action of heat4 ,a 
particle of mould which1 in a moist     
state1  cannot survive a temperature of 
from #fj ,c4 to #ajj ,c4 7#adj to #bab  
,f471 will preserve its fecundity even  
if heated to #abj ,c4 7#bdh ,f471 if  it
 has been previously well dried4#bc     
,the nature of the spontaneous          
productions which we see appear in      
organic  liquids is affected to a       
remarkable extent by the smallest change
 in the  compositions of those liquids4 
,generally speaking1 as we have often   
proved in our former works1 a feeble    
acidity is unfavourable to the          
development of bacteria and infusoria1  
and1 on the other hand1  favourable to  
the growth of mould4 ,a liquid which is 
neutral or of  feeble alkalinity behaves
 in an exactly inverse manner4    ,those

 who support the theory of spontaneous  
generation seek to find in  the natural 
differences between the organic         
productions of various  liquids which   
are simultaneously exposed to the same  
atmosphere1 an  argument in favour of   
their doctrine4 ,these differences1     
however1 are  only an effect of the     
greater or less fitness of a peculiar   
liquid for a  certain kind of growth4   
,when an acid organic liquid1 such as   
the must of  grapes for example1 is     
exposed freely to the air1 it is        
besieged  simultaneously by spores of   
mucedines1 as well as germs of bacteria1
  leptothrix1 vibrios1 c41 but the      
latter germs are checked in  their      
development1 if1 indeed1 they are not   
actually destroyed1 by the  acidity of  
the liquid2 and we should never find    
them there in their  adult state4       
,most moulds1 on the other hand1 thrive 
in acid liquids1 and therefore  they are
 generally found alone4 ,if we began by 
saturating must with  carbonate of lime1

 previously dried or otherwise1 we      
should observe  opposite phenomena2     
bacteria1 lactic ferments and butyric   
vibrios would  invade our fields long   
before the spores of mould had time to  
grow1  since the germination of these   
proceeds very languidly in neutral or   
alkaline liquids1 and an infusion once  
occupied by a living organism has  much 
trouble in nourishing others2 the early 
developments consume the  alimentary    
substances1 especially the oxygen4      
,differences as marked as these in the  
adaptability of certain liquids to      
certain growths give rise to innumerable
 illusions1 and are one of the  chief   
sources of error in the study of this   
subject4 ,if we sow in an  acid liquid1 
such as must1 an alcoholic ferment1 the 
development of  which is not arrested by
 the acid character of our medium1 it   
will  multiply there1 and we shall have 
no difficulty in growing it over and    
over again in the same acid medium4     
,this being the case1 let us suppose    

that our alcoholic ferment is           
impure--let us say1 mixed with filaments
 of  turned wine1 which are due to a    
ferment checked in its development by   
the peculiar qualities of the must4 ,in 
repeating the growth of this  alcoholic 
ferment in the must the filaments which 
were1 by supposition1  present in our   
first sowing1 and which cannot reproduce
 themselves in  the must1 or do so with 
great difficulty1 will become very      
scarce in the  fields of our microscope2
 they will not1 however1 cease to exist1
 for  the repetition of our attempts to 
grow them only serves to spread the     
original germs over a larger surface2   
and1 although the eye fails to  detect  
them1 they will only have become more   
difficult to discover4 ,at  this point  
the experimentalist is in danger of     
falling into error1 for  when he no     
longer perceives the foreign ferment he 
will be inclined to  believe that it has
 vanished1 and that he may regard the   
alcoholic  ferment as being free from   

all impurity1 without testing for the   
purity  by a direct experiment4    ,an  
example of this mistake is to be found  
in a recent work by ,m4 ,jules  ,duval4 
,this writer has published a theory     
according to which yeast  becomes       
transformed into lactic ferment1 and    
likewise into other  ferments--that of  
urea1 for example--the only condition of
 change1  according to ,m4 ,jules       
,duval1 being that we should cultivate  
it in  suitable mediums4 ,the proofs by 
which he supports his conclusion are    
altogether inadmissible1 and a simple   
glance at his experiments enables  us to
 detect innumerable causes of error4 ,m4
 ,duval believes that yeast  becomes    
transformed into lactic ferment from the
 fact that he obtained a  fermentation  
which furnished lactate of lime and     
lactic ferment from  some sour milk to  
which he had added some glucose1 chalk1 
and phosphate  of ammonia before        
impregnating it with yeast2 but he took 
no steps to  secure himself against     

introducing into his medium--which was1 
as a  matter of fact1 well adapted to   
lactic fermentation1 inasmuch as it was 
a little alkaline--an alcoholic ferment 
containing impurities4 ,this was  the   
crucial point in his experiments4 ,m4   
,duval recognizes this1 but he  deceives
 himself when he says1 without          
proof3--8,my alcoholic ferment is  pure1
 for ,i have grown it over and over     
again in must1 preserved in  flasks     
prepared after the manner of those which
 ,m4 ,pasteur uses in his  experiments40
 ,here we have merely a simple          
assertion2 a direct  experimental test  
might have proved that the yeast was    
impure4    ,yeast cannot transform      
itself into lactic ferment4 ,no matter  
what the  medium may be in which it is  
sown1 if it is actually pure it will    
never present the least trace of lactic 
ferment or of any other  ferments4 ,by  
certain changes in the nature of the    
medium1 the  temperature1 and other     
conditions1 the cells of the ferment may

 become  oval1 elongated1 spherical1 and
 larger or smaller in size1 but they    
will  never produce the most minute     
quantity of lactic ferment or lactic    
acid4  ,the whole theory of the         
transmutation of ferments1 which ,m4    
,duval has  published1 is imaginary4#bd 
,we have asserted that the source from  
which we obtain our supply of the       
substances that we expose to contact    
with the air may likewise furnish a     
reason for the development of vegetable 
or animal organisms which make  their   
appearance in our infusions4 ,this may  
be easily understood4 ,if we  expose the
 infusions to temperatures more or less 
high1 with the object  of destroying the
 vitality of the germs which they may   
contain1 we  completely suppress all    
germs originating from two different    
sources--those which the infusions may  
have acquired directly from the         
atmospheric air1 or from the dust upon  
our utensils1 and those which may  have 
been introduced by the materials used in

 manufacturing our  infusions or        
decoctions1 which materials must have   
been brought from  some distance4 ,an   
infusion1 after having been heated to a 
sufficient  degree1 can harbour and     
nourish only such germs as are conveyed 
to it by  the air after the heating4    
,these floating germs are far from being
 as  varied in their nature as it       
pleases those to believe who are tied   
down  by their arbitrary and faulty     
interpretation of the knowledge that we 
have acquired1 and the discussions in   
which we have taken part1 during  the   
last fifteen years4 ,air1 unless in     
violent agitation1 can hold only  the   
most minute particles in suspension4    
,the observations which have  been      
recorded concerning organisms of        
spontaneous growth found in  infusions1 
have always been made in sheltered      
places--in rooms or  laboratories1 the  
atmosphere of which is1 relatively      
speaking1 very  still4 ,for this reason1
 in liquids that have been subjected to 

heat1 the  flora and fauna--if we may   
use such an expression--are very poor1  
and  all the more so because1 as we have
 recently had occasion to remark1 a     
great number of the organisms which     
would spring into existence of their    
own accord1 if they were allowed        
sufficient time for germination1 are    
kept back by others of a more rapid     
development4 ,the truth of this is      
evident from the fact that we may       
observe greater variations in the       
nature and number of species of living  
organisms1 if we divide one  infusion   
amongst several vessels which are       
immediately closed up again1  than if we
 leave our infusion in contact with an  
unlimited volume of  surrounding air4   
,by this means we expose each portion of
 the liquid to  no other germs than     
those existing in a state of suspension 
in the  volume of air introduced into   
the vessels2 and it so frequently       
happens  that we obtain a variety of    
germs which1 coming into contact with a 

liquid adapted to their nutrition1      
without having mixed with others1       
finally multiply there1 in consequence  
of no other organisms of greater        
activity occurring to impede their slow 
and laborious propagation4    ,the      
nature of the products resulting from   
raw infusions--that is1 those  obtained1
 without heating1 from the maceration of
 organic substances1  such as leaves1   
fruits1 grains1 or the organs of plants 
or animals--is  much more varied4 ,the  
reason of this is that such substances  
generally  carry with them not only the 
particles of dust existing in air that  
is  in motion1 but also microscopic     
parasites1 which find a congenial       
resting-place on their surface or its   
vicinity4 ,we may cite a few  accurate  
observations on this point1 for the     
subject is one of great  interest4      
,if we boil an infusion of hay1 and then
 expose it to contact with the  air in a
 room1 all its productions will be      
derived from such germs as a            

comparatively still air can carry about2
 thus1 we shall very rarely find  any   
colpoda in our infusion1 for the germs  
of these infusoria1  consisting of      
rather large cells1 can scarcely exist  
in a state of  suspension in motionless 
air1 in spite of their extraordinary    
diffusion  in nature4 ,on the other     
hand1 we almost invariably find colpoda 
in  macerations of raw hay4 ,this       
difference is easily accounted for2 the 
particles of dust adhering to the       
surface of hay1 especially that which   
comes from marshy districts1 contain the
 germ-cells of colpoda in  abundance4   
,the reason is obvious2 rain falls on a 
meadow and forms  little pools of water 
about the roots of the herbs that grow  
there2 this  water remains for some     
time1 and very soon swarms with a       
multitude of  infusoria1 especially     
colpoda4 ,dryness follows2 the colpoda  
becomes  encysted1 and forms a dust that
 is wafted by the winds on to the blades
  of grass1 so that the mower will carry

 away not only his hay1 but also        
myriads of colpoda1 as well as spores of
 mucedines and other  organisms4#be     
,the maceration of pepper will give us  
some infusoria hardly ever found  in    
other infusions1 the reason of this     
being that such infusoria exist  where  
the pepper grows--in other words1 their 
germs are exotic4 ,that the  infusion of
 a special plant should give us special 
infusoria1 is  scarcely more surprising 
than the discovery of a particular      
parasite or  insect existing on a       
particular plant1 and not on others of a
 different  species that grow near it4  
,thus it happens that the ferment-germs 
of  must exist on the surface of grapes1
 whether detached or in clusters4 ,it   
is only natural that we should find the 
organ or the plant that is  destined    
later on to become the food of a        
parasite serving as a  habitation for   
the germs of that parasite4             
,,ii4--,experiments on ,blood and ,urine
 taken in their ,normal ,state1 and     

,exposed to ,contact with ,air that has 
been ,deprived of the ,particles of     
,dust which it ,generally holds in      
,suspension4      ,recourse to the      
application of heat1 in the first place1
 is an excellent  means1 as we have just
 seen1 of procuring organic liquids free
 from all  disturbing germs2 but there  
is a still more remarkable and          
instructive1  we may even say more      
unlooked for1 method of securing this   
result1 which  may be described as in   
some measure borrowed from the nature of
 things4  ,it consists in seeking purity
 in the natural liquids of animals and  
plants4 ,it is difficult to understand  
how the liquids circulating in the      
organs of animal bodies1 such as blood1 
urine1 milk1 amniotic fluid1 and  so on1
 can possibly secrete the germs of      
microscopic organisms4 ,there  would be 
excellent opportunities for these germs 
to propagate themselves  if they        
actually did exist in the liquids       
appertaining to the animal  economy4    

,life in all probability would become   
impossible in the presence  of such     
guests4 ,a proof of this is to be found 
in the multitude of  diseases which many
 of the greatest minds of modern times  
attribute to  parasitic developments of 
this nature4 ,medical men of high       
authority  agree in thinking that the   
questions of contagion and infection    
will  find solutions from the obscurity 
in which they are now involved in a     
careful study of ferments1 and that     
hygienists and physicians should  labour
 to secure by every possible means the  
destruction of the germs of  ferments1  
and should strive to check their        
development1 and prevent  the evils     
which they cause when developed4 ,great 
progress has already  been made in this 
direction1 and we deem it a signal      
honour that our  researches on the      
subject have been considered1 even by   
those by whom  this progress has been   
accomplished1 as the source from which  
they  derived their first inspirations4 

,we shall1 doubtless1 be excused by our 
readers if we recall this fact in       
relating certain historical details     
which are especially necessary in order 
that they may comprehend the  principles
 that we are endeavouring to explain in 
these 8studies40    ,it is a matter of  
regret to us1 however1 that the facts   
which we have  established should have  
been accredited with any importance     
beyond that  which is their due4 ,the   
exaggeration of novel ideas invariably  
leads to  a reaction1 which1 again1     
overshooting the mark1 brings into      
disrepute  even those points in which   
such ideas are perfectly just1 or1 at   
all  events1 worthy of serious          
consideration4 ,there are certain       
symptoms of  such a reaction in the case
 of our theories3 they are evident in   
the  tendency of unreflecting minds to  
give a total denial to the fact that    
certain diseases may be derived from    
certain ferments--organized and  living 
ferments--of the nature of those which  

have been discovered in the  course of  
the last twenty years4 ,we should be    
guided by facts1 whichever  side of the 
question we espouse1 and by facts alone 
we should test the  truth of doubtful   
discoveries4 ,we are but on the         
threshold of the  exploration of our    
subject1 and we should strive to        
discover new facts  in connection with  
it1 and should deduce from these1       
whatever they may  be1 only such        
conclusions as they may strictly        
warrant4 ,unfortunately1  there is      
amongst physicians a tendency to        
generalize by anticipation4  ,many of   
them are men of rare natural or acquired
 talent1 endowed with  keen powers of   
intellect1 and the art of expressing    
themselves fluently  and persuasively2  
but the more eminent they are1 the more 
they are  occupied by the duties of     
their profession1 and the less leisure  
they  have for the work of              
investigation4 ,urged on by that thirst 
for  knowledge which belongs to superior

 minds1 and perhaps1 in some measure1   
through associating with the upper      
classes of society1 which are  becoming 
more and more interested in science1    
they eagerly seize upon  easy and       
plausible theories1 readily adapted for 
statement which is  general and vague   
just in proportion to the unsoundness of
 the facts on  which they are based4    
,when we see beer and wine undergo      
radical changes1  in consequence of the 
harbour which those liquids afford to   
microscopic  organisms that introduce   
themselves invisibly and unsought into  
it1 and  swarm subsequently therein1 how
 can we help imagining that similar     
changes may and do take place in the    
case of man and animals8 ,should we1    
however1 be disposed to think that such 
a thing must hold true1 because  it     
seems both probable and possible1 we    
must1 before asserting our  belief1     
recall to mind the epigraph of this     
work3 the greatest  aberration of the   
mind is to believe a thing to be1       

because we desire  it4    ,one of the   
most distinguished members of the       
,academy of ,medicine1 ,m4  ,davainne1  
who was the first to give his attention 
to rigorous  experiments on the         
influence that organic ferments exercise
 on the  production and propagation of  
infectious diseases1 declares that the  
idea of his researches on splenic fever 
and malignant pustule was  suggested to 
him by his perusal of our work on       
butyric fermentation1  published in     
#ahfa4 ,in #ahej this gentleman and ,m4 
,rayer discovered in the  blood of      
animals attacked by these diseases      
minute filiform bodies1 to  which they  
paid little attention1 and which ,m4    
,davainne recollected1  when he came    
across our ,memoir4 ,he had the         
foresight to conjecture--a  conjecture  
that was soon confirmed most decisively 
by his  researches--that the former     
disease1 known under the name of sang de
  rate1 might be the production of a    
fermentation analogous to the  butyric1 

in which the minute filiform bodies     
observed by ,rayer and  himself1 in     
#ahej1 played the part which vibrios    
fill in butyric  fermentation4 ,within  
two years of this the first works of    
,messrs4 ,coze  and ,feltz appeared4    
,these clever and courageous            
experimentalists avowed  that their     
beautiful researches had been suggested 
to them by the  perusal of my work on   
putrefaction1 published in #ahfc4 ,we   
might also  quote the striking and      
admirably conceived experiments of ,dr4 
,chauveau1  on castration4#bf ,we       
cannot1 however1 refrain from           
reproducing here a  letter addressed to 
us in #ahgd by the celebrated ,edinburgh
 surgeon1 ,mr4  ,lister3--              
8,edinburgh1 ,feb4 #aj1 #ahgd4          
8,,dear ,,sir1--,will you permit me to  
beg your acceptance of a pamphlet       
which ,i forward to you by this post1   
and which describes certain             
inquiries into a subject upon which you 
have thrown so much      light--the     

theory of germs and fermentation8 ,it   
gives me pleasure to      think that you
 will peruse with some interest what ,i 
have written      about an organism that
 you were the first to study in your    
,memoir on      lactic fermentation4 ,i 
do not know if you ever see the records 
of      ,british surgery4 ,if you have  
perused them you may have observed from 
time to time notices of the antiseptic  
system which ,i have been               
endeavouring for the last nine years to 
bring to perfection4 ,permit      me to 
take this opportunity of offering you my
 most hearty thanks      for having     
demonstrated by your brilliant          
researches the truth of      the theory 
of putrefactive germs1 and for having   
afforded me in this      manner the sole
 means of perfecting the antiseptic     
system4        8,should you ever come to
 ,edinburgh ,i am sure that you will be 
truly      gratified to see in our      
hospital the extent to which the human  
race      has profited by your work4 ,i 

need hardly add1 that ,i should have    
great satisfaction in showing you how   
greatly surgery is indebted to      you4
        8,excuse the freedom which ,i   
have taken in addressing you1 on the    
grounds of our common love for science1 
and believe in the profound      esteem 
of yours1 very sincerely1 ,,joseph      
,,lister40    ,the wad dressing of ,dr4 
,alphonse ,gurin1 surgeon at the        
,htel-,dieu1  ,paris1 which has already 
rendered great assistance to surgery1   
and has  been the subject of a very     
favourable report at the ,academy of    
,sciences  in ,paris1 was invented by   
its author in consequence of certain    
reflections suggested to him by the     
perusal of our researches4 ,the         
commission which framed the report made1
 through ,m4 ,gosselin1 some wise       
reservations in the case of certain     
theoretical ideas which ,m4 ,gurin  had 
not sufficiently proved by experiment4  
,we have no doubt1 however1  that when  
the matter is thoroughly examined1 facts

 will confirm the  truth of the wide    
views entertained by the surgeon of the 
,htel-,dieu4    ,dr4 ,dclat has founded 
quite a new system for the treatment of 
infectious diseases1 which is based upon
 the use of one of the best  known      
antiseptics1 phenic acid4 ,his theory1  
which he affirms was  suggested to him  
by our studies on fermentations1 is1    
that the diseases  which transmit       
themselves are1 each of them1 the       
product of a special  ferment1 and that 
both medical and surgical professors of 
therapeutics  should make it their study
 to prevent exterior ferments from      
penetrating  into the liquids of our    
economy1 or in the event of these       
ferments  having found their way into   
the system1 to discover antiferments for
  their destruction1 without effecting  
any change in the vitality of the       
histological elements of the liquid or  
tissues4    ,there is no doubt that     
extreme caution must be exercised in    
dealing with  questions of this kind1 as

 ,m4 ,sdillot has authoritatively       
remarked2 but  at the same time it      
cannot be denied that the more such     
questions are  discussed with exactness1
 the more those celebrated practitioners
 who  originated them are confirmed in  
the ideas which first guided them4 ,we  
may give another example of this4    ,in
 #ahgd1 in consequence of a             
communication addressed to the ,academy 
of  ,sciences by ,messrs ,gosselin and  
,a4 ,robin1 on the subject of ammoniacal
  urine1 we made the observation that we
 should endeavour to ascertain if1  in  
all such cases1 the urinary fluids were 
not rendered ammoniacal by  the presence
 of the little ferment of the urea1     
which we have previously  noticed1#bg   
and which has since then been discussed 
with remarkable  intelligence by ,m4    
,van ,tieghem1 in the thesis which he   
maintained for  his doctor's degree4    
,the suggestion and the considerations  
that  justified it led to a discussion  
before the ,academy of ,medicine1 in    

which contrary opinions were maintained4
 ,we lost no time in submitting  these  
to the test of facts4 ,we could not find
 a single person suffering  from        
ammoniacal urine1 in whose case the     
little ferment which we  mentioned was  
not to be detected4 ,our predictions    
were thus completely  justified4    ,as 
early as #ahfd the ,gazette             
,hebdomadaire de ,mdecine et de         
,chirurgie  published an account of     
urine made ammoniacal in the bladder1   
the author  of which1 ,dr4 ,traube1     
makes the following observations3--8,it 
was believed  that1 in consequence of   
the retention of the liquid1 and the    
resulting  distension of the bladder1   
that organ became irritated and produced
 a  larger quantity of mucus1 and that  
this mucus was the ferment which  caused
 the decomposition of the urea1 by      
virtue of a chemical action  peculiar to
 itself4 ,this belief can no longer be  
held in presence of ,m4  ,pasteur's     
discoveries4 ,this observer has         

demonstrated1 in the most  conclusive   
manner1 that ammoniacal fermentation1   
like alcoholic and  acetic1 is produced 
by living beings1 whose pre-existence in
 the  fermentable liquid is a necessary 
condition of the process4 ,the          
preceding fact offers a remarkable proof
 of ,m4 ,pasteur's theory4 ,in  spite of
 the long duration of the retention1    
alkaline fermentation was  not produced 
by an excessive secretion of the vesical
 mucus or of pus3  it only began from   
the moment when the germs of vibrios    
passed from the  outside into the       
bladder40#bh    ,finally1 we may        
conclude with perfect truth that the    
liquids of our  economy1 blood and      
urine1 for instance1 may afford a       
harbour to  different ferments1 even in 
the inmost parts of the organs1 when    
external causes enable such ferments to 
find their way into those  liquids1 and 
that diseases of greater or less gravity
 result from this  cause4 ,on the other 
hand1 it must be admitted that the      

bodies of animals  in a state of health 
afford no means of entrance to these    
external  germs4 ,at the same time1     
direct experiment alone can convince the
 mind  as to the truth of this latter   
assertion4 ,let us take some of the     
substances that are to be found inside  
living animals in perfect health1  and  
expose them1 in the same condition in   
which life has formed them1 to  contact 
with pure air4    ,illustration3 ,fig4  
#e4    ,illustration3 ,fig4 #f4    ,for 
this purpose we must provide ourselves  
with a glass flask1 joined to  a copper 
tap by means of an india-rubber tube1 as
 shown in ,fig4 #e4 ,the  two branches  
of the tap should be about twelve       
centimetres long 7about  -in471 the one 
which is free tapering off like the end 
of a pipe4 ,in  order to destroy all    
germs which may exist in the flask1 we  
must join  the free end of the copper   
tube to a platinum tube kept at a very  
high  temperature1 after having         
carefully introduced into the flask a   

small  quantity of water1 and expelled  
all the air by converting the water into
  steam4 ,then as we allow the flask to 
cool1 the air which re-enters it  will  
necessarily pass through the hot tube   
7,fig4 #f74    ,illustration3 ,fig4 #g4 
,we may cause the water in the flask to 
boil at a temperature of more  than #ajj
 ,c4 7#bab ,f47 by fitting to the free  
end of the platinum tube a  glass tube  
bent at right angles1 which we plunge to
 any depth in a deep  vessel filled with
 mercury 7,fig4 #g74 ,whilst the water  
is boiling under  pressure1 we must     
separate the tube which is plunged in   
the mercury2 the  water in the flask    
will continue to boil at the ordinary   
pressure4 ,we  must then leave the flask
 to cool4 ,it will gradually become     
filled with  air that has been heated to
 a high temperature1 more than          
sufficient to  burn up all the organic  
particles of dust which that air could  
have  contained4 ,when the flask is cold
 we must close the tap and detach it1   

and proceed to prepare other similar    
flasks4 ,it will be advisable to  close 
the tap when the temperature of the     
flask is still a few degrees  above that
 of the surrounding atmosphere3 this    
precaution will cause the  air in the   
cooled flask to have a lower pressure   
than that of the  external atmosphere4  
,during the interval which must elapse  
between the preparation and the  use of 
a flask1 it is a good thing to keep the 
free branch of the tap  inclined towards
 the ground1 to secure the inside of its
 tube from the  deposit of external     
particles of dust4 ,whether this        
precaution be  adopted or not1 we must  
take care to heat this branch in the    
flame of a  spirit lamp just before we  
bring our flask into requisition4    ,if
 we have to study blood1 we must take it
 from a living animal--a dog1  for      
example4 ,we must expose a vein or an   
artery of the animal1 and make  an      
incision into which the end of the free 
tap-branch1 which has  previously been  

heated and allowed to cool1 must be     
introduced and fixed  by a ligature in  
the vein or artery4 ,on opening the tap1
 the blood will  rush into the flask2 it
 must then be closed1 and the flask     
placed in an  oven at a certain         
temperature4 ,we have successfully      
accomplished these  manipulations1      
thanks to the kind help of our          
illustrious colleague and  friend1 ,m4  
,claude ,bernard4    ,the operation is  
nearly the same in the case of urine4   
,the end of the  free branch of the tap 
is introduced into the passage of the   
urethra2  the tap is turned at the      
moment when the urine is emitted1 which 
is then  allowed to pass into the flask1
 until it is a third or half filled4    
,the following were the results of our  
experiments3--,blood underwent no       
putrefactive change even at the highest 
temperatures of the atmosphere1  but    
retained the odour of fresh blood1 or   
acquired the smell of lye4  ,contrary to
 what we might have expected1 the direct

 oxidation of the  constituents of blood
 by slow combustion was rather sluggish4
 ,after  subjecting our flasks to a     
temperature of #be ,c4 or #cj ,c4 7#gg  
,f4 to  #hj ,f47 in an oven for several 
weeks1 we observed an absorption of not 
more than #b or #c per cent4 of oxygen1 
which was replaced by a volume of       
carbonic acid gas of about an equal     
bulk4#bi    ,nearly the same results    
were obtained in the case of urine2 it  
underwent  no radical change2 its colour
 merely assumed a reddish brown tint2 it
  formed some small deposits of         
crystals1 but without becoming at all   
turbid or putrefying in any way4 ,the   
direct oxidation of the urinary         
substances was likewise very sluggish4  
,an analysis of the air in one of  the  
flasks1 made forty days after the       
commencement of the experiment1  gave   
the following results3--                
,oxygen                 #aib            
,carbonic acid           #jh            
,nitrogen               #hjj            

-----                                   
#ajjj    ,these experiments on blood and
 urine which we have just mentioned date
  from #ahfc4cj ,ten years afterwards1  
in #ahgc1 they were confirmed in an     
important and striking manner by the    
results of a very able series of        
experiments1 which were carried out in  
our laboratory1 by ,m4 ,gayon1 who  was 
formerly a pupil in the cole ,normale   
,suprieure4 ,m4 ,gayon proved  that what
 held good in the case of blood and     
urine1 also held good in  the case of   
the substances contained in eggs4 ,he   
found that the whites  of eggs might be 
exposed for any length of time to       
contact with air1 as  also might the    
yolks1 or the white and yolks mixed1    
without any  putrefactive change or     
fermentation resulting1 and without the 
smallest  microscopic germ showing      
itself1 the sole condition being that   
the air  must be freed from all organic 
particles of dust1 germs of mould1      
bacteria1 vibrios1 and other organisms  

which it holds in suspension4  ,this was
 only a part of the important facts     
brought to light by ,m4  ,gayon4        
,amongst other things1 he proved that   
spontaneous putrefaction in  eggs is    
invariably caused by the development of 
organized ferments1  thereby correcting 
the opposite statements announced by ,m4
 ,donn and ,m4  ,bchamp1 who were led by
 their observations to believe that the 
change  in eggs took place quite        
independently of the action of vibrios  
and  mucedines4#ca    ,it is almost     
superfluous to remark how greatly the   
results of these  experiments on blood1 
urine1 and the components of the egg are
 opposed  to the doctrine of spontaneous
 generation1 as also to most modern     
theories on the generation of ferments4 
,as long as experiments relating  to the
 question of so-called spontaneous      
generation were made on  heated         
substances1 the advocates of            
heterogenesis had some grounds for      
asserting that such materials could not 

satisfy the conditions of  spontaneous  
life1 and that we should obtain         
different results by using  natural     
organic liquids1 which1 if exposed to   
contact of pure air would  doubtless    
serve for the production of new beings  
which did not issue  from parents which 
resembled them4 ,this novel enunciation 
of the  hypothesis of spontaneous       
generation1 the only one1 we think1 that
 could  be defended after the           
publication of our ,memoir1 in #ahfb1 is
 condemned  by the preceding facts4     
,the same facts completely upset the    
hypothesis recently maintained by       
,messrs4 ,fremy and ,trcul on the       
subject of the causes of fermentation4  
8,side by side with the immediate1      
definite principles which may be  formed
 by synthesis10 says ,m4 ,fremy1 8such  
as glucose1 oxalic acid1 and  urea1     
other substances of greatly inferior    
stability exist1 the  constitution of   
which is considerably more complicated1 
containing all  the elements of living  

organs1 such as carbon1 hydrogen1       
oxygen1  nitrogen1 and even phosphorus  
and sulphur2 and often salts of lime and
  of the alkalies besides4 ,these bodies
 are albumen1 fibrin1 casein1 the       
congeners of vitellin and others4       
,chemical synthesis cannot reproduce    
them4 ,it is impossible1 in my opinion1 
to regard them as immediate1  definite  
principles4 ,i designate them by the    
general name of  semi-organized bodies1 
because they hold an intermediate place 
between  the immediate principle and the
 organized tissue4    8,these           
semi-organized bodies1 which contain all
 the elements of organs1  have the      
power1 like a dry seed-grain1 of        
existing in a state of organic          
immobility1 and of becoming active under
 circumstances which favour  organic    
development4 ,by reason of the vital    
energy that they possess  they undergo a
 succession of decompositions1 giving   
origin to new  derivatives1 and to the  
advent of ferments1 not by any process  

of  spontaneous generation1 but by a    
vital energy1 which pre-exists in  the  
semi-organized bodies1 and is simply    
carried on1 when this energy  manifests 
itself1 in these most varied organic    
changes40    ,after having expressed    
these hypothetical and confused         
opinions1 ,m4  ,fremy continues3--8,i do
 not consider1 then1 that these         
semi-organized  bodies serve merely as  
nourishment for certain animal and      
vegetable  organisms1 which may be the  
sole agents of fermentations1 but ,i    
give  them a direct rle and admit that1 
under the influences which ,i have      
already cited#cb they may assume a real 
and complete organization1 and  produce 
ferments which are not derived1 as we   
have seen1 from a germ or  an ovum but  
from a semi-organized body1 the vital   
energy of which has  become active4#cc  
,it will be seen that these opinions are
 quite  different from those which ,m4  
,pasteur has maintained in his works1   
since  they attribute the origin of     

alcoholic and lactic ferments to an     
albuminous substance4 ,taking the case  
of alcoholic fermentation alone1 ,i     
assert that1 in the production of wine1 
it is the juice of the grape  itself    
which1 in contact with air1 produces    
grains of yeast1 by the  transformation 
of the albuminous substances4 ,m4       
,pasteur1 on the  contrary1 maintains   
that the grains of yeast are produced by
 certain  germs40#cd    ,we have        
combated these propositions1 so         
extraordinary and unsupported by  any   
rigorous experiments1 before the        
,academy of ,sciences1 where they  were 
first enunciated4 ,on that occasion we  
related the facts in  connection with   
blood and urine1 which we have just     
discussed4 ,could  there be any more    
forcible argument against the theory of 
our honourable  colleague than those    
facts8 ,here we had natural albuminous  
substances1  forming part of matter     
eminently liable to putrefactive change 
and  fermentation1 which produced no    

ferments of any sort whatsoever when    
brought into contact with air deprived  
of its organic particles of dust4       
,under no known circumstances is        
albuminous matter transformed into      
grains of yeast or any other organized  
ferment1 and1 to our thinking1  nothing 
can be more chimerical than the         
gratuitous hypothesis of  hemi-organism4
    ,we shall proceed to new proofs of  
this1 dealing this time with a liquid   
formed by the life of a vegetable4      
,,iii4--,experiments on the ,juice      
contained in ,grapes4      ,in the      
course of the discussion which took     
place1 at the ,academy1 on the  subject 
of the generation of ferments1 properly 
so called1 much was said  about the     
oldest known fermentation1 that of wine4
 ,we at once resolved  to demolish ,m4  
,fremy's theory1 by a decisive          
experiment on the juice of  grapes4     
,illustration3 ,fig4 #h4    ,we prepared
 forty flasks1 capable of holding from  
#bej c4c4 to #cjj c4c4  7from #i to #aa 

fl4 oz47 and shaped as represented in   
,fig4 #h4 ,these we  filled with        
filtered must1 which was perfectly      
bright1 and which1 like  all acid       
liquids1 would remain sound1 after      
having been boiled for a few  seconds1  
although the ends of the long curved    
necks of the flasks  containing the must
 might remain constantly open for months
 or years4    ,we washed1 in a few cubic
 centimetres of water1 part of a bunch  
of  grapes1 washing the grapes          
separately1 or the grapes and the wood  
together1 or even the wood of the bunch 
alone4 ,this washing was easily         
accomplished by means of a perfectly    
clean badger's-hair brush1 the  water   
receiving all the particles of dust     
adhering to the surface of the  grapes  
and the wood of the bunch4 ,by means of 
a microscope we easily  proved that this
 water held in suspension an infinite   
number of  organized corpuscles1 some of
 them bearing a very close resemblance  
to  the spores of fungoid growths1      

others to alcoholic ferment1 others to  
mycoderma vini1 and so on4#ce           
,illustration3 ,fig4 #i4    ,we next    
proceeded to put on one side ten of our 
forty flasks1 to serve  for subsequent  
corroboration2 in ten others1 by means  
of the tube which  is represented on the
 right hand side of the flask 7,fig4    
#h71 we put a  few drops of the water in
 which the bunch of grapes had been     
washed2 in  a third series of ten flasks
 we put a few drops of the same liquid1 
after having previously boiled it4      
,lastly1 we introduced into the ten     
remaining flasks a drop of grape-juice1 
taken from the inside of an  uninjured  
grape4 ,to do this we had to bend the   
right-hand tube of each  of our last ten
 flasks1 drawing it out to a fine point 
and closing it in  the flame1 as        
represented in ,fig4 #i ,a4 ,this fine  
closed point was filed  round near its  
extremity and then thrust1 as           
represented in ,fig4 #i ,b1  into a     
grape placed on a hard substance2 when  

the point b was felt to  touch the      
substance supporting the grape it was   
broken off by a slight  pressure        
sideways at the point a1 where the file 
marks had been made4  ,we had taken care
 to secure a slight vacuum in the flask 
beforehand2  this now caused a drop of  
the juice to be drawn into the flask4   
,we then  drew out the fine point1 and  
closed it immediately in the flame of a 
spirit lamp4 ,the vacuum was produced by
 heating the flasks in our hands1  or   
over the flame of a lamp1 thus causing a
 little air to be forced out  through   
the end of the bent tube1 which we then 
closed up with the lamp4  ,when the     
flask was cool1 the slight difference of
 pressure sufficed to  force into it    
some of the juice contained in the      
grape1 as we have just  described4 ,the 
drop of juice that is sucked into the   
flask generally  remains in the curved  
part of the fine tube2 to mix it with   
the must we  must incline the flask so  
as to bring the must in contact with the

 drop2  after that we may replace the   
flask in its natural position4    ,the  
following are the results presented by  
our four series of  comparative         
experiments in the different cases4 ,the
 first ten flasks--our  standard flasks1
 containing must boiled in contact with 
pure air--showed  no signs of organized 
products2 the must might have remained  
in them for  any number of years without
 change4 ,our second series of flasks1  
which  contained the water in which the 
grapes1 separately and in bunch1 had    
been washed1 had undergone alcoholic    
fermentation in every instance2  this   
had manifested itself in all the flasks 
in the course of about  forty-eight     
hours1 the temperature being at about   
summer heat4 ,at the  same time that the
 yeast made its appearance in the form  
of little white  lines1 which gradually 
joining together formed a deposit on the
 sides of  the flask1 we perceived      
minute flakes of mycelium forming2      
sometimes  as a single fungoid growth1  

sometimes combined with another1 or with
  many together--these growths being    
quite independent otherwise of the      
yeast or alcoholic ferment4 ,in several 
cases1 too1 mycoderma vini  showed      
itself on the surface of the liquid in  
the course of a few days4  ,vibrios and 
lactic ferments1 properly so called1    
could not make their  appearance1 on    
account of the nature of the liquid4    
,the flasks of our third series1        
containing the water in which the bunch 
of grapes had been washed1 and which we 
boiled before our experiment1  remained 
as free from change as the flasks of our
 first series had done4    ,lastly1 our 
fourth series of flasks1 containing the 
drops of juice taken  from inside the   
grapes1 remained equally free from      
change1 although we  could not be       
certain of having removed1 in every     
case1 without  exception1 all causes of 
error which must inevitably occur       
sometimes in  so delicate an experiment4
    ,these experiments cannot leave the 

least doubt on our minds3    ,that must1
 if boiled1 will never ferment when in  
contact with air that  has been freed   
from the germs which exist in it in a   
state of  suspension4    ,that must may 
be fermented1 after boiling1 by         
introducing into it a very  small       
quantity of water1 in which a bunch of  
grapes has been washed4    ,that must   
will not ferment if we introduce into it
 some of this same  water which has been
 boiled and afterwards cooled4    ,that 
must will not ferment if we introduce   
into it a small quantity of  the juice  
contained in a grape4#cf    ,it follows1
 then1 that the ferment which causes    
grapes to ferment in the  vintage tub   
must come from the exterior1 and not the
 interior of the  grapes4 ,thus1 the    
hypothesis of ,,mm4 ,trcul and ,fremy1  
according to which  albuminous          
substances transform themselves into    
grains of yeast by the  action of a     
peculiar vital force1 is annihilated2   
fortiori1 there  can no longer be a     

question concerning ,liebig's theory1 on
 the  transformation of albuminous      
substances into ferments1 by a process  
of  oxidation4    ,our readers may be   
curious to know what ,m4 ,fremy has been
 able to oppose  to such crucial        
experiments2 they could scarcely have   
imagined the  following3--    8,in my   
experiments1 which ,i have varied in    
every possible manner10 says  that      
gentleman1 8,i have found that it is    
almost impossible to discover  alcoholic
 fermentation1 appreciable by its       
results1 in a single drop of  grape     
juice1 and ,i may add that this         
fermentation must be still more         
difficult to discover when this drop has
 been drowned in a large  quantity of   
juice that has been previously          
boiled40#cg    ,it will be admitted that
 we were justified in saying1 at the    
commencement of this paragraph1 that we 
should demolish the theory which  was   
opposed to ours1 and which its advocates
 have been constrained to  defend by    

hypotheses manifestly false4    ,at the 
meeting following the one in which ,m4  
,fremy declared that minute  quantities 
do not ferment1 we had the malicious    
satisfaction of showing  a great many   
very small closed flasks1 into each of  
which we had caused  a single drop of   
the must of crushed grapes to be        
introduced by suction4  ,we broke the   
thin points of many of them1 in the     
presence of the  ,academy1 and every one
 of them showed by a sharp hissing1     
which was  audible at a distance1 that  
fermentation was proceeding in the drop 
of  liquid they contained4 ,m4 ,fremy   
was there1 but he made no remark4    ,we
 may cite some very curious facts on the
 subject of the period at  which the    
germs that develop yeast are in a       
condition to be able to  cause          
fermentation4    ,on ,july #beth1 #ahge1
 in the neighbourhood of ,arbois        
7,jura71 the grapes  were still green   
and of the size of peas4 ,we went to a  
vine that was far  from paths and roads1

 and there1 with a pair of small        
scissors1 cut some  grapes from off a   
bunch and let them fall with their short
 stalks into  tubes half filled with    
gooseberry must1 previously rendered    
unalterable  by boiling4 ,these tubes we
 closed again with all possible         
precautions1  using corks which had been
 passed through the flame of a          
spirit-lamp and  carried them to our    
laboratory1 where we left them to       
themselves4 ,some  days afterwards we   
saw diverse fungoid growths appear in   
most of the  tubes1 but not one of them 
then1 or subsequently1 presented the    
least  appearance of fermentation4 ,the 
germs of yeast at that period of the    
year did not exist either upon the woody
 part of the bunch1 or upon the  grapes4
 ,in ,chapter ,v4 we shall return to    
observations on this subject4           
,,iv4--,wort and ,must ,exposed to      
,common ,air4      ,if the principles   
which we have laid down possess all the 
value that we  attribute to them1 if the

 cause of change in natural or          
artificial  organic liquids does not    
exist in those liquids themselves1 if   
change  considered in itself depends    
upon the nature and number of the       
particles  of dust in various places1 if
 it is1 besides1 radically affected by  
the  composition of the liquids1 it must
 necessarily follow that wort or  must1 
whilst1 under certain circumstances of  
exposure to air1 it remains  absolutely 
free from life and its results1 will1   
under other  circumstances1 give rise to
 a variety of organisms and their       
corresponding fermentations4 ,this is1  
in fact1 the lesson which direct  proofs
 will teach us4 ,before entering upon   
these new observations in  detail1 we   
must call the reader's attention to the 
difficulty1 as  experience has shown1 of
 interpreting correctly the facts       
connected with  the spontaneous         
impregnations of organic liquids4       
,gay-,lussac crushed some grapes under a
 bell-jar filled with mercury1  after   

having washed them in hydrogen1 to expel
 the air adhering to the  grapes and the
 sides of the jar4 ,having waited for   
several weeks without  detecting any    
signs of fermentation1 he introduced    
some bubbles of  oxygen1 and            
fermentation showed itself the following
 day4 ,gay-,lussac  concluded that the  
fermentation of must could not commence 
without the  help of oxygen4#ch         
,under the conditions of his experiment 
nothing could be truer1 and we  must    
admire the diffidence with which this   
great natural philosopher  interpreted  
the fact that he had observed4 ,another 
,french natural  philosopher1 however1  
,m4 ,cagniard-,latour1 observed that the
 ferment of  alcoholic fermentation was 
a little cellular plant4 ,what was its  
origin  in ,gay-,lussac's experiment8   
,the advocates of the doctrine of       
spontaneous generation were ready with  
their explanation1 and we have seen how 
,,mm4 ,trcul and ,fremy1 following  many
 others1 did not hesitate to maintain   

that the little plant with all  its     
particles was produced by the action of 
oxygen on the albuminous  substances    
contained in the juice of the grapes4   
,the experiments1 which  we have given  
in the preceding paragraph1 show us     
positively that germs  of the ferment of
 must exist on the surface of the grape1
 and that1  consequently1 ,gay-,lussac's
 experiment has a more simple and       
natural  explanation4 ,the germs of the 
ferment existing on the surface of the  
grape become mixed with the juice of the
 grape when the latter is  crushed2     
these germs remain inactive in the      
presence of hydrogen2 they  vegetate as 
soon as oxygen is introduced to them4   
,moreover1 the results of our labours in
 connection with spontaneous            
generation1 in #ahfb1 teach us that in  
,gay-,lussac's experiment the germ  of  
the ferment might also have had its     
origin either in certain  particles of  
dust adhering to the sides of the glass 
bell1 or upon the  mercury2 and1 in a   

laboratory where alcoholic fermentation 
is studied1  dust invariably contains   
dry cells of ferment4 ,the necessity of 
oxygen  for the success of the          
experiment is surprising1 when we       
reflect that  alcoholic fermentation    
often takes place in liquids that are   
not exposed  to contact with air2 but we
 shall prove by experiment that1        
notwithstanding what may happen during  
fermentation1 oxygen has the  greatest  
influence on the readiness with which   
ferment develops itself1  and that this 
gas is indispensable to the revival of  
withered cells1 and  still more so to   
the germination of special cells1 which 
we may consider  to be the true germs of
 the little plant4    ,the advocates of 
the doctrine of spontaneous generation  
have based  most of the objections which
 they vainly urge against their         
opponents  upon erroneous               
interpretations of certain facts        
relating to the  spontaneous            
impregnation of organic infusions4      

,taking a very wrong view  of the       
essential conditions of the phenomena1  
they require that the  assertors of the 
diffusion of the germs of microscopic   
organisms should  be compelled to place 
at any one point of space1 so to say1   
all the  germs of the products of       
infusions2 a demand which really borders
 on  absurdity4 ,they believe1 or feign 
to believe1 that we are bound to admit  
the existence of germs of must in all   
places and at all times1 on the  banks  
of rivers and on the loftiest mountains1
 and so on4  8,fermentations10 said one 
of these gentlemen one day1 before the  
,academy1 8cannot depend upon chance    
particles of atmospheric dust4 ,how  is 
it possible that germs of yeast can be  
present everywhere throughout  the      
universe1 ever ready to fall upon must80
 ,it is an established fact  that grapes
 crushed in any part of the globe       
whatsoever1 even on a  glacier or at the
 highest elevations1 can set up a       
fermentation4 ,the  explanation of this 

pretended impossibility is most simple1 
for we know1  from the facts related in 
the preceding paragraph1 that grapes    
carry on  their skins the germs of their
 own ferments4    ,in experiments       
relating to the kind of organisms which 
we are discussing  we must never fail to
 take into account the action of the    
particles of  dust spread over the      
articles that are used4 ,very often an  
effect that  should be attributed to    
germs adhering to the vessels and       
utensils used  in experiments1 the      
origin of which may be altogether       
special1 is  erroneously imputed to the 
dust-forming germs--that is to say1 to  
those  germs which exist in a state of  
suspension in the air4    ,in our       
,memoir of #ahfb1 which we have quoted  
several times1 we have  explained that  
it is almost impossible to draw any     
serious conclusions  from experiments   
made in a basin of mercury1 because of  
the organic  particles of dust which    
always exist in that metal1 and which1  

without  the knowledge of the operator1 
pass into the interior of the vessel1   
where they produce certain changes which
 one is tempted to impute to            
heterogenesis4    ,in all classical     
works an experiment of ,appert's1       
reproduced by  ,gay-,lussac1 is given4  
,this1 through a faulty interpretation1 
led to the  hypothesis of the continuity
 of the causes of fermentation1 if we   
may  use such a term1 in the atmospheric
 air4#ci    ,when we decant bottles of  
must1 which has been preserved by       
,appert's  method1 into other bottles1  
all the latter soon set up a            
fermentation3  this constitutes the     
experiment4 ,if it were proved that the 
must1 whilst  being decanted1 came in   
contact with atmospheric air alone1 as  
,gay-,lussac believed1 we should be     
compelled to admit1 according to the    
theory of germs1 that the must had come 
in contact with some particles  of      
ferment in the air during decanting4    
,and again1 if it were shown that  the  

experiment could succeed in any place   
whatsoever1 we must come to  the        
conclusion that germs of ferment exist  
everywhere in a state of  suspension in 
the air4    8,i have taken10 writes     
,gay-,lussac1 8a bottle of must that had
 been  preserved for a year and was     
perfectly transparent1 and have decanted
  the must into another bottle1 which ,i
 then carefully corked and exposed  to a
 temperature of #ae ,c4 to #cj ,c4 7#ei 
,f4 to #hf ,f474 ,eight days  afterwards
 the must has lost its transparency2    
fermentation has taken  place in it1 and
 soon my must has become transformed    
into a vinous  liquor1 sparkling like   
the best champagne4 ,a second bottle of 
must that  had been preserved for a     
year1 like the preceding one1 but which 
had not  been brought into contact with 
the air1 has presented no signs of      
fermentation1 although placed under     
conditions most favourable to its       
development40    ,the result of this    
experiment1 when roughly made1 is       

correctly described  by ,gay-,lussac2 in
 other words1 it may be proved that if1 
at the time of  vintage1 we prepare some
 bottles of must1 after ,appert's       
process1 and1  in the course of time1   
open them and decant their contents into
 other  bottles1 we shall soon see the  
must ferment and deposit yeast4 ,it is1 
nevertheless1 equally certain that the  
inferences which have been drawn  from  
this celebrated experiment have been    
founded on error1 and that the  germs of
 yeast are very rarely derived from the 
particles of dust  floating in the air  
with which the must comes in contact4   
,the germs in  question are1 in our     
opinion1 generally derived1 not from the
 air1 but  from the sides of the        
bottles1 from corks1 from the string    
employed in  corking1 from corkscrews1  
and from a variety of other things4 ,the
 reason  for this is that any room1     
vault1 cellar1 or laboratory where the  
grapes1 or must1 or vintage1 are        
handled--unless special precautions1 of 

which ,appert and ,gay-,lussac certainly
 never thought1 are taken--all the      
utensils1 as well as all articles of    
clothing1 and all the sides of the      
bottles which the hands have touched1   
are contaminated by cells of  ferment   
derived from must that has fermented1 or
 by germs from the  surface of grapes   
and clusters4 ,thus1 at the moment of   
decanting the  must1 a thousand         
accidental circumstances may lead to the
 introduction  of those germs1 the      
origin of which1 as we have seen1 may be
 actually  traced to the very grapes    
which served for the manufacture of the 
must4  ,in other words1 we believe the  
inference that the germs of yeast which 
cause the experiment to succeed1 are    
derived from particles of dust  floating
 in the air of the place where we decant
 the contents of our  bottles1 to be    
altogether an erroneous one4    ,since  
the preceding remarks were written1 we  
have endeavoured to repeat  this        
experiment of ,gay-,lussac's in such a  

manner as we believed would  confirm our
 views1 by varying the conditions in    
such a way as would  cause it to succeed
 or fail1 according to the circumstances
 of the  manipulation employed4    ,on  
,december #gth1 #ahgd1 we took two      
bottles of must which we had  preserved1
 after ,appert's process1 in our        
laboratory from the beginning  of       
,october1 #ahgc4 ,both of these were    
covered with dust--the dust that        
floated about in our laboratory4 ,we    
decanted them as follows3--,one  bottle1
 which we handled without special       
precautions1 we uncorked by  means of an
 ordinary corkscrew1 and decanted into  
another bottle that  had been well      
washed1 as bottles are washed when they 
are to be used  subsequently4 ,this     
bottle was taken from a number that had 
been standing  upside down on a drainer 
for a fortnight4 ,we took no precaution 
to  remove the dust which covered the   
exterior of the bottle of must1 or to   
purify the washed bottle4 ,the second   

bottle of must1 on the other hand1  was 
decanted after we had removed the dust  
that covered it2 its cork was  cut off  
close to the string1 and the flame of a 
spirit lamp was passed  over the string 
and the surface of the cork2 and1 as a  
final precaution1  the corkscrew was    
passed through the flame4 ,as for the   
bottle into which  we subsequently      
decanted the must1 we first plunged it  
in a hot-water  bath kept at #ajj ,c4   
7#bab ,f471 then took it into a garden  
to cool  upside down in the open air4   
,after these precautions we removed it1 
and  immediately decanted into it the   
must from the second bottle4    ,the    
first bottle showed signs of growths1   
both on the surface and at the  bottom  
of the must1 the day after the          
operation1 and manifested the  first    
symptoms of alcoholic fermentation on   
,december #afth4 ,the contents  of the  
second bottle remained perfectly        
unchanged after being exposed to  the   
warmth of a stove for several months4   

,can anything be more conclusive than   
these facts8 ,they are in perfect       
keeping with the views that we have     
recently expressed1 and with the        
principles that we have maintained for  
nearly twenty years1 on the  subject of 
the causes of change in organic liquids4
    ,it is by no means our intention to 
assert that in the atmospheric air      
there exist no germs of ferment in a    
state of suspension1 as fine dust4      
,beyond all doubt they do so exist in   
that state2 but1 as a rule1 in          
comparatively small number1 their       
abundance or scarcity being dependent   
upon circumstances which control their  
multiplication1 favouring or            
restricting it1 as we are about to      
prove4    ,on ,may #bnd1 #ahgc1 we      
uncorked two ordinary bottles filled    
with wort1  prepared in ,december1      
#ahgb1 after ,appert's process4 ,to     
avoid the causes  of error which we have
 mentioned1 we uncorked the bottles in  
the  following manner3--,the cork was   

cut off to the level of the neck2 the   
cork and string were next passed through
 flame1 regardless of burning  and      
charring them2 we then gently extracted 
the cork by means of a  corkscrew which 
also had been passed through the flame4 
,the bottles thus prepared were placed  
on the table of an underground  room1 in
 which we were continually making       
experiments on alcoholic  fermentation4 
#ast bottle4--,on ,may #gth we observed 
little particles of fungoid growth  on  
the surface of the liquid1 and at the   
bottom were large flakes of  mycelium4  
,on ,may #aath a veil of mycoderma vini 
had formed3 there were no signs  of     
fermentation4    ,on ,may #acth vigorous
 fermentation commenced2 it lasted until
 ,may #bcrd4  ,the microscope revealed  
yeast in globules of two sizes1 the     
larger of  which were considerably less 
numerous than the others4 ,there were no
  signs of lactic or butyric ferment4   
#bnd bottle4--,may #gth1 particles of   
fungoid growth on the surface of the    

liquid1 and also a veil of mycoderma    
vini4 ,on ,may #aath1 #acth1 and up  to 
the #bcrd1 no signs of fermentation were
 visible4 ,on ,may #cjth  fermentation  
was active4 ,the microscope showed us   
yeast mixed with  butyric vibrios4      
,in this case1 alcoholic ferments had   
come into existence1 and from the       
precautions taken at the moment when the
 liquid was brought into contact  with  
the external air1 it is certain that the
 advent of the germs of  those ferments1
 as also those of the other organisms   
which made their  appearance--the       
fungoid growths1 mycoderma vini and     
vibrios--could  only be accounted for by
 the fall of particles of dust floating 
about in  the room4 ,it follows1 then1  
that under certain circumstances germs  
of  alcoholic ferment may be found      
floating in the air2 but we can readily 
show that the peculiar conditions of the
 place had a large share in  bringing   
about the results obtained by the       
foregoing experiment4    ,the same day1 

,may #bnd1 #ahgc1 we uncorked1 with the 
precautions that we  have already       
described1 four other bottles of the    
same must4 ,these were  placed in a room
 which was used less frequently than the
 preceding one1  and in which           
experiments relating to fermentation    
were seldom conducted4    #ast          
bottle4--,on ,may #hth we observed on   
the surface of the liquid large1  frothy
 pieces of mycelium 7mucor mucedo or    
mucor racemosus74 ,the  liquid was      
perfectly bright4#dj    ,may #cjth4--,no
 signs of actual fermentation yet       
visible4    #bnd bottle4--,on ,may #hth 
we noticed a thin1 greasy-looking scum  
on our  liquid1 which had become turbid 
and acquired a sour smell4 ,the         
microscope showed that this scum was    
formed of mycoderma aceti4 ,on ,may     
#cjth the scum had assumed a whitish    
appearance1 and seemed to be dead2      
there was a green spot of penicillium   
glaucum upon it4 ,no signs of           
fermentation4    #crd bottle4--,may     

#hth1 patches of fungoid growth on the  
surface of the  liquid4 ,may #cjth1     
thick and abundant fungoid growth1 but  
no  fermentation4    #dth bottle4--,may 
#hth1 little patches of fungoid growth1 
and a scum of  mycoderma vini4 ,may     
#cjth1 still no fermentation4    ,up to 
the month of ,august1 #ahgc1 not one of 
these bottles gave the least  sign of   
alcoholic or other fermentation4    ,on 
,december #afth1 #ahgb1 we uncorked four
 bottles of wort1 which also had  been  
preserved by ,appert's process2 these we
 placed on an oven1 where  there were   
always vessels fermenting1 at about #be 
,c4 7#gg ,f471 but  where none of the   
manipulations required for the starting 
or final study  of fermentations were   
practised4 ,the next day a fungoid      
growth1 but  unaccompanied by any signs 
of fermentation1 made its appearance1   
and  this state of things lasted for    
five months1 after which we ceased to   
keep these bottles under observation4   
,on ,may #bfth1 #ahgc1 we uncorked1 with

 all the necessary precautions1 ten     
bottles of wort1 which had been         
preserved from ,april #ith1 and then    
left  them undisturbed in a room where  
we were constantly engaged in the study 
of fermentation4    ,on the following   
day1 some patches of fungoid growth     
appeared on the  surface of the liquids4
    ,may #cjth4--,fermentation commenced
 in one of the bottles4    ,may         
#cast4--,a second bottle likewise began 
to ferment4    ,june #ith4--,four       
bottles1 including the two preceding    
ones1 were now in a  state of           
fermentation4 ,the six bottles that had 
not fermented were  thereupon covered   
with caps of paper1 taken from the      
centre of a ream of  paper and passed   
through a flame4 ,after this1 and up to 
,august #a1 when  our observations were 
discontinued1 these six bottles         
underwent no  fermentation4    ,from    
these examples1 which are confirmed by  
many others that we shall  have occasion
 to mention in the course of this work1 

it will be seen  that the germs of      
alcoholic ferment are not present in    
every little  point of space1 constantly
 ready to fall upon any object1 not even
 in  those places where one is          
perpetually dealing with that kind of   
growth4#da ,if we conduct our           
experiments with exactness1 we very soon
  learn that all that has been written  
on the facility with which  saccharine  
musts may be made to ferment1 by being  
rapidly brought into  contact with the  
surrounding air1 is greatly exaggerated4
    ,the germs of ferments1 especially  
of alcoholic ferments--the yeast of     
beer and the yeast of wine--are not     
nearly as abundant in atmospheric  air1 
or in the particles of dust spread over 
the surface of things1 as  are the      
spores of fungoid growths4 ,it is easy  
to understand this1 for  spores are     
generally borne by aerial organs in a   
state of dryness1 so  that the least    
breath of wind catches them up and      
carries them away1  whilst ferments are 

composed of moist cellules that do not  
readily  become dry4    ,the vacuous    
flasks1 partly filled with organic      
liquids1 which are opened  and closed   
again immediately1 frequently give us   
fungoid growths1 but  very rarely       
alcoholic fermentation1 although in the 
latter respect they  may not be         
absolutely sterile4 ,we may cite some   
proofs of this4    ,on ,june #aith1     
#ahgb1 we prepared seven flasks of      
saccharine liquid1  impregnated with    
yeast--our flasks were of #cjj c4c4     
capacity 7about #aj  fl4 oz47--and      
contained #ajj c4c4 of the liquid2 we   
then drew out their  necks to a small   
opening1 which was sealed during        
boiling1 after the  steam had expelled  
all the air4    ,on ,june #bith we      
opened them in the principal room of our
 laboratory4    ,on ,july #ith1 two of  
the seven flasks gave no sign of        
organized products2  the others were    
swarming with mycelia1 submerged or     
fruiting on the  surface of the liquid1 

and either with or without bacteria     
entangled  in their flakes4 ,in two of  
the flasks there were visible at the    
bottom  of the liquid some white        
streaks1 which is an indication         
sometimes of  the presence of alcoholic 
ferment1 but much more frequently of a  
little  cellular plant resembling it in 
appearance1 but purely aerial in its    
growth1 that is to say1 taking no part  
in fermentation4 ,some days  afterward1 
we saw bubbles of gas rising from the   
bottom of one of these  flasks1 and then
 fermentation proceeded so rapidly that 
we were obliged  to open the neck to    
avoid an explosion4 ,we append a sketch 
of its  ferment 7,fig4 #aj74            
,illustration3 ,fig4 #aj4    ,the other 
flask with the white streaks showed no  
signs of any  fermentation4    ,in this 
kind of observation we rarely succeed in
 obtaining active  ferments1 the reason 
being that we deal with volumes of air  
that are too  limited for the few germs 
of ferment that exist in a state of     

suspension  in it4    ,we are more sure 
of success if we expose a tolerably     
large surface of  saccharine liquid to  
the open air1 because1 under such       
circumstances1  even if the exposure is 
of short duration1 a considerable volume
 of air  will pass over the surface of  
the liquid4    ,on ,may #bith1 #ahgc1 at
 five o'clock in the afternoon1 we      
placed in the  underground room         
previously mentioned1 at a height of    
about two feet1  ten porcelain dishes   
having surfaces of from thirty-five to  
forty square  inches4 ,we had just taken
 them from boiling water1 and after     
allowing  them to cool we placed in each
 quantities of wort to about one-third  
of  an inch deep1 which we poured from  
bottles uncorked with every  precaution 
against the chance of the wort coming   
into contact with  anything besides the 
floating particles of dust4 ,on ,may    
#cjth1 at five  o'clock1 that is after  
twenty-four hours of exposure to the air
 of the  room1 we emptied the contents  

of the basins separately into glass     
flasks  with long necks1 which had been 
treated with boiling water and then     
cooled1 necks downwards4 ,the beak of   
the basin1 by means of which the  liquid
 was poured1 and the funnels--for we    
used a separate funnel for  each        
flask--had been passed through the      
flame4 ,the whole ten flasks were  then 
placed in an oven at a temperature of   
#be ,c4 7#gg ,f474#db    ,on ,june #ast 
six of the flasks gave signs of         
fermentation1 and next day  all the     
flasks were fermenting4    ,the         
following are some of the numerous      
microscopic observations which we  made 
on the liquids and their deposits4      
,on ,june #ast the liquid in one of the 
six flasks which had begun to  ferment  
was covered with a continuous scum of   
mycoderma vini1 below  which appeared a 
filamentous network belonging to a      
mycelium1 or other  fungoid growth4 ,but
 neither in the liquid itself nor in the
 deposit  could we perceive any cells of

 the ferment of beer2 the field1        
however1  was swarming with active      
butyric vibrios1 rather thick and short1
  their length being about twice their  
diameter4 ,this fermentation was        
exclusively butyric4    ,on ,june #bnd  
another of the flasks showed no vibrios1
 but alcoholic  ferment in small        
quantity1 much lactic ferment1          
consisting of little  particles         
contracted at the middle and non-mobile1
 and1 finally1 some  slender filaments1 
resembling those represented in ,plate  
,i41 ,nos4 #a and  #b4    ,on ,june #crd
 we examined the liquid in the flask    
which showed the most  marked           
fermentation4 ,in addition to the flakes
 of fungoid growths1  checked in their  
development through want of air1 we     
found at least five  distinct           
productions1 which are represented in   
the accompanying sketch  7,fig4 #aa74   
aaa4--,thick cells of alcoholic ferment1
 the size of which is given      in our 
sketch3 thus1 #ac_/dej indicates that   

the corresponding figure      is        
#ac_/dej millimetre in length 7rather   
more than #a_/ajjj inch74               
bbb4--,small alcoholic ferment1 such as 
we generally see in the must      of    
acid and sugared fruits--especially in  
filtered grape must4 ,its               
dimensions varied from #a to #a-1 or #b1
 #dejths of a millimetre4#dc            
,illustration3 ,fig4 #aa4               
ccc4--8,low0 yeast1 of a type resembling
 that existing in other                 
preparations fermenting in the room4    
ddd4--,enlarged1 distended spores of    
mucor racemosus4 ,these are      scarce1
 and have an old appearance4 ,we shall  
come to them again in a      subsequent 
chapter1 where we shall explain their   
real significance4        eee4--,short  
vibrios1 occurring either contracted or 
not near the      middle4 ,some were    
motionless1 others vibrating to and fro 
and      executing other movements4     
,these forms belong to the butyric and  
lactic ferments shown on ,plate ,i4     

,the preceding series of experiments    
shows us that1 in the case of wort      
exposed to the air1 germs of divers     
organisms1 amongst which various        
ferments--butyric1 lactic1 and          
alcoholic--are to be found1 fall        
simultaneously from the particles of    
dust floating in the air4 ,we must      
observe1 however1 that we were dealing  
with the air of a laboratory in  which  
we were constantly studying analogous   
fermentations1 and that a  different    
atmosphere would1 most likely1 give us  
different results4 ,we  shall see a     
proof of this in the following          
paragraph1 where we shall  also find    
some new facts tending to prove that the
 germs of alcoholic  ferment do not     
exist amongst the particles of dust     
floating in the air1  in anything like  
the quantity usually supposed4          
,v4--,new ,comparative ,studies on the  
,germs held in ,suspension by the ,air  
of ,different ,places which are near    
each other1 but ,subjected to           

,different ,conditions affecting the    
,production and ,diffusion of the       
,particles of ,dust found in them4      
,we may compare the character and the   
greater or less abundance of  similar   
germs existing in neighbouring          
localities1 by studying the  changes    
which take place in similar liquids     
exposed simultaneously to  the action of
 the air in those localities4 ,to do    
this1 we must prepare a  large number of
 flasks of the same size1 free from air1
 and containing  about equal quantities 
of a particular liquid--the same being  
used for  all4 ,we must open the same   
number of these flasks in each of the   
localities we have selected1 and permit 
the air with all its particles  of dust 
to rush into them2 then we must close   
our flasks again1 and  observe1 day by  
day1 the appearances they present4 ,the 
results obtained  by these means will   
not furnish us with conclusions         
applicable to every  kind of germ that  
the air contains at any given moment1   

but only with  conclusions which apply  
to those germs which can develop in the 
particular liquid employed4 ,thus1 for  
example1 we could draw no  inference as 
to the nature and relative number of    
bacteria or  vibrios1 in the case where 
we employ an acid liquid2 for organisms 
of  that kind we must have recourse to  
neutral or slightly alkaline  infusions4
 ,on the other hand1 liquids having a   
feeble acid reaction  would favour the  
growth of mucedines1 mycoderms1 and     
certain  ferments1 as for example1 the  
alcoholic4    ,on ,november #bfth1      
#ahgb1 we opened and reclosed thirty    
flasks containing  must kept from the   
last vintage4    ,ten flasks were opened
 at the bottom of the garden of the cole
  ,normale4    ,ten on the landing of   
the second floor4    ,ten in the        
principal room of our laboratory1 which 
had been swept out  shortly before1 by  
which operation the dust of the floor   
had been raised  and put in motion4     
,different objects made their appearance

 in a certain number of the  thirty     
flasks on the following days2 but from  
,december #agth1 things  remained       
stationary4 ,the following observations 
were made at that date3--    ,of the ten
 flasks from the bottom of the garden1  
only one had undergone  any change4     
,of the ten flasks from the interior of 
the building1 four had undergone        
change4    ,of the ten flasks from our  
laboratory1 all had undergone change4   
,the difference in the number of germs  
held in suspension in the three         
different places whence we had taken our
 air was1 therefore1  considerable4     
,the difference in the nature of the    
germs was equally marked4 ,those  flasks
 of our first two series which had      
undergone change presented no  trace of 
torul1 or anything besides fungoid      
growths1 whilst three of  the last ten  
contained torul associated with fungoid 
growths4#dd    ,illustration3 ,plate #c4
 ,torul in ,process of ,development4    
,on ,may #bith1 #ahgc1 eighteen flasks1 

free from air and with necks drawn  out 
to a fine point1 containing must1 were  
taken into one of our rooms  at the cole
 ,normale4 ,a jet of gas from an        
ordinary burner was passed  over the    
surface of the glass down to the surface
 of the liquid1 with  the object of     
burning any particles of dust that might
 have been  deposited from the          
atmosphere of the laboratory2 the points
 of the  flasks were then broken with a 
pair of ordinary scissors that had been 
passed through the flame of a spirit    
lamp2 and1 lastly1 the tops of the      
flasks were taken off1 just above the   
surface of the liquid1 and the  eighteen
 flasks thus became transformed into    
eighteen basins1 each  containing about 
#ajj c4c4 7about #c- fluid ounces7 of   
grape must4 ,these  eighteen basins were
 placed on a table in the room1 and left
 there for  five days1 precautions being
 taken to prevent any one from entering 
the  room4    ,the basins were examined 
on ,june #bnd3 they all contained little

 flakes  of floating mycelium1 but none 
of them had any white streaks on their  
sides--a proof that they were destitute 
of torul--the liquid had  remained very 
bright4 ,with the contents of nine of   
the basins we filled  two long-necked   
flasks that we had prepared for our     
purpose--that is to  say1 had heated to 
a certain point1 just before using them1
 with the  object of removing from their
 sides any foreign germs which they     
might  have picked up in the laboratory4
 ,up to ,july #ajth1 when we deemed it  
useless to carry our observations       
further1 these flasks presented no      
signs of fermentation whatever4 ,with   
the contents of the remaining nine      
basins1 we filled two other long-necked 
flasks1 but before doing so1 we  kept   
the basins for twenty-four hours 7,june 
#bnd to #crd7 in the basement  of our   
laboratory4 ,these two flasks soon set  
up an active fermentation1  and         
deposited an abundance of yeast--an     
additional proof of the great           

difference in character of the germs    
floating about the room and those       
floating about the laboratory4    ,on   
,june #crd we exposed1 simultaneously1  
in the aforementioned room and  also in 
our laboratory1 seven basins prepared as
 just described4 ,on ,june  #hth all the
 basins in the room showed signs of     
fungoid growths1 without  any trace of  
mycoderma vini1 or lines indicative of  
the presence of  torul1 whilst six of   
the seven in our laboratory had their   
sides  covered with a white precipitate1
 and on the surface of the liquids a    
layer of isolated patches of fungoid    
growth4 ,the liquid in these latter     
basins was poured into a long-necked    
flask1 which it nearly filled1 and  in  
the course of forty-eight hours it began
 to show signs of alcoholic             
fermentation4#de ,this is another       
striking proof of the difference        
between the number of germs of ferment  
and torulace in the air of our          
laboratory and that of an ordinary room4

    ,illustration3 ,fig4 #ab4    ,we    
append drawings of the torul found in   
the six laboratory basins  7see         
,sketches ,i41 ,,ii41 ,,iii41 ,,iv41    
,v41 ,,vi4 of ,fig4 #ab74 ,the abundance
 of  the germs of these organisms in our
 laboratory is very striking1 and is    
doubtless due to the nature of the work 
carried on there1 as well as to  the    
power of endurance peculiar to the      
germs1 or the minute vegetative  cells  
of these microscopic plants--a tenacity 
of life which prevents them  from losing
 their reproductive powers1 even after  
being dried up into  dust4 ,but varied  
as are the formations represented in    
,fig4 #ab--;and it  will be observed    
that in ,,iv4 and ,,vi4 we have shown   
four distinct forms1  marked a1 a2 b1 b2
 m1 m2 n1 n respectively--it must not   
be supposed that they correspond        
necessarily to distinct species4 ,from  
the ends of a compound organism like    
those in ,no4 ,,iii1 a little  spherical
 cell may detach itself and then1 by a  

process of budding1 give  rise to a     
series of other minute spherical cells  
reproducing the form  shown in ,nos4 ,i4
 and ,,ii4    ,the forms figured in ,no4
 ,,iii4 represent one of the types of   
mycoderma  vini1 which is often found in
 this branching arborescent state2 but  
it  frequently also occurs in short     
forms1 and it is in this shape that it  
is generally met with on the surface of 
wines4    ,it is true that the nature of
 the substratum has a great influence on
  the changes of aspect in the organisms
 which we are describing1 but this  is  
not the sole cause of their             
morphological modifications4 ,we are    
strongly inclined to believe that each  
of the cells1 or vegetating forms  so   
represented1 differing so greatly as    
they do in aspect1 and begotten1  all of
 them1 spontaneously in certain         
appropriate liquids1 in a  laboratory   
where researches on fermentation are    
pursued1 is capable of  furnishing a    
distinct variety4 ,in fact1 there is not

 a single one of the  cells in the six  
varieties in ,fig4 #ab1 which1 taken    
alone1 has not its  own peculiar        
characteristics1 which1 by hereditary   
transmission1 it can  impart1 in a      
greater or less degree1 to all the      
individuals of the  generations that    
succeed it4    ,we may remark1 on the   
other hand1 that nothing can be more    
favourable to  the isolation of         
different varieties of torul or         
mycoderma vini  than the spontaneous    
impregnations to which we submit our    
liquids4 ,for  when suitable liquids    
contained in flasks exhausted of air are
  impregnated with the particles of     
atmospheric dust1 by opening the  flasks
 for a moment and then immediately      
re-sealing them1 it must  generally     
happen that we admit only one species of
 reproductive  organism1 so that we     
shall have a vegetation exclusively of  
one kind1 as  being derived from the    
same mother-cell4 ,if we could take from
 a crowd  composed of men and women     

separate couples1 and forthwith         
transport each  couple to a separate    
isolated and unpeopled island1 they     
would1 in the  course of time1 beyond   
doubt form so many distinct tribes4     
,it is very remarkable that some of the 
torul in ,fig4 #ab are not  ferments2   
they do not cause sugar to decompose    
into alcohol and carbonic  acid1 any    
more than the mycoderma vini does2 but1 
nevertheless1 there  may be an absolute 
similarity in aspect1 development1      
shape1 and size  between the alcoholic  
ferment1 properly so called1 and these  
torulace4    ,we must here cite a case  
in proof4 ,on ,may #bhth1 #ahgb1 in one 
of the  rooms of our laboratory1 we     
broke the fine points of a series of    
flasks1  similar to those used in our   
previous experiments1 containing must of
  grapes and deprived of air4 ,we then  
closed up the ends immediately after    
the sudden entrance of the exterior air4
 ,one of these flasks developed  only   
one kind of organism1 which belonged to 

the torulace4 ,on ,june  #gth this was  
sufficiently abundant to cover all the  
sides with a white  deposit1 and the    
surface of the liquid appeared quite    
free of any  mycoderma vini4 ,to assure 
ourselves that we were actually dealing 
with  one kind of torul1 unattended by  
fungoid growths1 we waited until  ,june 
#adth1 but the aspect of things remained
 unchanged4 ,on that day we  opened the 
flask2 there was no escape of gas to    
indicate that the  interior pressure was
 greater than the exterior4 ,we then    
subjected the  plant to microscopic     
examination4 ,it was quite homogeneous1 
and formed  of a mass of cells1         
absolutely identical in aspect and size 
with old  cells of ordinary yeast 7,fig4
 #ac74    ,illustration3 ,fig4 #ac4     
,we distilled all the liquid1 of which  
there was about #ajj c4c41 7#c- fl4     
oz47 without obtaining any trace of     
alcohol in our distillate2 we  collected
 #cc c4c4 7about an ounce7 of the       
distillate1 which we distilled  again1  

and we submitted the distillate a third 
time to distillation2 but  even then    
there were no more signs of the presence
 of alcohol than there  had been in our 
first distillate4#df    ,we may safely  
conclude that our torula1 in the course 
of its  development in must1 with a     
weight that would have been very        
appreciable1 did not produce1 by its    
action of multiplication #a_/aj1jjj  of 
#a c4c4 of alcohol4    ,under the       
following conditions we obtained a      
slightly different result1  which1      
nevertheless1 confirmed the preceding   
one4    ,on ,july #eth1 #ahgb1 we opened
 and closed twelve flasks similar to    
those  we had used before1 the sole     
difference being that they contained    
yeast  water#dg sweetened with ten per  
cent4 of sugar4 ,one of these flasks    
furnished us similarly with one kind of 
torula1 which bore the  greatest        
resemblance to the ferment of beer4     
,when this torula was  beginning to     
spread all over the bottom of our flask1

 we shook up the  liquid1 and turned the
 flask upside down1 with the object of  
submerging  the torula and depriving it 
of air1 at least at the bottom of the   
neck4  ,for some days1 and even months1 
there were no signs of the liberation of
  gas4 ,on ,july #bbnd1 #ahgc1 after the
 interval of a year1 we opened the      
flask 7which gave no indication of the  
existence of an interior  pressure7 and 
endeavoured to discover the presence of 
alcohol1 by means  of successive        
distillations1 as just described4 ,in   
the two first  distillates there seemed 
to be no alcohol1 but in the third we   
detected  its presence in very small    
quantity4 ,we shall see1 later on1 that 
the  formation of such a small quantity 
of alcohol may be attributed to the     
fact of the plant having been submerged 
when in full growth1 and to its  having 
continued to live for some time after   
its submersion quite  independently of  
the oxygen contained in the air of the  
flask4    ,from the previous facts it is

 obvious that there exist certain       
productions of various aspects1 the     
germs of which are particularly         
abundant in the dust of a laboratory    
where the phenomena of fermentation  are
 studied1 productions essentially       
aerial1 and incapable of giving  rise to
 fermentation1 although it may be       
impossible for the microscope  to       
distinguish their forms from those of   
true alcoholic ferments4    ,the idea of
 some physiological bond between these  
plants and the  ferments which resemble 
them in so remarkable a manner1 is one  
that  impresses itself forcibly and1 so 
to say1 instinctively upon the mind4    
,this remark holds good also in the case
 of mycoderma vini1 properly so  called1
 when compared with alcoholic ferments4 
,there appears to be no  other          
difference between the mycoderma vini   
and the torul of which  we are speaking1
 than that afforded by peculiarities of 
physical  structure and a certain       
greasiness in the cells of the former   

which  permits it to exist1 in the form 
of a scum1 upon the surface of liquids1 
that is to say unsubmerged4#dh    ,we   
have frequently1 but without success1   
endeavoured to bring about the          
conversion of these unsubmerged torul   
and mycoderma vini into  alcoholic      
ferments2 in other words1 we have never 
succeeded in imparting  to these torul  
or to mycoderma vini1 which bear so     
striking a  resemblance to alcoholic    
ferments1 the permanent fermentative    
character  peculiar to the latter4 ,at  
one period of our researches1 in #ahfb1 
and  more recently1 in #ahgb1 we thought
 that we had discovered the conditions  
under which such conversion might be    
possible1 but1 as we shall explain  in a
 subsequent chapter1 our experiments    
were affected by certain errors  that   
had escaped our notice4                 
,,vi4--,yeast may become ,dry and be    
,reduced to ,dust without losing its    
,faculty of ,reproduction4      ,in the 
preceding paragraphs we have given      

examples of liquids becoming            
impregnated with self-sown alcoholic    
ferments4 ,we shall proceed to show     
that this little cellular plant may     
actually exist in the form of dust1     
floating in the air1 after the manner of
 spores of fungoid growth and  the      
encysted forms of certain infusoria1    
without losing its powers of            
reproduction4    ,on ,december #afth1   
#ahgb1 we collected and pressed all the 
yeast resulting  from a brewing of about
 one hectolitre 7about #bb gallons74    
,from the  centre of the cake we took a 
few grammes 7#ej or #fj grains7 of      
yeast1  which we mixed in a porcelain   
mortar with five times its weight of    
plaster--both mortar and plaster having 
been heated1 just before1 in an  oil    
bath1 to a temperature of about #bjj ,c4
 7#cib ,f471 and then cooled  rapidly4  
,the powder thus prepared was           
immediately done up in a twist of       
paper1 which had been passed through the
 flame of a spirit lamp1 and the  twist 

and its contents were then placed in an 
oven at a temperature of  from #bj ,c4  
to #be ,c4 7about #ge ,f474 ,the object 
of these several  precautions was to    
free the powder composed of the yeast   
and plaster1 if  not from the germs     
contained in floating particles of dust1
 at all  events from those contained in 
the dust existing on the surface of the 
articles we used--the mortar1 plaster1  
and paper4    ,illustration3 ,fig4 #ad4 
,on ,december #ahth1 we took up with a  
platinum spatula1 previously passed     
through the flame1 a pinch of the       
yeast-and-plaster powder1 and sowed it  
in a two-necked flask 7,fig4 #ad7       
containing some pure wort4 ,we then     
placed the flask in an oven1 at #bj ,c4 
,on ,december #bast1 three days after we
 had sown the powder1 fermentation      
began to manifest itself by the         
appearance of patches of froth on the   
surface of the wort4 ,on ,december #aith
 and #bjth the yeast was sensibly       
developing1 although there was no       

liberation of gas to denote the         
presence of actual fermentation4 ,the   
yeast1 examined under the  microscope1  
appeared very pure4    ,on ,march #eth1 
#ahgc1 we took another pinch of the     
yeast-and-plaster  powder from the twist
 of paper1 and placed it in a flask of  
pure wort1  as in the foregoing         
experiment4    ,on ,march #ith1 that is1
 after having been subjected to a heat  
of #bj ,c4  7#fh ,f47 in the oven for   
four days1 fermentation began to        
manifest  itself by the appearance of   
patches of froth on the surface of the  
wort4  ,from this it was evident that   
the yeast had not been destroyed1 but   
only  retarded in its revival4    ,on   
,july #beth1 #ahgc--that is1 after a    
lapse of seven months and a half--we    
resumed our experiments1 and sowed some 
more of the yeast-and-plaster  powder in
 another flask of wort4 ,on ,august     
#bnd1 eight days from the time  of our  
sowing1 the little islets of froth      
appeared on the surface of the  liquid4 

,observed under the microscope1 the     
yeast still seemed pure1 and  resembled 
the original yeast2 we append a sketch1 
which will give an  idea of its shape   
7,fig4 #ae74    ,illustration3 ,fig4    
#ae4    ,on ,november #gth1 #ahgc1 we   
once more sowed some of the powder4     
,this time  the yeast was dead2 we      
observed the flask which contained it1  
day by  day1 until ,february #ast1      
#ahgd1 without detecting the slightest  
sign of  fermentation or development of 
the yeast that we had sown4 ,on         
,february  #ast1 we made a microscopical
 examination of the yeast1 and found it 
mixed with the plaster and absolutely   
inert at the bottom of the  saccharine  
liquid2 its cells were isolated1 very   
old-looking and  granulated1 without any
 appearance that might denote the       
possibility of  their ever budding      
again4    ,thus we determined that      
alcoholic ferment may be dried at the   
ordinary  temperature of the atmosphere1
 and preserved1 in the form of dust1 for

 a  period of seven months or longer1   
without losing its faculty of           
reproduction4 ,this faculty evidently   
diminishes in the course of time1  for  
our dried yeast1 after having been kept 
for seven months and a  half--all the   
other conditions of the two experiments 
having been  precisely the              
same--required about eight days to      
develop sufficiently to  reveal         
fermentation1 whilst1 immediately after 
the drying1 it only  required three or  
four days to accomplish the same thing4 
,illustration3 ,fig4 #af4    ,side by   
side with these experiments on alcoholic
 ferment1 we carried on  exactly similar
 ones with yeast obtained from 8high    
fermentation0  breweries4 ,on ,december 
#afth1 #ahgb1 we prepared a powder of   
this yeast  and plaster as before4 ,our 
last sowing took place on ,july #beth1  
#ahgc1 in  a flask of pure wort1 which  
showed signs of fermentation on ,july   
#bgth4  ,we append a sketch 7,fig4 #af7 
which gives the general aspect of this  

8high ferment10 when revived after such 
a lapse of time2 it had  preserved the  
distinctive features of the cells of    
8high ferment40    ,these facts can     
leave no doubt whatever as to the       
possibility of cells  of yeast existing1
 in a state of suspension in the air1 in
 the form of  fine dust1 particularly in
 a laboratory where researches on       
alcoholic  fermentation are pursued4    
,footnote #ba3      ,we have heard of   
liquids even less sensitive than these1 
which    required a temperature of #abj 
,c4 7#bdh ,f47 or more1 but we have had 
no opportunity of studying them4        
,footnote #bb3      ,see ,pasteur1      
,mmoire sur les ,gnrations dites        
,spontanes 7,annales    de ,chimie et de
 ,physique1 t4 lxiv4 #c;e srie1 anne    
#ahfb74    ,footnote #bc3      ,see my  
,mmoire sur les ,gnrations dites        
,spontanes1 already cited4    ,footnote 
#bd3      ,jules ,duval 7of             
,versailles71 ,nouveaux faits concernant
 la mutabilit    des germes             

microscopiques4 ,rle passif des tres    
classs sous le nom    de ferments4 7,see
 the ,journal d',anatomie et de         
,physiologie1 edited    by ,c4 ,robin1  
,sept4 and ,oct4 #ahgd1 and             
,compte-rendus de l',acadmie des        
,sciences1 ,nov4 #ahgd74 ,m4 ,bchamps   
had previously fallen into similar      
errors4    ,footnote #be3      ,on this 
subject see the observations of ,m4     
,coste 7,compte-rendus de    l',acadmie1
 t4 lix4 pp4 #adi and #ceh1 #ahfd74     
,footnote #bf3      ,chauveau's         
experiments were directed to show that  
the operation    bistournage1 employed  
by veterinary surgeons for castrating   
animals    by twisting and subcutaneous 
rupture of the spermatic cord1 an       
operation which1 though leading to the  
mortification and subsequent            
absorption of the testicles1 is commonly
 attended with no other    mischief to  
the animal1 does1 nevertheless1 lead to 
septic effects of    a serious          
character1 provided that septic         

germs--decomposing serum    containing  
vibrios1 for example--be introduced into
 the blood    current4 ,from the fact   
that the operation is ordinarily        
harmless1 ,m4    ,chauveau concludes    
that septic organisms are not produced  
by the    action of the constituent     
gases of the atmosphere--always present 
in    the blood--upon albuminous matter 
when outside vital influences2          
whilst1 from the success of the direct  
experiment of introducing    septic     
germs1 he concludes that the phenomena  
always arise from the    actual presence
 of such germs4--,d4 ,c4 ,r4            
,footnote #bg3      ,see ,pasteur1      
,mmoire sur les ,gnrations dites        
,spontanes1 pp4 #ea    and #eb1 #ahfb4  
,footnote #bh3      ,,davainne1         
,compte-rendus de l',acadmie des        
,sciences1 t4 lvii4 p4 #bbj1    #ahfc4  
,,coze and ,,feltz1 ,recherches         
cliniques et exprimentales sur les      
maladies infectieuses1 ,paris1 ,j4 ,b4  
,baillire1 #ahgb4 ,summary of all       

their works published before #ahfe4     
,dr4 ,,lister1 ,medical and surgical    
journals1 particularly the ,lancet1     
#ahfe-fg4      ,dr4 ,,gu,,rin1          
,compte-rendus de l',acadmie des        
,sciences1 ,march #bc1    #ahgd1 and    
,may #bh1 #ahgd1 also the ,report of ,m4
 ,gosselin1 ,december1    #ahed4        
,dr4 ,s,,dillot1 ,compte-rendus de      
l',acadmie des ,sciences1 ,november1    
#ahgd1 t4 lxxix4 p4 #aajh4              
,,pasteur1 ,mmoire sur la fermentation  
appele lactique4 7,annales de    ,chimie
 et de ,physique1 t4 lii4 #c;e srie1    
#ahge47--;,animalcules    infusoires1   
vivant sans gaz oxygne libre et         
dterminant des    fermentations4        
7,compte-rendus de l',acadmie des       
,sciences1 t4 lii4                      
#ahfa47--,recherches sur la putrfaction4
 7,compte-rendus de l',acadmie    des   
,sciences1 t4 lvi4 #ahfc47              
,,gosselin1 ,,robin1 and ,,pasteur1     
,compte-rendus de l',acadmie des        
,sciences1 ,january #e1 #ahgd4 ,urines  

ammoniacales4      ,,traube1 ,gazette   
hebdomadaire de mdecine et de chirurgie4
 ,sur la    fermentation alcaline de    
l'urine1 ,april #h1 #ahfd4              
,,chauveau1 ,putrfaction dans l'animal  
vivant4 7,compte-rendus de    l',acadmie
 des ,sciences1 ,april #bhth1 #ahgc47   
,footnote #bi3      ,we must mention one
 curious result1 which relates to what  
have been    called the crystals of the 
blood4 ,we could hardly have recourse to
 a    better method of preparing these  
crystals1 at least in the case of       
dog's blood1 which seems to yield them  
with the greatest facility in    any    
quantity we might desire to procure4    
,under the circumstances just           
recounted1 in which dog's blood exposed 
to contact with pure air    underwent no
 putrefactive change whatever1 the      
crystals of that blood    formed with a 
remarkable rapidity4 ,from the first day
 that it was    placed in the oven and  
exposed to an ordinary temperature1 the 
serum    began gradually to assume a    

dark brown hue4 ,in proportion as this  
effect was produced1 the globules of    
blood disappeared1 and the serum    and 
the coagulum became filled with very    
distinct crystals1 of a brown    or red 
colour4 ,in the course of a few weeks1  
not a single globule of    blood        
remained1 either in the serum or        
coagulum2 every drop of serum           
contained thousands of these crystals1  
and the smallest particle of            
coagulum1 when bruised under a piece of 
glass1 presented to view    colourless  
and very elastic fibrine1 associated    
with masses of    crystals1 without the 
slightest trace of blood-globules4      
,where our    observations were         
protracted1 it sometimes happened that  
all the    fibrine collected into one   
hyaline mass1 which gradually expelled  
every crystal from its interior4        
,footnote #cj3      ,,pasteur1 ,comptes 
rendus de l',acadmie des ,sciences1 t4  
lvi4 p4 #gch1    #ahfc4    ,footnote    
#ca3      ,,gayon1 ,comptes rendus de   

l',acadmie des ,sciences1 and ,annales  
,scientifiques de l'cole ,normale       
,suprieure1 #ahgd-ge4    ,footnote #cb3 
,amongst these influences one of the    
most important1 according to ,m4        
,fremy1 is 8organic impulse10--another  
gratuitous assumption4    ,footnote #cc3
      ,,fremy1 ,comptes rendus de       
l',acadmie des ,sciences1 t4 lviii4 p4  
#aafg1    #ahfd4    ,footnote #cd3      
,,fremy1 ,comptes rendus de l',acadmie  
des ,sciences1 t4 lxxiii4 p4    #adbe1  
#ahga4 ,m4 ,trcul shares ,m4 ,fremy's   
opinions1 and extends them to    the    
development of different fungoid        
growths4    ,footnote #ce3      ,this   
observation had already been made by    
,anthon and ,h4 ,hoffmann4 8,if    we   
scrape the surface of a gooseberry with 
a blunt knife10 says ,h4    ,hoffmann1  
8and put under the microscope the       
scrapings1 which are of a    whitish    
colour1 we shall recognize amongst many 
varieties of shapeless    dirt1 earthy  
particles and other things1 the same    

fungoid spores that    we find in the   
expressed juice1 but we shall see them  
there in    infinitely larger           
quantities4 ,some of them will be of a  
dusky colour    7,stemphylium1          
,cladosporium71 and others will be      
colourless2 the    shape of these latter
 will be round or oval1 and cylindrical4
 ,most of    them will bear resemblance 
to beads of the chaplets of ,oidium1    
,monilia1 ,torula 7that is to say1 to   
spores of certain    ,hyphomycetes71    
which have been detached and carried off
 by the wind1    and have attached      
themselves to the fruit4 ,some of these 
spores will    be already provided with 
short germinating filaments40 7,annales 
des    ,sciences ,naturelles1           
,botanique1 t4 xiii4 p4 #ba1 #ahfj74    
,footnote #cf3      ,the experiments    
that we have described give rise to a   
useful remark4    ,all the organic      
liquids1 boiled or not1 in the course of
 time must    take up oxygen from the   
air4 ,at the same time1 and certainly   

under    this influence1 they assume an 
amber or brownish colour1 but this      
effect is only produced when the liquids
 are placed under conditions    of      
unalterability4 ,should fermentation or 
the development of fungoid    growths be
 possible1 scarcely any change of colour
 will take place4    ,doubtless this    
non-coloration may be attributed to the 
fact that these    organisms consume the
 oxygen necessary for coloration4 ,in   
these    experiments on must1 all the   
unchanged flasks assumed a pale         
yellowish    brown colour2 those which  
fermented or contained fungoid growths  
remained colourless1 or nearly so4      
,footnote #cg3      ,comptes rendus de  
l',acadmie1 sance du #bh ,octobre1      
#ahgb4    ,footnote #ch3                
,,gay-,,lussac1 ,annales de ,chimie1 t4 
lxxvi4 p4 #bde2 read at the             
,institute1 ,december #crd1 #ahaj4 ,long
 before ,gay-,lussac1 it had been       
remarked that atmospheric air had a     
great influence on fermentation4    ,see

 ,m4 ,chevreul's articles on the history
 of chemistry in the ,journal    des    
,savants4    ,footnote #ci3             
,,gay-,,lussac1 ,annales de ,chimie1 t4 
lxxvi4 p4 #bdg1 ,mmoire cit1    #ahaj4  
,footnote #dj3      ,it is well to      
notice that under the influence of      
fungoid growths1    properly so called1 
the wort of beer speedily becomes       
bright4 ,we may    say that fungoid     
growths1 by their rapid development1    
clarify the    must1 which serves to    
nourish them4    ,footnote #da3      ,it
 has already been observed in our       
,memoir on spontaneous generation1      
that alcoholic fermentation is not      
always to be obtained by sowing    wads 
of cotton or asbestos1 charged with the 
particles of dust which    float through
 the air1 in saccharine musts that are  
in contact with    much air4 ,the air   
which furnished the particles of dust1  
in the    experiments to which we are   
alluding1 was taken outside the         
laboratory1 in a neighbouring street4   

,footnote #db3      ,the decanting into 
the flasks is necessary1 because of the 
possibility    of the fermentation in   
the basins being masked4 ,see further on
 the    note on p4 #ge4    ,footnote    
#dc3      ,this small ferment is very   
curious1 although it scarcely affects   
industrial fermentation4 ,it was first  
described in #ahfb4 7,,pasteur1         
,bulletin de la ,socit chimique1 #ahfb1 
page #fg1 and following3    ,quelques   
faits nouveaux au sujet des levres      
alcooliques47 ,it has    since been     
described by ,dr4 ,rees under the name  
,saccharomyces    apiculatus4 7,dr4     
,rees1 ,leipzig1 #ahgj3 ,sur les        
champignons de    fermentation          
alcooliques4 ,see also ,dr4 ,engel1     
,thse pour le    ,doctorat1 ,paris1     
#ahgb47 ,if we carefully filter some    
grape must at the    time of vintage1 we
 may be sure that we shall see it appear
 in the    clear liquid at the bottom of
 our vessel1 without intermixture with  
any other ferment4      ,should we not  

filter the must this ferment will appear
 all the same1    but it will soon      
become associated with another1 thicker 
in appearance    and more elongated1    
which also is one of the ferments       
peculiar to the    fermentation of grape
 must4    ,footnote #dd3      ,we may   
remind the reader that in #ahfb1 in our 
,mmoire sur les    ,gnrations dites     
spontanes1 we applied the expression of 
torula    to all the little cellular    
plants of spontaneous growth1 excepting 
mycelium1 propagated by budding1 after  
the manner of the ferment of    beer4   
,at the same time1 stress was laid upon 
the frequent occurrence    of their     
germs1 especially in our laboratory1    
where studies on    fermentation were1  
even then1 carried on4 ,plate ,,iii4    
represents two of    these ferments4    
,footnote #de3      ,it is to be        
remarked that in this case1 as in the   
case recorded  ,,iv4    p4 #gj1 in order
 to detect with certainty any alcoholic 
ferment1 the    contents of the basins  

were transferred to a long-necked flask2
 since    where1 as in the basins1 a    
liquid has a large surface exposed to   
spontaneous impregnation1 the strictly  
alcoholic fermentation may    escape    
observation4 ,the reason of this is     
that1 when a liquid of large    surface 
but small depth is exposed to the air it
 affords a suitable    medium for the   
active development of moulds1 which1 by 
absorbing the    oxygen which would     
dissolve in the liquid1 checks the      
growth of the    ferment1 or even       
prevents its germination altogether4 ,as
 a matter of    fact we shall see that  
for their growth and multiplication     
ferment    cells1 and still more ferment
 germs 7the difference between the      
two will appear in ,chap4 ,v471 require 
a larger supply of oxygen just    in    
proportion to their age1 state of       
desiccation1 and distance from    the   
budding condition4 ,now1 if the spores  
of moulds be present and    effect a    
settlement in the liquid1 the increase  

of the ferment1 or    even its actual   
germination1 is prevented4 ,but by      
collecting the    liquid in a deep and  
narrow vessel1 such as a long-necked    
flask1 after    it has been exposed to  
spontaneous impregnation1 we deprive the
 moulds    almost completely of oxygen1 
and so allow the ferment to exert its   
peculiar energies4 ,the mere act of     
transferring enables the liquid to      
take up a sufficiency of oxygen1 and a  
liberation of gas very speedily    shows
 that fermentative action is going on4  
,we must add further that    sometimes  
in a liquid of large surface and shallow
 depth1 in which but    little ferment  
is formed1 the evolution of carbonic    
acid gas may fail    to be detected1 by 
reason of its diffusing itself into the 
air slowly    as it is formed4          
,footnote #df3      ,here we had to seek
 for a most minute quantity of alcohol1 
that no    alcoholometer could have     
indicated4 ,a certain sign of the       
presence of    alcohol is contained in  

the first few drops distilled2 these    
always    assume the form of little     
drops or stri or1 better still1 oily    
tears1 when alcohol is present in the   
distillate4 ,the distillation    should 
be effected with a small long-necked    
retort and a ,liebig's    condenser4 ,we
 must carefully watch the neck of the   
retort at the    moment of boiling2     
should the liquid contain #a_/ajjj part 
of its volume    of alcohol1 we shall   
observe the indications given above for 
a short1    but appreciable time4       
#a_/aj1jjj of alcohol is difficult to   
judge1 but    with care and practice we 
may do it without failing4 ,collecting a
    third of each distillate1 and       
supposing the limit of appreciation to  
stop at thousandths1 in three           
distillations we may easily detect the  
presence of #a_/aj1jjj of #a c4c4 of    
alcohol in a total volume of #ajj       
c4c4    ,footnote #dg3      ,yeast when 
macerated in water imparts to it certain
 soluble    nitrogenous materials4 ,the 

solution so obtained1 filtered from     
yeast    globules1 is known as yeast    
water4--,d4 ,c4 ,r4    ,footnote #dh3   
,it is possible that this greasiness in 
the cells of the common    mycoderma    
vini arises simply from the composition 
of the liquid in    which it vegetates4 
,it is in saccharine liquids that the   
submerged    torul are found2 fermented 
liquids more readily give birth to the  
forms of torul and mycoderma vini which 
exist as a scum4 ,in all    probability1
 however1 there is no radical difference
 between these two    kinds of little   
cellular plants of aerial growth1 the   
floating    torul and mycoderma vini4   
,,chapter ,,iv4       ,the ,growth of   
,different ,organisms in a ,state of    
,purity3 ,their                         
,autonomy4#di      ,our observations in 
the preceding chapter will have shown   
that organic  liquids1 natural or       
artificial--the wort of beer amongst    
others--if  exposed to contact with the 
air1 rapidly develop various forms of   

life4  ,this is a natural consequence of
 the mode of impregnation4 ,the         
fertility  of the liquid depends on the 
various microscopic germs which are     
deposited in it by the common air1 and  
these1 again1 as regards their  nature  
and number1 are dependent upon the      
situation of the vessel  containing     
them1 its height above the ground1 the  
time of year1 the  disturbance of the   
atmosphere1 and other causes4    ,the   
fortuitous association of other forms1  
in growths which we believe  to be      
uniform and independent1 constitutes one
 of the principal  difficulties that    
occur in the study of the lower         
organisms1  particularly that of fungoid
 growths4 ,the fact that the germs of   
many of  these little beings exist in   
the atmosphere in the form of dust1     
invisible to the naked eye1 or1 as such1
 spread over the surface of the         
different materials and objects used in 
experiments1 exposes the student  to    
constant risk of wrongly interpreting   

the results which come under  his       
notice4 ,he has sown a plant1 and is    
observing the course of its             
development4 ,without his knowledge1    
spores of another plant have got  mixed 
with his growth1 and germinated4 ,in his
 ignorance1 he will  attribute all that 
he sees1 all the changes which he       
describes and which  he sketches1 and   
all the conclusions which he draws1 to  
the one plant  which engages his        
attention4 ,if he is dealing with       
bacteria1  vibrios1 and1 generally      
speaking1 the infinite variety of mobile
  microscopic organisms1 his            
embarrassment will be greater still4    
,again1  inasmuch as the medium which   
serves as substratum for growths has a  
considerable influence on the fertility 
of the germs in contact with it1  as    
well as on their ulterior development1  
it often happens that germs  deposited  
fortuitously by the particles of dust   
which fall from the  atmosphere or      
collect on objects are fertile and      

multiply with rapidity1  whilst those   
which have been directly sown1 no matter
 in what number1  remain sterile1 or    
multiply very slowly4 ,if we place in a 
young wine  some mycoderma aceti1 we    
shall obtain mycoderma vini2 by placing 
some mycoderma vini in an old wine1     
especially if it is a little acid1  we  
shall obtain mycoderma aceti4#ej ,it is 
from facts of this kind1  wrongly       
interpreted1 that many errors have crept
 into our knowledge of  the lower       
organisms1 and that we are constantly   
seeing old discussions  crop up1 both on
 the subject of so-called spontaneous   
generation and  on that of the theory of
 fermentation4 ,at every step in the    
course of  this work we shall see the   
trace of these complications1 as well as
 the  influence they have had on the    
progress of our knowledge4    ,in       
opposition to these results1 we will    
study the case of wort sown  directly   
with germs distinctly of one kind1      
unmixed with any other4                 

,i4--,growth of ,penicillium ,glaucum   
and ,aspergillus ,glaucus in a ,state of
  ,purity--,proofs that these ,fungoid  
,growths do not become ,transformed into
    the ,alcoholic ,ferments of ,beer or
 ,wine4--,preliminary ,enquiry into the 
,cause of ,fermentation4      ,let us   
again take one of the flasks furnished  
with two necks such as we  have already 
described1 and let it be supposed that  
this flask contains  a quantity of      
saccharine wort1 brewed some            
considerable time ago1 which  has       
undergone no change whatever1 except in 
colour1 the slow process of  oxidation  
having gradually darkened the original  
colour of the liquid4  ,what we have to 
do is to drop into this unchanged and   
fertile liquid  some grains or spores of
 penicillium which are free from the    
slightest  trace of the spores or germs 
of other microscopic organisms4    ,one 
means of effecting this consists in     
taking up with a pair of  metallic      
forceps1 previously heated1 a piece of  

platinum wire1 one or  two centimetres  
7about #c_/d in47 in length1 which we   
also pass through  the flame of a spirit
 lamp1 and with which1 as soon as it is 
cold1 we  touch a mass of sporanges of a
 growth of penicillium4 ,no matter how  
few spores may be taken up on the end of
 the platinum wire1 we shall  have far  
more than we require for the            
impregnation of the liquid4 ,at the     
moment of charging the point of the wire
 we withdraw the glass stopper  which   
closes the india-rubber tube on the     
right-hand neck of the flask  7,fig4    
#ad7 and drop the wire through that     
tube2 we then replace the glass         
stopper1 after having1 by way of        
additional precaution1 passed it        
rapidly through the flame of the lamp4  
,there is no doubt that we expose       
ourselves to error in consequence of    
having to convey the wire through  the  
surrounding air1 and also1 in           
consequence of having previously to     
open the flask2 but1 as we have already 

remarked1 this double cause of  error   
has never1 we may say1 interfered with  
the exactness of our  experiments1 the  
volume of air with which we are         
concerned being  exceedingly limited4   
,moreover1 our flask being in free      
communication  with the exterior air1 by
 means of the opening in the curved1    
slender  tube1 there is no inrush of air
 when we withdraw the stopper4 ,the     
chance  of encountering a spore or      
fecund germ and introducing it into the 
flask  on the wire that is charged with 
the others1 is so remote that we have   
considered it unnecessary to adopt a    
more perfect apparatus1 which might     
easily have been devised had we felt    
that it was necessary4    ,a more       
serious cause of error may occur in the 
preceding method2  resulting from the   
possible impurity of the spores taken   
from a field of  penicillium which has  
developed in contact with common air4   
,this field  receives1 every instant1   
and has received throughout its growth1 

particles of dust which have fallen from
 the atmosphere2 thus1 it may  not be1  
and1 as a matter of fact1 is not1 free  
from the germs of other  fungoid        
growths4#ea    ,the operator1 without   
knowing it1 may frequently sow1 besides 
the  penicillium1 which is all he can   
see1 spores of mucor mucedo and         
mycoderma vini1 in short1 of all the    
most common fungoid growths4            
,illustration3 ,fig4 #ag4    ,this      
process of impregnation1 therefore1 does
 not afford us sufficient  safeguards1  
but by means of the following device we 
shall render it more  satisfactory4 ,let
 us take a series of flasks shaped as in
 ,fig4 #ag1  containing an organic      
liquid suitable to the development of   
fungoid  growths1 that is to say1       
slightly acid--yeast-water1 plain or    
sugared1  the wort of beer1 or ,raulin's
 fluid#eb will answer our purpose2 let  
us  boil the liquid1 and having         
previously drawn out the necks1 let us  
close  the ends in the flame of a lamp  

whilst the steam is escaping1 as soon as
  we judge that the air has been nearly 
all expelled4 ,having prepared ten  or  
twenty of these flasks in this manner1  
when they are cold we may  break their  
points in any place we may be in4 ,the  
air will rush into the  flasks1 and we  
must then seal them up again in the     
flame of the lamp1  and put them aside  
for future observations4 ,in a certain  
number of these  flasks1 as we have     
already explained in our experiments    
carried on after  this fashion1 we shall
 see some fungoid growths appear1 first 
in the  shape of flakes of mycelium     
floating in the liquid1 and afterwards  
coming to the surface to fructify4 ,now1
 it often happens that  penicillium     
glaucum appears alone1 so numerous are  
the spores of this  fungus floating in  
the air4 ,under such conditions1 we     
shall evidently  obtain a field of      
sporanges quite free from the presence  
of other  organisms4 ,if we now take off
 the neck of one of the flasks          

containing  the pure penicillium1 and   
take out some of the germs with our     
platinum  wire1#ec we shall thus obtain 
with most certainty spores of           
penicillium free from impurities4       
,our readers will excuse the length of  
these details and the minuti of  our    
precautions1 but we shall again and     
again see that to neglect them1  or any 
part of them1 is to expose ourselves to 
hazard in drawing sure  conclusions from
 facts which come under our observation4
    ,illustration3 ,fig4 #ah4    ,on    
,june #agth1 #ahgb1 we placed some pure 
spores of penicillium in a  series of   
three flasks containing wort 7,fig4     
#ah71 observing all the  precautions    
that we have indicated4 ,we shall       
designate these flasks by  the letters  
,a1 ,b1 ,c4 ,on the following day the   
spores germinated1 and the  liquid      
became full of flakes of mycelium1 some 
of which came to the  surface to        
fructify4 ,the temperature varied       
between #be ,c4 and #cj ,c4  7#gg to #hf

 ,f474    ,on ,june #bbnd1 small        
patches1 with whitish borders and green 
centres1  developed on the liquids4 ,we 
then shook up the flask ,a1 in order to 
submerge the plant and the spores4#ed   
,we also shook the flask ,b1 after      
observing the precaution of sealing up  
the slender bent tube4#ee ,the  flask ,c
 was attached on one side to an         
aspirator1 on the other to a tube       
filled with cotton1 and every day we    
renewed the air in it4    ,during the   
weeks and months over which our         
observations extended1 there  was not   
the least formation of yeast in these   
flasks2 moreover1 we have  frequently   
repeated this and other experiments of a
 similar kind1  without ever detecting  
the appearance of either ordinary yeast 
or any  other true alcoholic ferment4   
,the experiments may be made with       
saccharine juices that are highly       
favourable to the development of        
bacteria and lactic ferment4 ,these     
latter appear equally incapable of      

transformation into yeast1 which has    
never been seen to develop in           
experiments where they were used1 if    
proper precautions have been taken  to  
secure a pure growth4 ,should we neglect
 any of the precautions that  are       
necessary to secure the purity of our   
spores1 we may of course  obtain        
different results4 ,if1 for instance1 we
 sow spores of  penicillium grown in    
free contact with the atmosphere1 and   
consequently exposed to the particles of
 dust floating therein1 we shall        
frequently observe1 mixed with the      
fruiting hyph of the fungoid growth1    
yeast and mycoderma vini and torul1 or  
even bacteria and lactic  ferment4 ,thus
 we shall be led to believe1 in all good
 faith1 that we  have under our eyes    
examples of the changes of spores of    
fungoid growth  into cells of ferment1  
or proofs of the conversion of bacteria 
or  lactic ferment into the same cells4 
,causes of error of this nature have    
induced some ,german naturalists to     

believe that they have succeeded in     
proving1 beyond the possibility of      
doubt1 that a number of fungoid growths 
may produce alcoholic ferment1  and that
 they have clearly demonstrated that    
spores of these fungi may  become       
transformed into yeast4 ,in #ahef ,m4   
,bail1 and1 about the same  time1       
,berkeley1 and1 later on1 ,h4 ,hoffmann 
and ,hallier1 have  successively        
entertained these views1 which were     
introduced into science  by ,m4 ,turpin4
 ,we have combated them since the year  
#ahfa4ef ,since that  period they have  
lost rather than gained ground abroad1  
in spite of the  growing favour bestowed
 on the ,darwinian system4 ,one of the  
mycologists  who enjoy the most         
legitimate authority beyond the ,rhine1 
,m4 de ,bary1  has arrived1 as we have1 
at absolutely negative results4    ,a   
simple perusal of what has been written 
in favour of the  transformations which 
we are discussing causes us to entertain
 the  gravest doubts as to the          

correctness of results which are quoted 
as  decisive4 ,we need only give one    
example1 which we extract from a paper  
by ,m4 ,h4 ,hoffmann4    8,in some      
cases10 this author writes1 8and under  
favourable  circumstances1 ,i have been 
able to see the ferment produce         
filaments1  both small specimens that   
could be examined immediately under the 
microscope1 and also large specimens1   
and ,i have recognized1 amongst  other  
varieties1 penicillium glaucum1         
ascophora mucedo1 ascophora  elegans1   
and periconia hyalina1 sometimes        
isolated1 sometimes  intermixed4 ,this  
result is most easily to be obtained by 
the following  method3--,pour a small   
quantity of water into a test-tube1     
which should  then be placed slantingly3
 introduce some fresh yeast into the    
middle  part of the tube1 and close the 
tube with a wad of cotton1 to prevent   
the entrance of exterior particles of   
dust4 ,in this vapour-filled  receptacle
 we shall sometimes see flakes develop4 

,it seems that ,messrs4  ,berkeley and  
,g4 ,h4 ,hoffmann have also obtained    
penicillium from  ferment1 by a similar 
process40#eg    ,why1 however1 should it
 not be admitted that penicillium found 
under  such conditions may be derived   
from spores of that growth1 adhering to 
the sides of the tube before it is      
closed with the wad1 or mixed with  the 
yeast that is put into the tube8    ,the
 facts alleged during the last few years
 by ,m4 ,bail1 who persists in  his     
views1 in spite of their apparently     
greater exactness1 are also far  from   
being satisfactory4#eh    ,m4 ,trcul1   
who is almost the only one in ,france1  
besides ,messrs4 ,ch4  ,robin and       
,fremy1 to participate in these errors1 
does not confine  himself to affirming  
the change of the spores of penicillium 
into  yeast1 and vice vers2 his system  
is a far more extensive one4            
8,according to my observations10 he     
says1 8there would be the following     
series of changes2 albuminous matter    

changed into bacteria1 or  directly into
 alcoholic ferment1 or into mycoderma2  
bacteria into  lactic ferment1 there    
becoming immoveable2 lactic ferment into
 alcoholic  ferment2 alcoholic ferment  
into mycoderma cerevisi2 finally1       
mycoderma cerevisi into penicillium4#ei0
    ,m4 ,trcul does not stop here4 ,he  
goes on to explain the principal of     
these changes1 as though his testimony  
were quite beyond refutation3    8,if we
 use a perfectly filtered wort1         
containing no granulations1 and         
prepared at a temperature between #fj   
,c4 and #gj ,c4 7#adj ,f4 and #afj      
,f471 there will first of all appear a  
multitude of fine granules that  will   
develop into active bacteria1 which1    
losing the faculty of motion1  will     
constitute lactic ferment1 as ,i have   
repeatedly pointed out4 ,a few  days    
after the appearance of the first       
granules1 we shall perceive  others     
rather larger in size and isolated4     
,these will increase in size1  and1 in  

the course of time1 assume the form of  
little globuloid1 or  elliptic cells2   
they will not commence to bud before    
they have attained  a comparatively     
large size1 approaching that of ordinary
 yeast1  consequently1 there will be a  
considerable interval of time1 during   
which the young cells will present no   
buds1 especially if we work at a  low   
temperature1 as from #bj ,c4 to #ce ,c4 
7#fh ,f4 to #ie ,f47    8,as for the    
transformation of the spores of         
penicillium into alcoholic  ferment1 the
 possibility of which ,m4 ,pasteur also 
denies1 ,i have very  often obtained it 
by using liquids1 such as boiled wort   
and sugared  barley water1 which had    
stood for a month or six weeks without  
setting  up an alcoholic fermentation4  
,these liquids1 sown with spores of     
different forms of penicillium1 chosen  
when young and in full growth1          
fermented after a varying number of     
days1 even at a temperature of #ab  ,c4 
7#ed ,f471 the condition of fermentation

 being that the flasks were  closed with
 very elastic corks1 which had been     
boiled for a quarter or  half an hour2  
these corks1 as ,i have already pointed 
out1 it is best to  keep for a month    
after the boiling1 to make sure1 by     
drying them  thoroughly again1 of       
destroying any mycelia adhering to them4
 ,it is  necessary to keep the flasks   
stoppered that the corks may be always  
moist1 and it is also advisable to shake
 the flasks once or twice a day1  to    
secure the submersion of the spores4 ,if
 these conditions are carried  out1 we  
shall soon see the spores increase in   
size1 gradually lose their  green colour
 and then bud1 and often a very active  
fermentation will  manifest itself4 ,all
 the spores will be transformed1 if the 
flasks are  perfectly air-tight40#fj    
,such is the manner in which ,m4 ,trcul 
regards these changes4 ,his is  entirely
 a system of spontaneous generation1    
worked out into minutest  detail1 from  
the transformation of the albuminous    

substances to the  formation of cells of
 the higher organisms1 passing from the 
disintegration of the original          
substances to the formation of very fine
  granules1 from these to the creation  
of active bacteria1 which last1  in     
their turn1 become lactic ferment       
through the simple cessation of  their  
faculty of moving and so on4 ,we regard 
all this as purely  imaginary4 ,as a    
matter of fact1 ,m4 ,trcul's argument is
 based on the  successive phenomena     
which manifest themselves in filtered   
wort  8containing no granulations40 ,as 
,m4 ,trcul reasons1 this condition is a 
necessity1 for he starts with the       
assertion that the albuminous           
substances in the wort become changed   
into granulations 8that will  develop   
into active bacteria40 ,this is another 
of ,m4 ,trcul's illusions4  ,no doubt we
 may filter hopped wort to almost       
perfect clearness1 but we  can only do  
this when it is cold4 ,if we filter it  
warm1 it will be  bright as long as it  

remains warm1 but as soon as cold it    
will appear  turbid1 in consequence of  
the great number of minute granules     
floating  in it4 ,again1 cold wort1     
however little it may be or has been in 
contact  with air1 undergoes a process  
of oxidation1 and this oxidation1 which 
acts principally on the colouring or    
resinous matter1 causes a deposit  of   
fine granules1 the number of which is   
constantly increasing as  oxidation goes
 on4 ,these granules form an absolutely 
inert precipitate  which1 under no      
possible circumstances1 can become      
transformed into  active bacteria4      
,nothing can be easier than to prove    
this fact1 by  taking some of our       
two-necked flasks 7,fig4 #d7 and        
preparing pure wort in  them1 by        
boiling1 and then leaving it to cool and
 undergo the process of  oxidation4 ,in 
wort thus exposed to the air--the air   
being pure and free  from germs--there  
will be formed a granular deposit1 which
 will never  become active or transform 

itself into any kind of organism        
whatever4    ,we may also remark that   
whilst ,m4 ,trcul used wort in his      
experiments1  he does not tell us if it 
was hopped or not4 ,had ,m4 ,trcul      
informed us  that the facts which he    
described applied to unhopped wort1 we  
should  reply that a temperature of #fj 
,c4 or #gj ,c4 7#adj ,f4 or #afj ,f47 is
  quite insufficient to kill the germs  
of bacteria existing in such a  wort4   
,hopped wort should be heated to #gj ,c4
 or #ge ,c4 7#afj ,f4 to #agj  ,f471    
that it may remain inert after having   
cooled down in contact with  pure air2  
unhopped wort must be heated to about   
#ij ,c4 7#aid ,f474    ,in short1       
whatever may be the case1 it must be    
evident to our readers  that the active 
bacteria observed by ,m4 ,trcul existed 
in the form of  germs in the wort that  
he used1 and that what he observed was  
nothing  more than the development of   
these germs when brought into contact   
with  the air held in solution in the   

liquid4    ,as for the success of ,m4   
,trcul's experiments on the penicillium1
 we  have no doubt that that gentleman  
has sown germs of yeast or torul1  which
 bear so striking a resemblance to      
yeast1 at the same time that he  sowed  
spores1 since he took his spores from   
sporangia of penicillium  that had been 
exposed to contact with ordinary air4   
,the conditions under  which ,m4 ,trcul 
conducted his experiment rendered it    
difficult for the  spores--although1    
relatively1 much more numerous than the 
contaminating  germs of ferment with    
which they happened to be associated--to
 make way  against these latter1 since  
the spores were unable to continue their
  development in a medium that was      
deprived of oxygen4 ,on the other hand1 
the cells of ferment might easily have  
multiplied to such an extent as  to make
 the discovery of the spores that had   
been sown a matter of some  difficulty1 
since those spores would have been lost 
amongst the great  number of cells of   

ferment4 ,this was1 probably1 one of the
 causes which  led to the mistaken      
notion that such spores underwent       
conversion into  cells of ferment4 ,now 
although botanists describe several     
varieties of  penicillium glaucum1 we do
 not suppose that the cause of the      
difference between our results and those
 obtained by ,m4 ,trcul can be          
attributed to our having operated upon a
 different variety of  penicillium from 
that which he used4 ,supposing that     
there had been a  great difference      
between our two varieties1 still ,m4    
,trcul declares  that he has realized   
the phenomenon with numerous varieties  
of this  fungus4    ,m4 ,trcul expresses
 himself as follows3 8,i have used      
spores of  penicillium of several       
varieties in these experiments3         
,firstly1 thick1  green1 elliptic spores
 of a variety of penicillium that grows 
on  lemons2 secondly1 elliptic spores of
 a bluish colour and smaller than  the  
preceding1 of another variety of        

penicillium found on lemons2  thirdly1  
spherical spores of the variety termed  
penicillium  crustaceum2 fourthly1      
spores of the penicillium that develops 
on the  yeast of beer4#fa0    ,this     
criticism of ,m4 ,trcul's opinions was  
written on the occasion of a  discussion
 at the ,academy1 after we had been     
induced to read over again  the remarks 
which he had published on the subject4  
,we were so impressed  by the positive  
manner in which his conclusions were    
stated1 that we  asked ourselves1 once  
more1 which of us could be mistaken1 and
 once  more1 also1 we applied ourselves 
to fresh experiments1 which we          
conducted with every possible           
precaution1 following1 as far as we     
could  without falling into the errors  
of which we accuse the learned botanist1
  the mode of procedure that he adopted4
 ,as his descriptions struck us as      
being at times insufficient1 we resolved
 to ask him for certain  explanations   
viv voce 7,november #crd1 #ahgc71 which 

he gave us with the  greatest           
willingness4    8,every variety of      
penicillium10 said ,m4 ,trcul1          
8especially when young  and vigorous1 is
 amenable to transformation into        
ferment4 ,this is the  way in which ,i  
operated2 ,i had some little flasks of  
#cj c4c4 to #dj c4c4  7about #a- fluid  
ounces7 in capacity1 filled quite full  
with wort1 or1  at least1 containing    
very little air1 closed perfectly       
air-tight with  corks which ,i had kept 
for a quarter of an hour in boiling     
water4 ,these  flasks when corked were  
heated to #fj ,c4 or #gj ,c4 7#adj to   
#aeh ,f474  ,after they had cooled ,i   
uncorked them1 and introduced into them 
the  spores which had been prepared as  
follows3 ,i placed on a piece of glass  
some spores of the variety of           
penicillium that ,i wished to study1    
taken with a pair of forceps from a     
mouldy lemon1 and ,i mixed these  spores
 with a drop of wort and observed them  
under the microscope to  assure myself  

that they contained nothing of a foreign
 nature2 then ,i  poured my drop of wort
 from the piece of glass into one of the
 flasks1  which ,i recorked and laid    
down4 ,the transformation into ferment  
took  place next day40    ,provided with
 these new data we set to work again and
 prepared a series  of little flasks    
which were filled quite full with hopped
 wort1 or  contained but very little    
air1 as ,m4 ,trcul had recommended4     
,these we  heated in a hot water bath to
 #gj ,c4 7#aeh ,f47 at least2 we then   
impregnated them1 observing the         
necessary precautions1 which we         
described at the commencement of this   
paragraph--not working in the  evidently
 defective manner in which ,m4 ,trcul   
had done4 ,taking his  spore-seeds from 
a field of sporanges exposed to the air1
 and afterwards  manipulating them1 in  
contact with the air1 in water on a     
piece of  glass1 before he made his     
microscopical examination1 his          
experiments  were conducted under       

circumstances in every way conducive to 
the  introduction of causes of error4   
,one of the most serious of those causes
  is that which results from the        
substratum of the spores as taken from a
  mouldy lemon4 ,if ,m4 ,trcul will     
examine under the microscope the water  
in which any lemon has been washed--even
 a sound lemon1 unattacked by any       
fungoid growth--he will immediately see 
the cause of error to which his  method 
of working exposes him4 ,germs of       
microscopic organisms exist  abundantly 
on the surface of all fruits4    ,having
 impregnated the liquids in our flasks  
with spores from a quantity  of pure    
sporangia grown in a closed vessel1     
gathered on the point of a  platinum    
wire1 which had first been heated and   
then allowed to cool1 we  found that in 
each case1 without exception1           
germination took place1 then  a mycelium
 was developed1 which soon1 however1    
ceased to grow from  want of a proper   
supply of air2 but not in any single    

case was there the  faintest trace of   
fermentation1 formation of yeast1 or    
appearance of  bacteria or lactic       
ferment4    ,we repeated these          
experiments1 using unhopped wort instead
 and obtained  similar negative results4
 ,we had previously determined that it  
was  necessary to heat flasks of hopped 
wort to #gj ,c4 7#aeh ,f471 at least1   
and those of unhopped wort to #ij ,c4   
7#aid ,f47 to secure them from  further 
change4    ,in short1 contrary to the   
assertions of ,m4 ,trcul1 ,m4 ,h4       
,hoffmann1 and  other naturalists1 it is
 not true that the spores of penicillium
 can  change into alcoholic ferment4    
,regarded from another point of view1   
growths of pure penicillium will  give  
us some remarkable results1 the         
interpretation of which seems to us  to 
be intimately connected with the        
physiological theory of fermentation    
that we shall discuss in a subsequent   
chapter4 ,it is a question as to  the   
production of alcohol whilst the life of

 the plant is carried on  under certain 
conditions of growth4    ,if we distil  
saccharine liquids on the surface or in 
the body of which  we have grown        
penicillium1 and repeat the distillation
 in the manner  that we have already    
described for the detection of the      
minutest  quantities of alcohol1 we     
shall readily find that those liquids   
frequently do contain a little ordinary 
alcohol4 ,moreover1 if we regard  the   
quantities of alcohol produced1 which   
are always very minute1 seldom          
exceeding #a or #ae thousandth of the   
total volume of the liquids1 we  shall  
find that there is no fixed proportion  
between this alcohol and  the weights of
 the plants formed4 ,it is possible1 for
 instance1 that we  may obtain more     
alcohol from one plant than from another
 weighing a  hundred times as much4     
,often1 however1 when the vegetation is 
abundant  we cannot make out the        
occurrence of alcohol in spite of the   
sensitiveness of the process described  

7p4 #gh74    ,what can be the cause of  
these varying results relating to the   
production or non-production of alcohol 
in the vegetation of the little  plant8 
,the numerous experiments that we have  
made seem to demonstrate  positively    
that they are dependent upon variations 
in the amount of air  or oxygen that is 
supplied to the fungoid growths1        
whether1 that is1 the  vegetating       
mycelium alone be submerged1 or the     
whole plant with its  organs of         
fructification4 ,when the plant has at  
its disposal an excess  of oxygen1 as   
much as its vitality can dispose of1    
there is no alcohol1  or very little1   
formed4 ,if1 on the other hand1 the     
plant vegetates with  difficulty1 in    
presence of an insufficiency of oxygen1 
the proportion of  alcohol increases2 in
 other words1 the plant shows a certain 
tendency to  behave after the manner of 
ferments4    ,some time ago1 wishing to 
assure ourselves that the spores of     
penicillium could not become transformed

 into ferment1 we sowed some  pure      
spores in small flasks1 holding from #ej
 c4c4 to #ajj c4c4 7from #b to  #d fl4  
oz471 which contained very little air1  
and which were sealed  hermetically     
after the sowing4 ,under these          
conditions1 the germination  and growth 
of the spores proceeded with great      
difficulty1 and soon  ceased through    
want of air4 ,the total weight of the   
little plant was too  small to be       
determined4 ,in cases of this kind1 if  
we distil the whole of  the liquid we   
shall often see the alcohol appear in   
the second  distillation1 even though   
the weight of the plant may have been   
scarcely  appreciable4 ,if1 on the other
 hand1 side by side with experiments of 
this kind1 we grow pure penicillium in  
flasks containing air and  having       
quantities of saccharine liquids equal  
to the quantities in the  small flasks  
of which we have been speaking1 the     
plant1 in consequence  of the large     
volume of air at its disposal1 will     

develop vigorously1 and  in the course  
of even a few days will have become     
perceptibly heavier4  ,in distilling the
 subjacent liquid1 however1 we shall    
generally find  that it contains no     
alcohol at all1 even though the weight  
of the plant  be half a gramme1 or more 
7#f or #g grains74    ,these results    
apply to all the fungoid growths that we
 have studied1 but  they vary           
considerably with the nature of the     
organisms4 ,aspergillus  glaucus is1 in 
this respect1 one of the most curious4  
,on ,june #aeth1 #ahgc1 we impregnated  
three flasks of wort1 ,a1 ,b1 ,c1 with  
pure spores of aspergillus glaucus4 ,the
 development was rapid and the          
fructification abundant4 ,on ,june      
#bjth1 we shook up the liquid and the   
supernatant fungoid growths in the three
 flasks2 the flasks ,a and ,b were  then
 treated as follows3--    ,we distilled 
the ,liquid in ,a to discover the       
presence of alcohol2 but  could find    
none4    ,illustration3 ,fig4 #ai4      

,the flask ,b was connected with a test 
flask 7,fig4 #ai71 into which the       
liquid1 together with its fungoid       
growth1 was transferred from ,b4 ,the   
next day1 ,june #bast1 the mycelium     
which was on the surface of the  liquid1
 in the neck of the flask1 was studded  
with bubbles of gas2 these  we dispersed
 by shaking4 ,on ,june #bbnd1 many      
others had formed again1 and  a large   
flake of mycelium that had risen from   
the bottom of the test  flask had been  
stopped at the bottom of the neck1 quite
 distended by gas  bubbles4 ,we         
liberated the gas by shaking1 but the   
bubbles formed again  by the next day1  
and this effect continued for several   
days2  nevertheless the liberation of   
gas was not continuous1 as is the case  
in  an ordinary fermentation4    ,on    
,july #bjth we drew off the liquid and  
distilled it2 it was still very  sweet1 
but though it contained a sensible      
quantity of alcohol1 the  microscope    
failed to detect a single cell of       

ordinary alcoholic ferment4    ,these   
results show that the aspergillus when  
in full growth1 with  plenty of air at  
its disposal1 does not yield alcohol1   
and that if we  submerge it1 so as to   
prevent the oxygen of the air from      
readily coming  into contact with its   
various parts1 it decomposes sugar1     
after the  manner of yeast1 forming     
carbonic acid gas and alcohol4    ,these
 effects were still more marked in the  
case of the flask ,c1 the  liquid in    
which1 after having been shaken up1 was 
not decanted to any  great depth in our 
test flask1 as had been the case with   
,b4 ,from ,june  #bast1 there was       
mycelium on the surface of the liquid1  
studded with  large bubbles of gas1     
which formed again after having been    
liberated by  shaking4 ,this last flask 
was examined on ,november #ast1 #ahgc4  
,its aspect  was unchanged2 the liquid  
was covered with mycelium loaded with   
sporanges and borne up by large old     
bubbles that had not disappeared4  ,the 

following was the analysis of the       
liquid3--                               
,alcohol           #ab                  
,glucose          #hdj                  
,dextrine 787     #cbj    ,the liquid   
was very bright1 and contained an       
amorphous granular deposit1  formed by  
the wort after it had been boiled1 at   
the time when we  prepared our flasks4  
,we crushed a small quantity of mycelium
 that had  risen to the surface of the  
liquid1 and obtained a field such as is 
represented in ,fig4 #bj4 ,amongst the  
ordinary filaments of mycelium          
belonging to the plant1 which are not   
represented in our engraving1 and  which
 were not more than #a_/cjj of a        
millimetre 7nearly #a_/gejj in47 in     
diameter1 we perceived much larger ones1
 swollen and contorted in the  most     
singular manner1 and measuring as much  
as #a_/ej of a millimetre  across their 
broadest parts4 ,there was also a       
multitude of the ordinary  spores of    
aspergillus mixed with others of larger 

size1 and big1  inflated cells1 with    
irregular or spherical protuberances1   
full of  granular matter4 ,as there are 
all the stages between the normal spores
  of the plant and the big cells1 and   
between these latter and the  filaments1
 it must be admitted that the whole of  
this strange vegetation  results from   
spores which change their structure     
under the influence of  special         
conditions to which they are exposed4#fb
 ,beyond all doubt these  cells and     
irregularly shaped segments1 in         
vegetating with difficulty1  gave rise  
to the fermentation1 which1 although    
insignificant1 was  sufficiently marked 
to produce more than a gramme 7#ae      
grains7 of  alcohol4 ,the oxygen of the 
air failing1 or existing in insufficient
  quantity for the regular development  
of the filaments of mycelium  belonging 
to the plant1 and for the germination of
 its submerged spores1  filaments and   
spores vegetated as the yeast of beer   
might have done if  deprived of oxygen4 

,illustration3 ,fig4 #bj4    ,if we     
study the vegetation of aspergillus     
glaucus with this  preconceived idea1 we
 shall soon recognize the fact that     
these spherical  forms of mycelium are  
the result of a greater or less         
deprivation of  air4 ,the filaments of  
this mycelium which develop freely in   
the aerated  liquid are young and       
transparent1 small in diameter1 and     
exhibit the  ordinary ramifications4    
,those which are situated about the     
centre1 in  the denser or more          
complicated parts1 to which the oxygen  
cannot  penetrate in consequence of its 
absorption by the surrounding parts1 are
  more granular in appearance as well as
 larger1 and inclined to develop        
swellings4 ,we can observe no conidia#fc
 on these filaments1 but we  may say    
that they are on the point of appearing1
 for the spherical  segments often tend 
to assume an appearance of close        
jointing1 as when  they take the form of
 those rows of swelling1 or cells1 which

 has given  rise to the idea of the     
chaplets of the conidia-cellules4 ,this 
is  represented in the accompanying     
sketches 7,fig4 #ba71 which we have     
purposely contrasted with two similar   
ones which relate to the mucor1  of     
which we shall soon speak4 ,the conidia 
of these latter are very  remarkable1   
and their fermentative character becomes
 apparent as soon as  their growths are 
deprived of air4    ,illustration3 ,fig4
 #ba ,a4 ,growth with abundant          
air-supply at the edge of  the mycelium 
crust4    ,illustration3 ,fig4 #ba ,b4  
,growth with reduced air-supply in the  
central  and deeper parts of the        
mycelium4    ,illustration3 ,fig4 #ba   
,c4 ,growth with abundant air-supply at 
the edge of  the mycelium tuft4         
,illustration3 ,fig4 #ba ,d4 ,growth    
with reduced air-supply in the central  
and deeper parts4    ,it is scarcely    
necessary to add that in these          
vegetations of  aspergillus1 which were 
accompanied by a corresponding alcoholic

  fermentation1 it was impossible to    
find cells of yeast2 and that1          
notwithstanding this1 the liquid was so 
adapted to ordinary alcoholic           
fermentation1 that1 when we added a     
small quantity of yeast to it1 in  the  
course of a few hours1 a most active    
alcoholic fermentation declared  itself4
    ,we may give some other facts       
relating to a crop of aspergillus       
glaucus  which was also grown in        
ordinary hopped wort1 and which was left
 to  itself for a year4    ,a two-necked
 flask1 holding #cjj c4c4 7rather more  
than #aj fl4 oz47 was  prepared and     
impregnated on ,december #bast1 #ahgc1  
and was then placed in  an oven at a    
temperature of #be ,c4 7#gg ,f474 ,the  
fungoid growth  developed in isolated   
tufts1 which subsequently united1 but   
without  entirely covering the surface  
of the wort4 ,a few tufts also vegetated
 at  the bottom of the liquid2 those on 
the surface soon became surrounded by   
large bubbles of gas4    ,on ,december  

#abth1 #ahgd1 we examined the liquid and
 the plant1 which for  a long time had  
appeared dead4 ,its mycelium was formed 
of aged1  granulated filaments1 with few
 swellings4 ,the weight of the dry      
fungoid  growth was #jej gramme 7about  
#h grains7 for a total volume of liquid 
of  #abb c4c4 7#d-a_/d fluid ounces74   
,we obtained #dd c4c4 of alcohol of #ae1
  which was about seven times the weight
 of the plant4 ,finally1 we  determined 
the acidity of the liquid1 and found #bh
 grammes1 in  equivalents of sulphuric  
acid1 a quantity greatly in excess of   
the total  acidity of an equal volume of
 wort1 a fact which shows us that       
fermentation caused by aspergillus      
glaucus is accompanied by the  formation
 of an organic acid1 the nature of which
 it would be  interesting to determine4 
,m4 ,gayon has commenced the study of   
this  subject in our laboratory4    ,in 
concluding our observations on the      
aspergillus glaucus1 we may give  the   
comparative results of two growths that 

were obtained under  precisely similar  
conditions1 in flasks of exactly the    
same size1 but  differing in this       
respect--that one of them was constantly
 subjected to a  current of pure air    
that played on the liquid4 ,in the      
course of a few  days1 when the fungoid 
growth in the flask that had been       
aerated had  attained a considerable    
size1 in comparison with the other1 we  
broke the  flasks in order that we might
 take out the two growths and compare   
their  weights4 ,after drying them at   
#ajj ,c4 7#bab ,f47 we found3--         
,growth in the aerated flask            
#jib               ,growth in the closed
 flask               #jaf               
,ratio of weights1 #ib_/af   #ege4      
,again1 although we had taken the       
precaution of condensing in a ,u tube1  
over which cold water played1 the       
vapours carried away by the current of  
air1 the liquid in the aerated flask    
gave no evidence of alcohol4 ,that  in  
the other flask contained a very        

appreciable quantity1 although the      
weight of fungoid growth in that flask  
was scarcely a sixth part of what  it   
was in the other4    ,the preceding     
facts taken altogether1 seem to us to   
demonstrate once  more1 in the most     
conclusive manner3--    ,firstly1 ,that 
neither penicillium nor aspergillus     
glaucus can change  into yeast1 even    
under conditions that are most          
favourable to the life  of that ferment4
    ,secondly1 ,that a fungoid growth   
which vegetates by using the oxygen of  
the air1 and which derives from the     
oxidating action of that gas1 the  heat 
that it requires to enable it to perform
 the acts necessary to its  nutrition1  
may continue to live1 although with     
difficulty1 in the  absence of oxygen2  
that1 in such a case1 the forms of its  
mycelian or  sporic vegetation undergo a
 change1 the plant1 at the same time1   
evincing a great tendency to act as     
alcoholic ferment1 that is to say1      
decomposing sugar and forming carbonic  

acid gas1 alcohol1 and other  substances
 which we have not determined1 and which
 probably vary with  different growths4 
,such1 at least1 is one interpretation  
of the facts that we have  reviewed4    
,the observations in the following      
paragraphs and chapters may  the more   
incline our readers to accept it as the 
true one4       ,,ii4--,growth of       
,mycoderma ,vini in a state of          
,purity--,confirmation of our  original 
,conjectures as to the cause of         
,fermentation--,mycoderma ,vini does    
not ,change into ,yeast1 although it may
 give rise to ,fermentation4      ,the  
efflorescence of wine1 cider1 and beer  
is pretty generally  known4#fd          
,fermented liquors cannot be exposed to 
the air without soon  becoming covered  
with a white film1 which grows thick and
 becomes  wrinkled in a marked manner in
 proportion as it is deprived of room   
wherein to spread horizontally1 in      
accord with the extraordinary           
multiplication of the cellules that     

compose it4 ,the rapidity of this       
multiplication is sometimes astounding4 
,during the heat of summer1 when  the   
medium is well adapted to the life of   
the plant1 we may count the  number of  
cells which grow in the course of a few 
hours by millions4 ,the  absorption of  
the oxygen necessary to the activity of 
this growth1 and  the heat developed in 
the film1 as well as the liberation of  
carbonic  acid gas1 that result from it 
are considerable4 ,a piece of glass     
covering the mycoderma1 at some distance
 above it1 becomes wet with  moisture1  
that soon accumulates to form large     
drops of water4 ,the  quantity of oxygen
 absorbed is so great that we never see 
any other  fungoid growth on the surface
 of this film1 although the air is      
constantly depositing on it1 as dust1   
spores of an entirely different         
character2 for1 notwithstanding that the
 warm and moist surface is in  contact  
with an atmosphere that is being        
continually renewed1 yet the  mycoderma 

appropriates to itself all the oxygen   
contained in the air4  ,when1 however1  
the vegetation begins to languish1 we   
often find1 on the  other hand1 that the
 plant becomes associated with other    
species of  mycoderma1 notably mycoderma
 aceti1 as well as other fungi1 amongst 
which penicillium glaucum generally     
appears4 ,this is one of the facts      
which1 wrongly interpreted1 have led to 
the belief that mycoderma vini  or      
cerevisi may possibly1 or even readily1 
become transformed into  penicillium1   
and vice vers4#fe ,as the study of the  
growth of  mycoderma vini on the surface
 of saccharine liquids and in their     
depths1 unaccompanied by any other      
species1 has the most important  bearing
 on the theory of alcoholic             
fermentation1 we may pursue it  through 
a few examples with all the detail that 
it allows of4    ,illustration3 ,fig4   
#bb4    ,on ,june #bast1 #ahgb1 we sowed
 some mycoderma vini in three flasks1   
with  double necks1 ,a1 ,b1 ,c 7,fig4   

#bb71 containing some wort4 ,the spores 
employed for the purpose were obtained  
from plants growing on sweetened        
yeast-water in an ordinary closed flask4
 ,this had been impregnated with  spores
 from plants grown on wort1 which in    
turn had sprung from spores  taken      
directly from mycoderma vini growing on 
wine4    ,the several impregnations were
 effected by means of a platinum wire1  
held by forceps1 both having been first 
cleaned by passing through  flame1 and  
then smeared with the fungoid films4    
,by this series of growings in closed   
vessels1 which were but momentarily     
open at the time when we dropped the    
spores into them1 we secured the        
separation of the mycoderma from all    
foreign organisms2 and more             
particularly from germs of mycoderma    
aceti1 which is generally found  along  
with it1 but which propagates with      
difficulty in neutral  saccharine       
liquids4    ,on the following days films
 of mycoderma vini had spread over the  

surface of the liquid in the three      
flasks4 ,to all appearance they were    
very pure2 and the microscope showed the
 complete absence of any mixture  of    
mycoderma aceti1 lactic ferment1 or     
other foreign growths4#ff    ,on ,june  
#bfth we decanted and distilled the     
liquid in ,a without finding  any trace 
of alcohol4 ,we shook up the liquids in 
,b and ,c1 with all due  precautions1 so
 as to submerge their films as much as  
possible1 and then  we raised the       
temperature of the flasks to #bf ,c4 or 
#bh ,c4 7#hb ,f474  ,for some days      
afterwards we saw a constant succession 
of minute bubbles  of carbonic acid gas 
rising through the liquid1 which        
remained bright  under the part of the  
film that had not fallen in4 ,it had all
 the  appearance of a slow but          
continuous fermentation4    ,on ,june   
#bith we decanted and distilled the     
liquid in ,b1 and found in it  an       
appreciable quantity of alcohol1 which  
showed itself in the first              

distillation4 ,the flask ,c1 which was  
shaken afresh1 continued to give  signs 
of fermentation1 but1 some days later1  
the evolution of the  bubbles ceased4   
,on ,july #aeth1 #ahgc1 we examined the 
flask with its film and its deposit  of 
mycoderma vini1 without finding a trace 
of any foreign growths1  either in the  
shape of penicillium glaucum1 or mucor  
mucedo1 or  rhyzopus nigrans1 or        
mycoderma aceti1 or1 in short1 any of   
the  organisms which could not have     
failed to appear on the surface of a    
substratum so peculiarly adapted to     
their development1 had it been in  the  
nature of mycoderma vini to transform   
itself into one or other of  those      
common fungoid growths4 ,the liquid1    
moreover1 still remained  sweet1 and did
 not contain any cells of actual yeast4 
,we may conclude  then that when one or 
more of these fungi occur1 after an     
interval of  some days1 in a growth of  
mycoderma vini conducted in contact with
  common air1 it does so in consequence 

of that air having1 without the         
knowledge of the observer1 impregnated  
the liquid spontaneously with  germs of 
these foreign organisms4    ,there might
 perhaps be room for some fear that the 
conditions of growth  in our flasks were
 not favourable to the simultaneous     
appearance of  these common fungoid     
growths along with the mycoderma vini4  
,on ,june  #bdth1 #ahgb1 we sowed1 in   
three flasks of sugared yeast-water1    
prepared  as before--in the first1      
mycoderma vini1 together with           
penicillium  glaucum2 in the second1    
mycoderma vini1 together with mucor     
mucedo2  in the third1 mycoderma vini   
alone4    ,we effected this by plunging 
the platinum wire1 which we used for    
impregnating the liquids1 into the pure 
film of mycoderma vini1 and  then       
touching with the wire the sporanges of 
the other fungus4 ,on ,june  #bith1 we  
saw on the surface of our first flask   
some green patches of  penicillium1     
along with some spots of mycoderma vini2

 in the second  flask a voluminous      
mycelium of mucor mucedo1 distended by  
large  bubbles1 had risen to the surface
 of the liquid1 and was entirely        
covered by a film of mycoderma vini4 ,as
 for the liquid in the third  flask1    
there were only a few spots of very pure
 mycoderma vini4 ,this  last flask1     
after being kept in an oven at #be ,c4  
7#gg ,f47 for several  months1 still    
contained nothing but mycoderma vini1   
unmixed with any  other fungoid growth  
whatever4    ,we may therefore be sure  
that mycoderma vini1 vegetating on the  
surface of liquids adapted to its       
nutrition1 in contact with air  deprived
 of its germinating dust1 will not      
present the least sign of a             
transformation into any of these other  
common fungi1 or into yeast1  however   
long may be the duration of its exposure
 to contact with that  pure air4    ,we 
may now return to that feeble and       
limited production of carbonic acid  gas
 and alcohol1 the formation of which we 

have shown experimentally to  take place
 at a high temperature1 after submerging
 the film of  mycoderma vini4#fg ,there 
can be no doubt that we have here a     
phenomenon similar in every point to    
that presented by penicillium and       
aspergillus1 which we studied in the    
preceding paragraph4 ,when the  germs or
 jointed filaments of mycoderma vini1   
growing on a saccharine  substratum in  
contact with the air1 are in the full   
activity of life1  this activity is     
carried on at the expense of the sugar  
and other  materials in the liquid1 in  
the same way that animals consume the   
oxygen  of the air and evolve carbonic  
acid4    ,the consumption of the        
different materials is attended with a  
proportionate formation of new          
materials1 development of structure1 and
  reproduction of organisms4    ,under  
these conditions1 not only does the     
mycoderma vini not form a  sufficiency  
of alcohol for analytical determination1
 but1 if any alcohol  exists in the     

subjacent liquid1 the mycoderma consumes
 it1 converting  it into water and      
carbonic acid gas1 by fixation of the   
oxygen of the  air4#fh ,if1 however1 we 
suddenly submerge the mycoderma1 we     
shall  obtain a different result4 ,if1  
on the one hand1 the conditions of life 
of this fungus are incompatible with the
 altered circumstances in which  it is  
placed1 the plant must perish1 just as  
an animal does when  deprived of oxygen4
 ,but if1 in spite of these changed     
conditions of  nutrition1 it can still  
continue in life1 we should expect to   
see marked  changes in its organic      
structure1 or chemical metamorphoses4   
,the result  of our observations points 
to the continuance of life1 in a        
distinct  though sluggish and fugacious 
activity1 accompanied by the phenomena  
of  alcoholic fermentation1 that is1 the
 evolution of carbonic acid gas1 and    
the production of alcohol4    ,if we    
take a drop of liquid charged with      
disjointed cells of  mycoderma1 a day or

 two immediately after the submersion of
 the film1  we shall observe changes1   
small but appreciable1 in the aspect of 
a  great number of these cells2 they    
will show increase in size1 their       
protoplasm will be in process of        
modification1 and many of them will     
have put forth little buds4 ,it will be 
quite evident1 however1 that  these acts
 of interior nutrition and the changes  
of tissue resulting  from them1 proceed 
with difficulty2 the buds when they form
 will soon  wither1 and there will be no
 multiplication of new cells4 ,these    
changes  will1 nevertheless1 be         
accompanied by the decomposition of     
sugar into  alcohol and carbonic acid4  
,in comparing these facts with those    
which we have pointed out in  connection
 with the cultivation of penicillium and
 aspergillus1 we  are compelled to admit
 that the production of alcohol and     
carbonic acid  gas from sugar--in one   
word1 alcoholic fermentation--is a      
chemical action1  connected with the    

vegetable life of cells which may differ
 greatly in  their nature1 and that it  
takes place at the moment when these    
cells1  ceasing to have the power of    
freely consuming the materials of their 
nutrition by respiratory processes--that
 is1 by the absorption of free          
oxygen--continue to live by utilizing   
oxygenated matters which1 like  sugar or
 such unstable substances1 produce heat 
by their decomposition4  ,the character 
of ferment thus presents itself to us1  
not as being  peculiar to any particular
 being or to any particular organ1 but  
as a  general property of the living    
cell4 ,this character is always ready to
  manifest itself1 and1 in reality1 does
 manifest itself as soon as life  ceases
 to perform its functions under the     
influence of free oxygen1 or  without a 
quantity of that gas sufficient for all 
the acts of nutrition4  ,thus we should 
see it appear and disappear             
concomitantly with that mode  of life2  
feeble and fugacious in its action when 

the conditions of this  vitality are of 
a similarly restricted character2       
intense1 on the other  hand1 and of long
 duration and productive of large       
quantities of  carbonic acid gas and    
alcohol1 when the conditions are such   
that the  plant or cell can multiply    
with facility in this novel manner4 ,to 
this  we may attribute all possible     
degrees of activity in fermentation1 as 
well as the existence of ferments of    
every variety of form and of very       
different species4 ,it may readily be   
imagined that sugar may undergo         
decomposition in a quite different      
manner from that of which we have       
spoken1 that instead of alcohol1        
carbonic acid gas1 glycerine1 and       
similar substances1 it may yield lactic1
 butyric1 acetic1 and other  acids4 ,it 
would be only one definite class of     
cellular organisms1 the  members of     
which resembled each other more or less1
 that decomposed  sugar into alcohol and
 carbonic acid2 others1 specifically    

different1  would act in a different    
manner4 ,in short1 we may say that the  
number of  these living organisms is a  
measure of the number of different      
ferments4    ,plate ,,iv4 represents in 
its two halves the condition of the     
mycoderma  vini at two different and    
unequal periods after its submersion4   
,in the  left-hand semi-circle1 it is   
evident that many of the figures are    
swollen1 that modification of their     
protoplasm has taken place1 and         
incipient budding is going on in several
 of them4 ,a budding of this kind  would
 not wither2 the buds would grow and1   
detaching themselves1 would  form new   
cells capable of budding in their turn4 
,we should have under  our eyes all the 
characteristics of a yeast1 which1      
beyond doubt1 would  give rise to a very
 active fermentation1 inasmuch as it    
would belong to  the order of phenomena 
of nutrition and vital energy of which  
we are  speaking4 ,instead1 however1 of 
insisting upon the acceptance of our    

interpretations1 based on a few facts   
merely1 let us go on to accumulate      
facts1 varying the conditions as much as
 possible4 ,our examples1 taken  singly1
 may seem insufficient to establish the 
theory that it will be  our endeavour to
 substantiate1 but taken together we    
trust that they  will secure our        
readers' confidence4    ,we may now1    
perhaps with advantage1 introduce two   
new expressions to  embody the preceding
 facts1 by the help of which we may     
often shorten  our subsequent           
explanations4 ,since life can continue1 
under certain  conditions1 away from    
contact with the oxygen of the air1 and 
since the  altered nutrition is         
accompanied by a phenomenon which is of 
great  scientific as well as industrial 
importance1 we may divide living beings 
into two classes1 arobian1 that is those
 which cannot live without  air1 and    
anarobian1 which1 strictly speaking1 and
 for a time1 can do  without it2 these  
latter would be ferments1 properly so   

called4 ,again1  since we can conceive1 
in an entire organism1 some organ or    
even a cell  capable of existing1 at    
least momentarily1 apart from the       
influence of  the air1 and endowed at a 
given moment with the character of a    
ferment1  we may1 in like manner1 make  
use of the expression anarobian cell1 in
  opposition to a cell that is arobian4 
,as long ago as #ahfc1 in our work on   
putrefaction1 we proposed to adopt  the 
preceding expressions1 and since then we
 have had the satisfaction  of seeing   
them used by different authors in       
,france and other countries4    ,one of 
the principal assertions in this        
paragraph relates to the                
non-transformation of mycoderma vini    
into other moulds or into  yeast4#fi    
,illustration3 ,plate #d4 ,mycoderma    
,vini functioning as an ,alcoholic      
,ferment4--,right ,half1 showing        
,appearance of ,spores just ,sown2 ,left
 ,half1  their ,appearance after an     
,interval of ,submerged ,life4    ,for a

 long time1 like ,turpin and many other 
observers1 although we had  no belief in
 the transformation of mycoderma vini   
into any one of the  common moulds1 yet 
we did believe in its transformation    
into alcoholic  ferment4 ,in the course 
of more elaborate researches1 however1  
we at last  discovered that our previous
 experiments had been vitiated from the 
same  source of error which we have so  
often had occasion to point out as      
affecting the observations of our       
opponents1 namely1 the fortuitous and   
spontaneous introduction1 unknown to the
 experimentalist1 of germs of  the very 
plant for whose appearance by way of    
transformation he is  seeking4    ,when 
we consider that every fermented vinous 
liquor1 when put on  draught1 is liable 
to efflorescence1 it is difficult to    
avoid the  supposition that this        
efflorescence is primarily due to cells 
of the  yeast that has caused the liquid
 to ferment1 from which cells the       
liquid could not be completely freed1 no

 matter how bright it might  have been1 
and which come to the surface of the    
liquid to live after  the manner of     
fungoid growths4 ,we wished to test this
 supposition by  means of experiments4  
,so great1 however1 was the resemblance 
between  the forms possible to yeast and
 mycoderma1 of which latter             
efflorescence is really composed1 that  
we quite despaired of being  able to    
solve the question by microscopical     
examination1 that is1 by  observing the 
actual conversion of a cell of yeast    
into a cell of  mycoderma4 ,in order1   
then1 to overcome that difficulty1 we   
endeavoured  to produce an inverse      
transformation--that of mycoderma into  
yeast4 ,we  imagined that we should     
doubtless obtain this result by         
submerging  some of the efflorescence of
 wine or beer in a saccharine liquid    
well  adapted to alcoholic fermentation4
 ,by submerging the mycoderma we  would 
do away with the ordinary conditions of 
life in this kind of  fungoid growth2   

for we would thus prevent the supply of 
oxygen from  the air1 since that oxygen 
would always be excluded1 in the most   
effectual manner possible1 by the       
portion of mycoderma that would  remain 
on the surface of the liquid1 even after
 the submersion  process2 and on the    
other hand1 we would be subjecting our  
growth to  the ordinary conditions of   
ferment life1 which acts at the bottom  
or  in the bulk of liquids fermenting4  
,our experiments were conducted in the  
following manner3--,in some flat        
porcelain basins1 we grew some pure     
mycoderma vini#gj on fermented  liquids1
 such as wine or beer1 or on            
artificially vinous liquids1 such  as   
alcoholized yeast-water1 taking care to 
boil these liquids previously  to kill  
any germs of yeast or other organism    
that they might contain4  ,the basins   
themselves1 as well as the plates of    
glass with which they  were to be       
covered1 were plunged into boiling water
 just before they  were wanted for use4 

,as soon as the film of mycoderma had   
become well  developed and thick1 and   
even wrinkled--a process requiring not  
more than  two or three days during     
summer heat--we decanted the subjacent  
liquid1  by means of a siphon1 so as to 
leave the film on the bottom of the     
basin4 ,we then diffused the whole mass 
of efflorescence in a saccharine  liquid
 that had been boiled and afterwards    
cooled down in a closed  vessel2        
generally1 we used wort or must         
preserved by ,appert's process4  ,after 
that1 we emptied the mixture of         
saccharine liquid and  efflorescence    
into long-necked flasks that had        
likewise been previously  heated1 as    
also had the funnels used in the process
 of transference4    ,it seemed to us   
that experiments conducted with all     
these precautions  must be free from    
causes of error4 ,it was true that we   
were working more  or less in contact   
with atmospheric air1 but all that we   
had to fear for  the soundness of the   

conclusions which we might draw was the 
presence of  germs of alcoholic ferment1
 and we considered how few of these     
there are  amongst floating particles of
 dust4 ,consequently1 if we succeeded in
  observing the advent of yeast in each 
of the long-necked flasks1  accompanied 
by an active alcoholic fermentation1 we 
thought that we  might1 without danger  
of error1 admit as a fact the           
transformation of  cells of mycoderma   
into cells of yeast4 ,again1 we thought 
that we should  probably find in the    
forms of the cells of yeast which were  
directly  derived from the cells of     
mycoderma1 a more or less elongated     
structure1  which would be a convincing 
proof of the transformation that we were
  seeking1 if1 indeed1 such             
transformation were possible4           
,strange to say1 everything happened in 
a manner that seemed to realize  our    
expectations4 ,the saccharine worts in  
the flasks in which we had  mixed and   
submerged the mycoderma1 fermented in   

the course of a few  days2 the yeast    
first appeared in elongated shapes2     
lastly1 we could see  under the         
microscope that many of the cells or    
jointed filaments of  mycoderma were    
inflated and presented the appearance of
 undoubted  gradations between their    
natural state and that of the cells of  
yeast  which soon formed part of the    
deposit in the vessels4 ,in spite of all
  this1 however1 we were the victims of 
an illusion4    ,in experiments         
conducted as we have just described1 the
 yeast which  appears1 and which soon   
sets up an active alcoholic             
fermentation1 is  introduced in the     
first place by atmospheric air1 from    
which germs are  constantly falling     
either upon the film of mycoderma or    
upon the objects  that are employed in  
the successive manipulations4 ,two      
peculiarities in  these experiments     
first opened our eyes to the existence  
of this cause  of error4 ,we sometimes  
found at the bottom of the flasks in    

which we had  submerged the             
efflorescence1 along with the cells of  
mycoderma1 large1  spherical cells of   
mucor mucedo or racemosus1 ferment-cells
 that we  shall soon learn to recognize 
in studying this curious fungoid growth4
  ,the existence of mucor mucedo or     
racemosus1 where we had only sown       
mycoderma vini1 was to us a proof that  
one or more spores of that  mucor had   
been introduced by the surrounding air4 
,if then1 we reasoned1  the air can     
introduce spores of mucor into our field
 of operations1 why  should it not      
introduce cells of yeast1 especially in 
our laboratory8  ,again1 it sometimes   
happened that a negative result was     
obtained4  ,harassed by doubts about the
 reality of this transformation1 which  
accorded so well with1 the physiological
 theory of fermentation we had  been led
 to adopt1 we repeated the experiments  
many times1 and in some  cases we failed
 to detect any appearance whatever of a 
transformation of  mycoderma into yeast 

cells1 although the conditions under    
which each of  the experiments was      
conducted had been as similar as could  
be4    ,we were at a loss to account for
 this inactivity in the cells of the    
mycoderma4 ,even in the most favourable 
cases of the supposed  fermentation1 it 
was evident that a host of cells of     
mycoderma vini  did not become cells of 
yeast2 but how could it possibly be     
admitted  that amongst the millions of  
submerged cells1 none were adapted for  
transformation1 if that transformation  
were at all possible8    ,thereupon1 to 
find a way out of the difficulty1 we    
resolved to modify  completely the      
conditions of our experiments1 and to   
apply to the  research that we had in   
view a mode of cultivation that might   
completely1 or nearly so1 obviate the   
sole cause of error that we  suspected1 
namely1 the possible fall of cells or   
germs of yeast during  the              
manipulations4 ,we secured this by the  
use of flasks with two tubes1  the right

 hand one of which was closed by means  
of a piece of  india-rubber tubing with 
a glass stopper1 the other one being    
drawn out  in the shape of a swan's     
neck4 ,the use of these flasks1 which   
was then  new to us1 permitted us to    
grow mycoderma and to study it under the
  microscope without fear of disturbance
 from exterior particles of dust4  ,this
 time we obtained the results given in  
the first part of this  paragraph4 ,we  
no longer observed yeast or alcoholic   
fermentation  following the submersion  
of the efflorescence1 either in the     
flasks  themselves1 or in the           
test-flasks attached to them1 as        
represented in  ,fig4 #ai4 ,we observed1
 however1 that kind of alcoholic        
fermentation of  which we have already  
spoken and which is due to the mycoderma
 itself1 a  fermentative action that is 
still more instructive than the one     
which we  thought we had determined1 and
 certainly not less calculated to       
support  the theory of fermentation     

which we have already briefly sketched4 
,in an age when ideas involving         
transformation of species are so readily
  accepted1 perhaps in consequence of   
their requiring no rigorous             
experimental work1 it is not without    
interest to consider that1 in the       
course of our researches upon the       
growths of microscopic plants in a      
state of purity1 we once were inclined  
to believe in the transformation  of one
 organism into another--the             
transformation of mycoderma vini or     
cerevisi into yeast1 and that1 on that  
occasion1 we were altogether  wrong1    
through having ourselves fallen a victim
 to the identical source  of error which
 confidence in our theory of germs had  
led us so  frequently to detect as      
affecting the observations of others4   
,,iii4--,growth of ,mycoderma ,aceti in 
a ,state of ,purity4      ,the study of 
mycoderma aceti has not escaped the     
numerous causes of  error which are apt 
to attend all observations made on      

microscopic  organisms4 ,this little    
fungus is still believed by many authors
 to be  one of those polymorphous       
species capable of great modifications1 
according to the conditions of their    
cultivation--it could be1 in turns1     
bacterium1 vibrio1 yeast1 c4 ,respecting
 it1 we have seen resuscitated  under a 
modern name1 in the course of the last  
few years1 the old  hypothesis of       
,buffon concerning organic molecules1   
that of ,turpin  concerning the         
punctiform globulines of barley1 milk1  
and albumen1 and  the theory maintained 
by ,dr4 ,pineau1 of ,nancy1 and by      
,pouchet concerning  proliferous        
pellicles4#ga    ,m4 ,bchamp1 ,professor
 in the ,faculty of ,medicine at        
,montpellier1  disdaining to adopt the  
expressions which we have just used1 has
  substituted for them that of          
microzyma1 whilst adhering to the       
opinions and errors represented by the  
other expressions4 ,this savant         
designates under the name of microzyma  

all those punctiform globulines  that   
are met with in most organic liquids    
when submitted to the  microscope2 and  
attributes to them1 with ,turpin1 the   
faculty of playing  the part of         
ferments1 as well as of transforming    
themselves into yeast  and various other
 organisms4 ,they are contained in milk1
 blood1 eggs1  the infusion of barley1  
and such like2 nay1 we may even find    
them in  chalk1 and so we have the fine 
discovery of ,microzyma cretae as a     
distinct species6    ,those who1 like   
ourselves1 cannot see in these          
granulations of organic  liquids ought  
besides things whose nature is still    
undetermined1 term  them molecular      
granules1 or1 in reference to their     
,brownian movements1  mobile granules4  
,indefinite expression is the best      
exponent of  imperfect knowledge2 when a
 precise terminology is invented1       
without any  basis of precise ideas     
derived from a rigid observation of     
facts1 sooner  or later the hypothetical

 facts disappear1 but the terminology   
prematurely created to explain them1    
hangs about the ,science1 and1  bearing 
an erroneous interpretation1 retards    
rather than promotes real  progress4    
,we may here introduce a summary of     
,turpin's system1 as given by himself4  
,it forms a complete biogenesis1 which  
leaves far behind it ,m4 ,bchamp's      
theory of microzymata1 ,m4 ,fremy's     
descriptions of hemi-organism1 and  ,m4 
,trcul's account of the genesis of      
bacteria and lactic ferment3--    8,when
 a mucous substance presents nothing    
visible through the  microscope1 as1 for
 example1 gelatinous matter1 dissolved  
gum1 the white  of eggs1 or plant-sap1  
simply thickened on its way to cambium1 
we call  it organic matter or           
organizable matter4 ,we attribute to it 
the  fecundating power of organic life  
in the simplest degree2 we consider it  
as material still isolated from         
organization4 ,we suppose that the      
invisible molecules1 of which this      

organizable matter is composed1 come    
together1 combine and serve through this
 association in the construction  of the
 different elementary forms of future   
tissues4    8,may we not with greater   
truth believe that organizable matter is
 of  varied origin1 formed of           
innumerable globulines1 too minute and  
transparent as yet to be observed by our
 present microscopical means1  and that 
these globulines which are always       
endowed with motion and a  special vital
 centre1 are all capable1 although many 
of them do abort1  of separate          
development either into a formative     
element of tissue or  into a mucedinous 
plant8    8,organizable matter may1     
according to its successive states of   
development or age1 and according to the
 different forms it takes in the        
tissues1 be distinguished by special    
names3--    8#a4--,we may term matter   
organizable as long as the globulines   
composing  it are not yet visible to    
microscopes of existing power4          

8#b4--,we may speak of amorphous or     
globuline tissue when even the          
globulines1 previously invisible1 have  
increased so as to be seen under  the   
microscope1 the term amorphous1 or      
shapeless1 being here applied to  the   
association of globulines1 and not to   
the globulines themselves4              
8#c4--,then we have vesicular tissue1   
when the globulines1 continuing to      
increase1 have developed in such a      
manner as to present a mass of          
continuous vesicles1 still empty or     
already containing a new generation  of 
globulines4    8#d4--,lastly we have    
filamentous or tubular tissue1 when the 
globulines1 instead of vesiculating1    
form threads or tubes40#gb    ,such are 
the purely hypothetical and exploded    
ideas which ,,mm4 ,fremy1  ,trcul1      
,bchamp1 ,h4 ,hoffmann1 ,hallier1 and   
others would revive in our  own day1 in 
opposition to a theory so clear and so  
well supported by  facts as that of     
germs floating in the air1 or spread    

over the surface  of objects1 as fruits1
 dry or green wood1 and so on4    ,m4   
,bchamp believes that he has discovered 
that mother of vinegar1  introduced into
 various saccharine liquids1 in the     
presence of carbonate  of lime1         
generates bacteria1 which1 with the     
sugar or dregs1 produce  butyric1       
lactic1 and acetic acids1 and that this 
same mother of vinegar1  without the    
addition of the carbonate of lime1      
8generates1 on the other  hand1 the fine
 cells1 which produce the normal        
alcoholic fermentation of  cane sugar40 
,further1 ,m4 ,bchamp advances the      
hypothesis that mother of  vinegar is a 
conglomeration of microzymata1 and1 as  
he fails to see in  the experiments on  
which he bases the conclusions which we 
have just  given1 that bacteria and     
ferment cells are the result of         
spontaneous  impregnation1 having no    
connection with the presence of mother  
of  vinegar1 on which he experimented1  
he arrives at this conclusion3 8,in  the

 experiments which ,i have just         
described1 things happened as though    
the microzyma1 under some peculiarly    
favourable conditions1 had been the     
parent both of the bacteria and the     
cells40#gc 444    ,the object of the    
following experiments was the study of  
these assumed  transformations of the   
mycoderma aceti in saccharine liquids1  
in the  presence and in the absence of  
carbonate of lime4    ,we prepared some 
two-necked flasks1 containing as a      
growing medium a  liquid composed of    
one-third of ,orleans vinegar1 and      
two-thirds of a  white wine used by     
vinegar-makers in ,orleans4 ,this liquid
 is peculiarly  adapted to the          
development of mycoderma aceti4    ,on  
,december #acth1 #ahgb1 we sowed the    
little plant in a state of purity1  by  
means of a piece of platinum wire1 in   
the manner already explained in         
connection with propagation of other    
fungoid growths4 ,on ,december #aith a  
young and thin film of mycoderma aceti  

covered the surface of the  liquid4 ,we 
then poured out the liquid through the  
right-hand tube1 at  the same time      
heating the end of the bent tube1 to    
purify the air that  passed into the    
flask4 ,the whole film of mycoderma     
aceti remained  adhering to the interior
 sides of the flask during this         
decanting4 ,the  question then was how  
to convey this film of the little plant 
into a  saccharine liquid of a          
particular kind4 ,we effected this      
easily by the  following means3 ,after  
having emptied the flask1 as just       
described1  instead of re-closing the   
india-rubber nozzle on the end of the   
right-hand tube1 we attached it to a    
test-flask containing the  saccharine   
liquid on which we wished to operate4   
,this had been  previously boiled in the
 test-flask1 and when we attached the   
neck of  the test-flask1 previously     
slightly drawn out and curved1 to the   
india-rubber tube1 the liquid was still 
very warm4 ,we permitted the  liquid in 

the test-flask to cool down1 and1 then1 
taking up the  test-flask1 we decanted  
its contents into the other flask1 in   
which1 as  we have already said1 the    
film of mycoderma aceti had been left4  
,in  this way the film became partly    
submerged1 partly spread over the       
surface of the new liquid4 ,experiments 
were made with two saccharine  liquids1 
must and wort4 ,in the case of the      
latter1 from ,december #bbnd  the whole 
surface of the liquid was covered by a  
film of mycoderma  aceti1 which even    
spread up the moist sides of the flask  
above the  level of the liquid4 ,in the 
case of the must1 on the other hand1 the
  plant for some time did not seem to be
 developing2 on ,december #bdth1        
however1 it was visibly spreading over  
the surface of the must4 ,the  following
 days we frequently shook up the films  
to separate them1 and  spread them over 
the subjacent liquid4 ,there were no    
signs of alcoholic  fermentation4    ,on
 ,december #cjth we introduced several  

grammes 7#ej or #fj grains7 of          
carbonate of lime into each of the      
flasks1 an operation of little          
difficulty1 which we effected in a      
manner similar to that just  described4 
,we substituted for the test-flask      
another flask--or1 better  still1 a     
simple glass tube--containing carbonate 
of lime that had been  subjected to     
great heat in the flask or tube1 and    
there left to cool  down4 ,when cold1 we
 poured the powdered carbonate of lime  
into the  liquid in the flask1 in this  
way avoiding the possibility of any     
error  from the introduction with the   
carbonate of lime of any foreign germ4  
,in neither case did we obtain alcoholic
 fermentation1 nor was there any        
appearance of lactic fermentation1 or   
bacteria1 or vibrios1 properly  so      
called4 ,the flasks remained in the     
oven1 at a temperature of about  #be ,c4
 7#gg ,f471 until the end of ,january1  
#ahgc1 when we made a  microscopical    
examination of their deposits1          

exercising greater care and  precaution 
than we had adopted in the case of those
 examinations which  we had made from   
time to time in the course of the       
experiment to assure  ourselves of the  
nature of the organisms present4#gd ,the
 result was  that we never found        
anything besides the mycoderma aceti1   
which had  developed1 although with     
great difficulty1 on the surface of the 
liquids  neutralized with carbonate of  
lime4 ,the beaded filaments had1 under  
these circumstances1 only become a      
little larger than they had been in  the
 unsweetened acid liquids4    ,mycoderma
 aceti1 then1 grown on sweetened acid or
 neutral liquids1  grown in the absence 
or in the presence of carbonate of lime1
 undergoes  no transformation into      
bacteria or vibrios or yeast1 if only we
 operate  with pure germs1 free from the
 dust floating in the air1 and from that
  which1 unknown to the operator1 may be
 introduced by means of the  vessels and
 materials employed4 ,it may be asked1  

do we1 therefore1  absolutely1 reject   
the theory of the polymorphism of       
mycoderma aceti8  ,on the contrary1 we  
have endeavoured to prove the existence 
of this  polymorphism again and again in
 a variety of ways4 ,we have been mostly
  concerned with physiological          
polymorphism2 that is1 our efforts have 
been directed to ascertain if mycoderma 
aceti might be1 for example1  the       
arobian form of a ferment from which it 
differed physiologically1  as1 for      
instance1 lactic ferment1 which1 in     
shape1 sometimes bears a  striking      
resemblance to mycoderma aceti4 ,we have
 not succeeded in  discovering anything 
of the kind up to the present time4     
,what1 in view of the positive proofs to
 the contrary1 we do absolutely  reject 
in the matter of this mycoderma1 is the 
theory of polymorphisms1  advocated by  
,m4 ,bchamp and other authors1 which1 in
 our judgment1 can  only be founded on  
incomplete and erroneous observations4  
,,iv4--,growth of ,mucor ,racemosus in a

 state of ,purity--,example of ,life    
more active and lasting when removed    
from the influence of ,air4      ,side  
by side with the facts explained in the 
last paragraph1 the study  of varieties 
of the genus mucor1 grown in natural or 
artificial  saccharine liquids1 is of   
great importance to the establishment of
 the  physiological theory of           
fermentation1 which we shall explain    
later on4  ,there is a very remarkable  
work on the subject of this mucedinous  
fungus  by a ,german botanist1 ,m4      
,bail1 who1 in #aheg1 declared that     
mucor  mucedo caused alcoholic          
fermentation1 and could change into     
ordinary  yeast4 ,the first assertion1  
relating to the alcoholic fermentation  
that  this fungoid growth which is      
everywhere so abundant may cause1 is    
quite  correct2 the second which relates
 to its faculty of changing into yeast  
is erroneous4#ge    ,on ,june #acth1    
#ahgb1 we sowed by the help of a        
platinum wire in some  wort1 contained  

in two-necked flasks1 ,a1 ,b1 and ,c1   
several of the minute  sporange-bearing 
filaments of mucor along with the heads 
containing  the spores4    ,on ,june    
#adth1 there was no mycelium visible to 
the naked eye in the  liquids4    ,on   
,june #aeth mycelium was very abundant1 
and was borne up by bubbles of  gas4 ,in
 addition to this there were a few      
scattered patches of bubbles  on the    
surface of the liquid1 showing that     
fermentation had commenced4    ,on ,june
 #afth fermentation continued to show   
itself by the frothy state  of the      
crusts of mycelium buoyed up by the     
bubbles of gas4    ,on ,june #agth we   
attached ,b and ,c separately1 as       
indicated in ,fig4 #ai 7p4  #aja7 to    
test-flasks1 into which we transferred  
nearly all their  contents4 ,some       
clusters of entangled filaments of      
mycelium remained on  the surface of the
 liquids in the test-flasks4    ,on     
,june #ahth a very slow fermentation    
commenced in the test-flasks2 it        

continued for some days without becoming
 more active4 ,a little bubble  would   
slowly rise from the bottom of the      
vessel1 succeeded after a short         
interval by another1 and so on4 ,the    
temperature of the oven was #bd ,c4     
7#ge ,f474 ,on ,june #bbnd we raised it 
to #bh ,c4 7#hb ,f474 ,the fermentation 
became more rapid1 a constant succession
 of bubbles rose quickly from  the      
bottom of the test-flasks2 still there  
was none of the vivacity of  an         
alcoholic fermentation produced by      
yeast4    ,on ,june #beth the           
fermentation was in much the same       
condition1 if  anything rather less     
active4    ,on ,june #bhth temperature  
#be ,c4 7#gg ,f72 fermentation had      
stopped4    ,on ,june #bith we raised   
the temperature to #bg ,c4 7#ha ,f47    
again1 and  some slight revival of      
fermentation manifested itself4    ,the 
increase in temperature1 therefore1 as  
might have been expected1  exercises a  
considerable influence on this kind of  

fermentation4    ,the vessels were then 
left to themselves1 and during the      
course of three  months they did not    
show the least sign of fermentation2    
moreover1 we  did not observe1 either on
 the interior walls of the empty flasks1
 or on  the surface or throughout the   
body of the liquid in the test-glasses1 
any fungoid production or organism      
whatever different from mucor  itself4  
,the same observations apply to the     
vessel ,a2 in this case the liquid  that
 remained in the flask was covered with 
a gelatinous and frothy  mycelium4      
,on ,october #bjth1 #ahgb1 after a lapse
 of three months and a half1 we  poured 
the liquid from the test-flask attached 
to flask ,c back again to  that flask4  
,the test-flask connected with flask ,b 
we left untouched  alongside the other  
flasks to serve as a means of           
comparison4    ,on ,october #bast1      
#bbnd1 #bcrd1 we observed nothing2 on   
succeeding days1  however1 some patches 
of bubbles appeared on the surface of   

the liquid  in flask ,c1 and clusters of
 mycelium buoyed up by the bubbles of   
gas  which they imprisoned4 ,life had   
resumed its course1 and with life       
fermentation had recommenced4 ,what had 
been the cause of this change in  the   
condition of the liquid1 after an       
absolute quiescence of three  months8   
,there can be but one answer to this    
question3 for in the other  vessels     
there was no corresponding movement1 or 
sign of life to be  detected4 ,in this  
vessel1 however1 an aeration of the     
plant had  evidently taken place1       
consequent on the decantation and       
contact with  the atmosphere of the     
flask1 which communicated with the      
exterior air  through the curved tube4  
,this aeration had been absent or       
ineffective  before decantation1 in     
consequence of the great depth of liquid
 in the  test-flask1 the surface of     
which1 too1 was covered by a mass of    
mycelium  filaments1 itself effectually 
opposing any aeration of the liquid4    

,moreover1 the surface of the liquid in 
the narrow neck of the test-flask  had  
necessarily been covered by a layer of  
carbonic acid gas4 ,we may  investigate 
more thoroughly the influence of        
aeration1 and its relation  to the      
resumption of life in the mycelium of   
mucor1 by restoring the  liquid to its  
previous condition of depth and so      
cutting off again  contact with the air4
    ,for this purpose1 on ,october #cast
 we decanted once more the liquid and   
its deposit from the flask into the     
test-glass4 ,the same evening a  slight 
but continuous fermentation1 with       
formation of froth1 appeared on  the    
surface of the liquid in the neck of the
 test-glass4 ,fermentation  although    
never vigorous1 continued the following 
days1 and until  ,december #bjth4       
,between ,december #bjth and #bcrd1 it  
ceased altogether to manifest itself  by
 liberation of gas4 ,as for the flask   
,b1 during all this time it had         
remained quite inactive and in the same 

state in which it had existed  since    
,june #bith1 although the oven had on   
several days been heated to  #bh ,c4    
7#hb ,f474    ,on ,december #bcrd1      
#ahgb1 wishing to assure ourselves of   
the state of the  plant in flask ,b1 we 
subjected it to the same operation to   
which the  flask ,c had been subjected  
on ,october #bjth3 that is to say1 we   
poured  the contents of the test-glass  
back into the connected flask1 with the 
object of supplying the plant with      
oxygen4    ,on ,december #bdth1 #beth1  
#bfth1 #bgth1 there was no apparent     
change4    ,on ,december #bhth bubbles  
of gas began to be evolved carrying up  
clusters  of mycelium to the surface of 
the liquid4 ,it was evident1 therefore1 
that the quiescence in the test-glass   
attached to flask ,b1 was solely  due to
 deprivation of air1 as had happened in 
the case of the test-glass  attached to 
flask ,c1 up to the date of ,october    
#cast4    ,on this day1 ,december #bhth1
 we re-decanted the contents of the     

flask  into the test-glass1 and the     
following day a continuous but feeble   
fermentation proceeded4 ,this lasted    
until ,january #bbnd1 although very     
sluggish in character2 it is evident    
that these effects were exactly the     
same as those which took place in flask 
,c4#gf    ,we should observe before we  
proceed further1 that we took specimens 
from  the flasks ,a1 ,b1 ,c1 at         
different times between ,june and       
,january1 and  that the microscope never
 revealed the least trace of yeast in   
them4 ,we  may note besides that1 during
 this interval1 we impregnated fresh    
flasks  of wort with specimens taken    
from the deposits in the flasks ,a1 ,b1 
,c1  and that we always obtained        
reproduction of the mucor and its       
peculiar  fermentation without the least
 appearance of ordinary ferment4    ,the
 inferences from the results that we    
have just detailed follow  readily1 and 
are besides of great interest4 ,in the  
first place1 it is  evident that even if

 the mucor mucedo may be able to produce
 alcoholic  fermentation1 it is totally 
incapable of changing into yeast4 ,the  
two  plants are necessarily and         
radically distinct1 and1 if different   
authors  have succeeded in obtaining    
them mixed one with another in growths  
of  mucor1 this intermixture was        
doubtless the result of a spontaneous   
sowing of the yeast1 the germs of which 
abound1 particularly in the  particles  
of dust existing in the atmosphere of   
any laboratory in which  studies        
relating to fermentation are pursued4   
,this1 however1 is not the most striking
 inference from the facts which  the    
cultivation of these organisms revealed4
 ,the mucor is evidently a  plant1 at   
the same time arobian and anarobian4 ,if
 we had sown the  spore-bearing         
filaments of mucor on slices of pear1   
lemon1 or similar  fruit1 we should have
 seen the spores germinate1 tubes of    
mycelium  ramifying on the surface of   
the substratum1 and reproducing         

sporiferous  aerial hyphae4 ,in this    
case the plant would have effected all  
its  phenomena of nutrition by absorbing
 oxygen and emitting carbonic acid1     
after the manner of animals1 as1 in our 
essay on the organic corpuscles  which  
exist in a state of suspension in the   
atmosphere1 we have shown to  be the    
case generally with fungoid growths4    
,under these circumstances1  the only   
sugar decomposed would have been a      
quantity equivalent to that  assimilated
 in forming the cellulose of the young  
tissues of the fungus1  or in entering  
into combination1 either with the       
elements of ammonia or  with the sulphur
 of the sulphates1 or the phosphorus of 
the phosphates1  to form the albuminous 
substances of the interior of the       
cells4#gg ,in  this case the sugar used 
up would furnish no alcohol1 or at      
least1 if  alcohol were formed1 it would
 be decomposed immediately4 ,all aerial 
growths take place in the same manner2  
and such is the nature of  nutrition and

 life in all the larger forms4    ,in   
our flasks1 on the other hand1 the life 
of the little plant functions  quite    
differently4 ,deprived of oxygen1 or    
having at its disposal but an           
insufficient quantity of that gas1 after
 a life of activity in contact  with    
air1 it can1 nevertheless1 live apart   
from the direct action of  that element1
 and the combinations to which it gives 
rise4 ,on the other  hand1 we see all   
the signs of alcoholic fermentation     
appear2 that is1 a  notable proportion  
of sugar1 in comparison with the weight 
of solid  matter assimilated and fixed  
by the plant1 is decomposed into alcohol
  and carbonic acid gas2 and this       
decomposition continues as long as life 
itself continues in the cells1 and they 
remain submerged1 this last  condition  
being effected by the decantation of the
 liquid and its  deposit into the       
test-glass4 ,along with the             
disappearance of the  phenomena of vital
 activity in the cells1 the fermentation

 ceases  absolutely1 or at least is no  
longer visible externally1 by reason of 
its extreme feebleness4 ,the cells then 
assume an old1 shrivelled1  worn-out    
appearance1 with irregular outlines and 
granular markings4  ,their life is      
merely suspended1 however1 not extinct2 
for if they be  supplied once more with 
oxygen1 and suffered to exist under the 
influence of that gas1 they will        
vegetate again1 and become capable of   
producing fermentation afresh1 even     
after having been excluded from the  air
 for a considerable time4    ,oxygen    
then presents itself to us as being     
endowed with a certain  determining     
stimulus in the matter of nutritive     
action enabling this  action to be      
prolonged beyond the point where the    
direct influence of  oxygen ceases4 ,in 
time the energy that has been imparted  
to the cells  will die away1 and then   
also fermentation will cease1 to be     
resumed1  however1 when the plant is    
once more submitted to the revivifying  

action  of the gas4 ,it seems as though 
the vital energy derived from the       
influence of gaseous oxygen were capable
 of effecting an assimilation of        
oxygen1 not in the gaseous state1 but   
existing in some state of  combination1 
and hence its power of causing the      
decomposition of sugar4  ,looking at the
 matter in this light1 it seems to us   
that we may discover  in it a fact of   
general occurrence1 that this peculiar  
action of the  oxygen and the cells is  
to be seen in all living beings4 ,for   
indeed is  there any cell which1 if     
suddenly and completely deprived of air1
 would  perish forthwith1 and           
absolutely8 ,probably there is not a    
single one  that would do so4 ,with     
certain modifications of greater or less
 amount  the assimilative and excretive 
acts which have taken place during life 
must be carried on after the suppression
 of oxygen1 resulting in  fermentations 
ordinarily obscure and feeble1 but in   
the case of the  cells of ferments1     

properly so called1 manifesting an      
activity both  greater in amount and    
more enduring4    ,let us now proceed to
 compare the weight of alcohol formed by
 the  mucor during fermentation with the
 weight of the plant itself4    ,first  
experiment4--,one of the double-necked  
flasks contained at  starting #abj c4c4 
7about #d fl4 oz47 of wort4    ,on      
,january #bnd1 #ahgc1 we attached this  
flask to a test-glass1 containing  a    
deposit of mucor ferment 7,fig4 #ai1 p4 
#aja71 a few drops of which we  poured  
into the wort in the flask1 to          
impregnate it4 ,on ,january #crd we     
decanted the wort from the flask into   
the test-glass2 under these  conditions 
we have seen that the wort must ferment4
    ,on ,january #ahth the fermentation 
in the test-glass ceased4 ,on ,july     
#cast1  #ahgc1 we transferred the liquid
 from the test-glass back to the flask4 
,on ,august #dth1 #ahgc1 we again       
decanted this same liquid from the flask
  into the test-glass4 ,on ,december    

#beth1 #ahgc1 we once more removed the  
liquid from the test-glass to the flask1
 and allowed it to remain so  until     
,december #bcrd1 #ahgd1 on which day we 
submitted it to examination4  ,it was   
found to contain per #ajj c4c4 7#c- fl4 
oz47                                    
,grains4   ,grammes4#gh        ,total   
weight of the fungus                    
#eg           #jcg        ,absolute     
alcohol                            #eji 
#cc        ,acidity1 estimated in its   
equivalent of      #ag           #jaa   
sulphuric acid        ,sugar1 determined
 by cupric solution        #hbb         
#eb        ,dextrine 787                
#bdf            #af    ,the total weight
 of fungoid growth being #jcg gramme1   
and the total  weight of absolute       
alcohol for the #abj c4c4 of fermented  
liquid being #d  grammes1 we had1       
consequently1 from ten to eleven times  
by weight more  alcohol than fungus4    
,second experiment4--,on ,june #acth1   
#ahgb1 we sowed two or three            

sporiferous heads of mucor in some wort 
contained in one of the  double-necked  
flasks4 ,the temperature of our oven    
varied between #bc ,c4  and #be ,c4 7#gc
 ,f4 to #gg ,f47 ,the total volume of   
liquid was #abj c4c41  as before4       
,june #aeth1 mycelium had developed1    
buoyed up on bubbles of gas4    ,june   
#afth1 patches of bubbles1 due to       
fermentation1 covered the surface  of   
the liquid4    ,june #agth1 we          
transferred the liquid to the           
test-glass4    ,june #bhth1 fermentation
 in the test-flask had ceased4    ,june 
#bhth1 fermentation recommenced1 the    
temperature of the oven being  raised to
 #bg ,c4 7#hj ,f474    ,october #bjth1  
the liquid was transferred back from the
 test-glass to the  flask4    ,october  
#bdth1 mycelium had developed1 supported
 by big bubbles on the  surface of the  
liquid in the flask4    ,october #cast1 
we retransferred the liquid to the      
test-glass4    ,november #ast1 a feeble1
 but continuous fermentation commenced4 

,this was  kept up until ,january #bnd1 
#ahgc1 on which day we transferred the  
liquid1  with its deposit from the      
test-glass to the flask1 when it now    
seemed to  be quite inert4 ,we left it  
in this flask until ,december #bdth1    
#ahgd1  without its manifesting during  
this long interval any sign of          
fermentation2 nor did the fungus appear 
to grow at all4    ,we then submitted   
the liquid to analysis1 and found in it1
 per #ajj c4c4--                        
,grammes4#gi        ,total weight of    
fungoid growth                          
#jbe        ,absolute alcohol           
#cd        ,acidity1 estimated in its   
equivalent of sulphuric          #jab   
acid        ,sugar1 determined by copper
 solution                        #fb    
,sugar1 determined after treatment by   
boiling with           #aj              
sulphuric acid1 and deduction of amount 
of sugar      already obtained          
7dextrine78    ,the total weight of     
absolute alcohol for the #abj c4c4 of   

fermented  liquid was #da grammes--that 
is1 the weight of the alcohol was       
sixteen or  seventeen times that of the 
plant4    ,illustration3 ,plate #e4     
,mucor1 ,vegetating ,submerged1 in      
,deficit of ,air4    ,the structure of  
the plant differs considerably when it  
lives surrounded  by air1 and when it is
 more or less completely deprived of    
that fluid4  ,if it has an abundance of 
air at its disposal1 if it vegetates on 
the  surface of a moist substance or in 
a liquid in which the air held in       
solution may be renewed without being   
incessantly displaced by carbonic  acid 
gas1 we shall see it develop as an      
ordinary fungoid growth1 with a         
mycelium consisting of filaments more or
 less slender1 branching1 and           
entangled1 sending up from the surface  
of the liquid aerial organs of          
fructification4 ,this is the well-known 
form of vegetation of the common  mucor4
 ,on the other hand1 if we compel the   
mucor to live in a  saccharine liquid   

with insufficiency of air1 at least for 
some of its  parts1 the mode of         
vegetation will change completely1 as we
 have seen in  the case of penicillium1 
aspergillus1 and mycoderma vini when    
submerged1 but with this difference1    
that in the case of the mucor the       
changes in question1 and the activity of
 nutrition under these new  conditions1 
are much more marked than in the case of
 those other  organisms4 ,the spores    
grow larger and the filaments of        
mycelium which do  develop are much     
stronger than those in the normal plant4
 ,these  filaments put forth1 here and  
there1 other filaments which detach     
themselves and vegetate at the side of  
the others1 being terminated or         
interrupted by chains of large cells1   
species of spores which can live  by    
budding and reproducing cells similar to
 themselves or by elongating  into      
filaments4    ,plate ,v4 represents the 
living plant submerged at a little      
depth1 and  having1 consequently1 still 

at its disposal a certain quantity of   
air1  insufficient1 however1 to supply  
the oxygen needed for all the acts of   
nutrition4 ,in this case the mucor      
appears very different1                 
morphologically1 from what it is when in
 free contact with air4 ,here it  forms 
short filaments1 having a diameter      
double or triple that of the  filaments 
of the ordinary mycelium with branches  
and buds all over1 and  what is         
especially characteristic1 forming a    
network of chains of cells1  sometimes  
spherical1 sometimes oval or            
pear-shaped1 which are the actual       
spores4 ,these1 as soon as they are     
detached1 bud in their turn1 and        
reproduce either cells or branching     
tubes2 these cells or the chaplets      
which they form being known under the   
name mycelian spores or  conidia4 ,our  
plate gives these different aspects very
 correctly1 and  affords us a good idea 
of the luxuriant state of this          
remarkable  vegetation4    ,plate ,,vi4 

represents the plant living at a greater
 depth with less air1  expending1 by    
means of sugar as source of heat1 the   
energy which it  acquired in vegetating 
under the influence of the oxygen of the
 air4 ,the  filaments are fewer and     
older in aspect1 and the number of      
cellular  forms is proportionately      
larger than in the former case1 the     
budding  giving rise by preference to   
spherical or oval cells4 ,on a single   
cell  we often see two1 three1 four1    
five1 six1 and even more buds4    ,when 
the buds of the oval or spherical cells 
detach themselves whilst  young1 they   
often resemble in form and size cells of
 ordinary yeast1 nor  can even          
considerable experience in this kind of 
observation always  enable us to        
distinguish them4 ,hence we may easily  
understand how many  have come to       
believe1 with so skilful a botanist as  
,dr4 ,bail1 in the  transformation of   
mucor into yeast4    ,with the forms    
represented in ,plates ,v4 and ,,vi41   

the plant is more of a  ferment than of 
a fungoid growth4 ,in such cases the    
weight of sugar  decomposed in          
comparison with the weight of new       
cell-globules formed is  very           
considerable1 an effect which is more   
marked the less air the plant  has at   
its disposal4 ,under the latter         
conditions1 however1 vegetation is  slow
 and laborious1 and the ferment very    
soon assumes an aspect of age1  and we  
must constantly rejuvenate the cells by 
bringing them into  contact with oxygen1
 and subjecting them to the action of   
limited  quantities of that gas1 and so 
promote their vegetation and prolong    
their fermentative activity4 ,this      
effect we brought about when we         
retransferred the liquid and its deposit
 of mucor from the test-glass  to the   
flask1 thus bringing them into contact  
with fresh air4 ,we saw  cells that     
appeared old1 dark1 and highly          
granulated1 become inflated1  grow more 
transparent1 and fill with a gelatinous 

protoplasm1 the few  granulations which 
they still exhibited assuming a         
brilliant appearance  when we succeeded 
in distinguishing them2 and finally1 a  
very active  budding was set up4 ,under 
this reviving influence life could      
continue  once more away from the air1  
although with difficulty1 so that       
fermentation would be most intense if   
the large filaments and their  conidia  
were constantly being removed from and  
to the action of air4    ,the preceding 
plates show several instances of this   
rejuvenescence of  the old cells of     
mucor ferment4    ,illustration3 ,plate 
#f4 ,ferment of ,mucor4    ,we have     
omitted to represent amongst the old    
cells some cells which have  their      
granulations collected about the centre1
 with an empty space  between the       
granulations and the exterior           
borders4#hj ,in this state1  cells are  
generally dead and incapable of any     
revival4 ,it is impossible  to avoid    
being impressed by the striking         

analogies which exist between  all these
 facts and those presented by cells of  
yeast4    ,in concluding our study of   
the vegetation of mucor as a mould and  
mucor as a ferment1 we may again remark 
that the most striking  analogies also  
exist between the preceding observations
 and those we  have seen in the case of 
penicillium1 aspergillus1 and mycoderma 
vini4 ,these latter plants do not       
furnish alcohol or carbonic acid gas  by
 direct fermentation of the sugar1 as   
long as we let them vegetate  with      
plenty of air at their disposal4 ,once  
submerged1 however1 their  vital aspect 
changes2 on the one hand the cells or   
filaments of the  mycelia evince a      
tendency to become larger2 on the other 
hand there is a  tendency to greater    
closeness in these latter1 and1         
consequently1 a  transition to the state
 of conidia4 ,lastly1 there is a        
correlative  budding of cells1          
accompanied by a formation of alcohol   
and liberation  of carbonic acid gas2 in

 short1 all the ordinary signs of       
alcoholic  fermentation4    ,the        
principal difference in the case of     
mucor consists in this1 that  the       
vegetation of this latter1 under the    
conditions of insufficient  aeration or 
none at all1 is more decided1 both as to
 extent and  duration4    ,it may be    
thought that all the varieties of mucor 
are capable of  yielding the kind of    
ferment that we have just mentioned4    
,but this is  not the case2 and here we 
have another striking proof of the great
  physiological differences presented by
 forms of vegetation so intimately      
connected with each other that1 in      
botanical classifications1 they must  be
 put as closely as possible together4   
,of this fact we have the most  striking
 example in mycoderma vini and the      
alcoholic ferments1  properly so called1
 which so closely resemble each other in
 form and  development that they might  
be supposed to be identical1 at least1  
according to our present knowledge1 but 

which differ so widely in their         
physiological aspects4    ,on ,november 
#agth1 #ahgc1 we found a very beautiful 
specimen of mucor  mucedo on a pear1    
under a glass bell jar4 ,it was a mass  
of perfectly  straight filaments1 simple
 and isolated1 very large in comparison 
with  those ordinarily met with1 each   
terminating in a sporange1 identical to 
that of mucor mucedo1 and               
proportionately well developed4 ,we are 
able  to distinguish mucor racemosus    
from mucor mucedo only by the           
circumstance of its having on its       
sporange-bearing hyph lateral  branches 
which also terminate in sporanges4      
,we sowed only one of the terminal heads
 of the large erect hyphae in  some     
wort1 in which it soon produced an      
abundant mycelium1 but without  the     
least appearance of gas4 ,for a very    
long time1 up to ,january #gth1  #ahge1 
we studied the developments of this     
organism1 which remained all  the time  
perfectly pure1 in consequence of our   

having cultivated it in  one of our     
two-necked flasks on pure wort4    ,the 
total volume of liquid1 which was #acj  
c4c41 7#deg fl4 oz47 contained  #bc     
grammes 7#cec grains7 of alcohol4 ,in   
spite of this rather large  proportion  
of alcohol1 a clear sign of undoubted   
fermentation1 the plant  had yielded no 
conidia at all1 nor any cell-globules of
 ferment4 ,some  of the filaments1      
however1 were larger than the rest1 and 
exhibited  irregularly-shaped swellings1
 which in some cases were of enormous   
size4  ,whilst the natural mycelial     
filaments1 by which we mean the         
vegetating  part of mucor1 which were   
supplied with abundance of air1 only    
measured  #c_/dej of a millimetre#ha in 
diameter1 the filaments that had grown  
probably with an insufficiency of       
oxygen1 and performed the functions of  
ferment1 measured #h_/dej1 and the      
swellings as much as #cj_/dej of a      
millimetre in diameter1 as represented  
in ,fig4 #bd4    ,illustration3 ,fig4   

#bd4    ,in concluding this paragraph1  
we may mention a very able research on  
fermentation which we have lately       
studied1 the author of which1 ,dr4      
,fitz1 communicated it to the ,chemical 
,society of ,berlin in #ahgc4 ,in       
section ,,ii41 page #dh1 this author    
explains his observations in a manner   
conformable to our own views1 as may be 
seen from the following passage  of the 
memoir3--    8,in the presence of       
oxygen1 the ferment of mucor develops   
into a  mycelium and consumes the sugar2
 in the absence of oxygen1 on the other 
hand1 the spores develop into ferment of
 mucor1 that buds and  decomposes the   
sugar into the products of fermentation4
    8,the properties of mucor mucedo in 
a fermentable liquid1 in the  presence  
or in the absence of oxygen1 accord     
perfectly with the theory  of           
fermentation established by ,pasteur in 
#ahfa 7,comptes rendus de  l',acadmie   
des ,sciences1 t4 lii41 p4 #abfj74      
,according to this theory a             

fermentative fungus needs oxygen for its
 development2 if it finds any  free     
oxygen it utilizes the whole of it1     
assimilating one part of the  sugar and 
burning the other2 whilst in the absence
 of free oxygen1 the  fungus            
appropriates what it requires from the  
sugar40    ,footnote #di3      ,in the  
course of this work we shall combat1 by 
means of experimental    proofs which   
appear to us irrefragable1 the opinions 
which many    writers entertain on the  
subject of certain transformations of   
organisms--that of penicillium glaucum  
into ferment1 or mycoderma2    of       
bacteria into lactic ferment2 of ferment
 into vibrios2 of    mycoderma aceti    
into ferment1 and so on4 ,nevertheless1 
we shall    pronounce no a priori       
opinion on the question whether the     
inferior    organisms1 which will be the
 subject of this chapter1 and which     
include yeast and the ferments properly 
so called1 are perfect beings    in     
their habitual form1 or whether they are

 susceptible of    polymorphism4 ,it is 
with this reservation that we employ the
 word    autonomy4 ,if we claim         
polymorphism for any species1 we shall  
not do    so without furnishing proofs4 
,some organs detached from higher       
organisms1 and some beings in a certain 
phase of their existence1 may           
reproduce themselves under a special    
form1 with special properties1    when  
brought into media and under conditions 
that are unfit for the    production of 
the plant or animal under its other     
shape or ordinary    mode of            
reproduction4 ,modern ,science affords  
many examples of this1    and certain   
alcoholic ferments present us with      
analogous facts2 but to    wish to      
stretch these facts beyond their due    
significance1 and to    admit a         
polymorphism that cannot be proved1 in  
consequence of a belief    that it is   
possible1 or on the faith of confused   
observations1 is to    indulge in       
gratuitous assertion from a mere spirit 

of system4    ,footnote #ej3      ,see1 
on this subject1 the author's tudes sur 
le ,vinaigre1 ,paris1    #ahfh1 p4 #gf1 
note2 and especially tudes sur le ,vin1 
#bnd ,edition1    #ahgc1 p4 #ai4        
,footnote #ea3      ,some observations  
in the preceding chapter enable us to   
account for    the vast number of germs 
which are constantly falling on the     
surface    of everything4 ,we may here  
allude to the use we have made of       
flasks1    shaped as in ,fig4 #ag1 and  
holding from #bej c4c4 to #cjj c4c41    
which are    a third part filled with an
 organic liquid1 and are closed up when 
boiling4 ,they contain no air when cool1
 and are opened in series of    #aj1    
#bj1 c41 out of doors1 and closed up    
again immediately4 ,the air    rushes   
violently into the vacuum1 and thus we  
introduce about #bjj c4c4    of air1    
with all the particles of dust contained
 in that air1 into    each flask4 ,it   
has been proved that a certain number of
 these flasks    undergo change in the  

course of time1 the number of those     
changing and    the nature of their     
changes being in close proportion to the
 probable    number and nature of the   
floating germs able to develop in the   
particular nutritive liquid used4 ,if we
 work at great elevations1 far    from  
houses and the dirt of towns and        
inhabited plains1 as we did at          
,montanvert1 near the ,mer de ,glace1   
change will seldom occur4 ,the          
opposite will be the case if we work in 
a place like the living-room    of the  
little1 dirty1 ill-kept inn at          
,montanvert4 ,in a laboratory    where  
fermentation is studied we obtain       
certain kinds of germs which    often   
differ from those found in the air of   
the open country4 ,if we    desire to   
have organisms in all our flasks1 we    
have only to stir up    the dust on the 
ground or on surrounding objects at the 
moment when we    open the flasks4 ,this
 simple and easy experiment clearly     
shows us that    it is impossible for a 

field of sporanges of fungoid growth1   
existing    in an uncovered vessel or on
 the surface of a fruit1 to escape      
becoming mixed with germs that are      
foreign to the little plant2 in    other
 words1 the student who sows spores of  
penicillium1 which he    has collected  
from one place or another on a brush1   
exposes himself to    serious causes of 
error4    ,footnote #eb3      ,m4 ,jules
 ,raulin has published a well-known and 
remarkable work on the    discovery of  
the mineral medium best adapted by its  
composition to the    life of certain   
ordinary fungoid growths2 he has given a
 formula for    the composition of such 
a medium4 ,it is this that we call here 
8,raulin's fluid0 for abbreviation4     
,water                     #a1ejj       
,sugar ,candy                  #gj      
,tartaric ,acid                 #d      
,nitrate of ,ammonia            #d      
,phosphate of ,ammonia        #jf       
,carbonate of ,potassium      #jf       
,carbonate of ,magnesia       #jd       

,sulphate of ,ammonia        #jbe       
,sulphate of ,zinc           #jjg       
,sulphate of ,iron           #jjg       
,silicate of ,potassium      #jjg       
,j4 ,,raulin4 ,paris1 ,victor ,masson1  
#ahgj4 ,thse pour le doctorat4          
,footnote #ec3      ,if we do not wish  
to take the chance of procuring the pure
    penicillium by means of these       
spontaneous sowings1 effected by        
opening and then closing in the flame a 
certain number of flasks with           
drawn-out points1 we may utilize one of 
the flasks1 which1 having been    opened
 and closed again1 has notwithstanding  
developed no organized    forms1 as     
follows3--,we impregnate the contained  
liquid directly1 by    dropping into it 
from a metallic wire spores taken from  
any growth of    penicillium exposed to 
the common air2 and then from the new   
field    of sporanges formed by this    
sowing in the flask that has been       
re-closed1 we must1 later on1 take the  
pure spores that we require4    ,this   

method is quicker and almost as safe4   
,we should add that1 if we wish to use  
for our purpose spores of    penicillium
 from a closed flask1 in which the plant
 has fructified1    we must be careful  
not to leave the plant too long closed  
up4 ,a few    days after the sowing the 
growth of the fungus is arrested1 in    
consequence of all the oxygen being     
absorbed1 and its place being           
supplied by a mixture of carbonic acid  
and nitrogen2 and the spores1    if kept
 too long in this atmosphere1 will all  
perish4    ,footnote #ed3      ,to shake
 the liquid without danger of           
introducing exterior particles    of    
dust1 we apply the flame of the spirit  
lamp to the drawn-out neck    of the    
flask1 and close up the open end2 we may
 then shake our flask    without risk4  
,we must afterwards reopen the end of   
the drawn-out neck    for the purpose of
 re-establishing communication with the 
exterior    air4    ,footnote #ee3      
,the flask ,b was closed with the lamp  

in consequence of one of the    objects 
of these experiments being to test ,m4  
,trcul's experiments on    the          
transformation of penicillium into      
ferment4 ,strangely enough1    according
 to ,m4 ,trcul1 as we shall see later   
on1 the spores of    penicillium refuse 
to change into ferment1 if the vessels  
in which    they are sown are not       
8perfectly air-tight40    ,footnote #ef3
      ,bulletin de la ,socit            
,philomathique4    ,footnote #eg3       
,,hermann ,,hoffmann1 tudes             
,mycologiques sur la ,fermentation4     
,botanische ,zeitung and ,annales des   
,sciences ,naturelles1 #d;e srie1    t4 
xiii4 p4 #bd1 #ahfj4    ,footnote #eh3  
,communication sur l',origine et le     
,dveloppement de quelques               
,champignons4 ,dantzig1 #ahfg4          
,footnote #ei3      ,,tr,,cul1 ,comptes 
rendus de l',acadmie1 t4 lxxiii4 p4     
#aded2 ,december    #bh1 #ahga4         
,footnote #fj3      ,,tr,,cul1 ,comptes 
rendus de l',acadmie1 t4 lxxv4 p4 #aafi1

 ,november #aa1    #ahgb4 ,a proof of   
,m4 ,trcul's carelessness in experiments
 of this kind    is the fact that in    
studying the fertility of an impregnated
 wort1 he    often obtains different    
productions4 ,our experiments give      
opposite    results4 ,if we sow nothing1
 we obtain nothing4 ,if we sow a plant1 
we    obtain a similar plant2 or1 should
 there be any difference1 the change    
may be traced1 beyond question1 to its  
origin in the plant sown1 and    is the 
consequence of some alteration in the   
conditions of our    experiment4        
,footnote #fa3      ,comptes rendus des 
,sances de l',acadmie des ,sciences1 t4 
lxxv4 p4    #abbj2 ,nov4 #ah1 #ahgb4    
,footnote #fb3      ,since writing the  
above we have experienced some doubt as 
to whether    the forms of development  
represented in ,fig4 #bj are actually   
those of    the aspergillus glaucus1    
which we supposed our fungoid growth to 
be4    ,in some of the later sketches of
 our observations we find similar       

forms1 which belong to a bluish kind of 
penicillium1 with rather    large       
spores4 ,fortunately1 this doubt affects
 our argument in no    essential        
particular4 ,it matters very little what
 variety of fungoid    growth it is that
 gives rise to alcoholic fermentation   
attended by    peculiarities of shape   
that only occur in the development of   
its    spores when air fails it4        
,footnote #fc3      ,by the term conidia
 is meant certain chains of cells1 which
 are in    reality mycelial spores4     
,footnote #fd3      ,see ,,pasteur1     
tudes sur le ,vin1 #ast ,edition1 pp4   
#bj and following4    ,footnote #fe3    
,since writing this paragraph1 we have  
found in ,m4 ,ch4 ,robin's ,journal     
d',anatomie et de ,physiologie1 an      
article signed by that gentleman1    and
 entitled ,sur la ,nature des           
,fermentations1 c4 7,july-,august1      
#ahge71 in which the learned            
microscopist says3--8,the torula        
cerevisi    is derived from the         

mycoderma cerevisi4 ,my observations    
leave no    doubt on my mind that       
penicillium glaucum is one of the forms 
evolved from spores or ferments that    
have preceded it1 as ,m4 ,trcul         
showed a long time ago1 and that1       
moreover1 the spores of    penicillium1 
germinating in suitable media1 give us  
the sporical    form termed mycoderma40 
,we take the liberty to observe that    
these assertions of ,m4 ,robin's are    
purely gratuitous4 ,up to the present   
time it has been impossible to          
discover a suitable medium for the proof
 of these different    transformations  
or polymorphisms4 ,from the time of     
,turpin1 who firmly    believed that he 
had observed these changes1 to our own1 
none of the    microscopists who have   
affirmed these transformations have     
succeeded    in adducing any convincing 
proof of them1 and ,m4 ,trcul's latest  
observations1 especially as regards     
penicillium and its    transformation   
into ferment or into the mycoderma of   

beer1 have been    positively disproved 
by ours1 supported1 as they are1 by     
proofs that    we consider irrefutable4 
,footnote #ff3      ,it is a very easy  
matter to study the liquids and growths 
in our    flasks during the course of a 
single experiment4 ,we take out the     
glass    stopper that closes the        
india-rubber tube on the straight-neck1 
and1    by means of a long rod or a     
glass tube previously passed through the
    flame1 take up a quantity1 which we 
draw out immediately for                
microscopical examination4 ,we then     
replace the glass stopper1 taking       
care to pass it through the flame before
 doing so1 to burn up any    organic    
particles of dust that it may have      
picked up from the table on    which we 
laid it4    ,footnote #fg3      ,we may 
prove the occurrence of alcoholic       
fermentation by the cells of            
submerged mycoderma vini in a different 
manner4 ,to do this1 after    having    
made all our preparations as before and 

shaken up the film of    mycoderma vini 
in its liquid1 we must attach our flask 
to a test    flask 7,fig4 #ai71 and pass
 the turbid liquid into the latter4 ,on 
succeeding days we shall detect a very  
protracted fermentation in the    test  
flask2 there will be a succession of    
minute bubbles rising from    the       
bottom1 but in small number at a time4  
,the fermentation is very    evident    
whilst it lasts1 but is rather sluggish1
 and1 although of very    long duration1
 ceases long before the sugar is        
exhausted4      ,this experiment proves 
better than any other the               
non-transformation of    mycoderma vini 
into other ordinary fungoid growths4    
,for after    decanting the liquid into 
the test flasks1 the sides of the       
experimental flask remain covered with  
streaks of mycoderma vini    along with 
some of the liquid4 ,moreover1 the flask
 is refilled with    air1 and this air  
is being constantly renewed1 in part1 by
 variations    of the temperature of the

 oven1 so that the mycoderma remaining  
on    the sides is thus placed under the
 most favourable conditions for         
transformation into other fungoid       
growths1 if that were possible4 ,it     
is still more easy to detach the        
experimental from the test flask1 and   
to pass pure air into it1 once or twice 
a day1 or constantly4 ,in any    case1  
we shall never see anything besides the 
mycoderma vini spring    up within it4  
,footnote #fh3      ,see ,,pasteur1     
,comptes rendus des ,sances de          
l',acadmie des ,sciences1    t4 liv41   
#ahfb1 and t4 lv41 #ahfb4 tudes sur les 
,mycodermes1 c4    ,footnote #fi3       
,in a subsequent chapter we shall prove 
that yeast is likewise    incapable of  
transformation into mycoderma vini4     
,footnote #gj3      ,we secured the     
purity of our mycoderma by the same     
means that we have    already described 
for the procuring of spores of          
penicillium or    other fungoid growths 
in a state of purity4    ,footnote #ga3 

,,buffon1 ,histoire de l',homme1 t4     
viii41 edition #abmo1 #aggh2 ,,turpin1  
,mmoires de l',acadmie des ,sciences1 t4
 xvii42 ,dr4 ,,pineau1 ,annales    des  
,sciences ,naturelles1 t4 iii41 #ahde2  
,,pouchet1 ,trait de la    ,gnration    
dite ,spontane1 p4 #cce1 #ahei4 ,see    
also our ,mmoire sur    les ,gnrations  
dites ,spontanes1 #ahfb1 pp4 #ajj and   
following1 in    which we give a resum  
of some of these theories4    ,footnote 
#gb3      ,the following is ,turpin's   
application of his theory to the        
formation    of the ferments of fruits  
7,mmoires de l',acadmie1 t4 xvii41      
#ahdj1    p4 #aee71 where also1 on p4   
#aga the above quotation will be        
found3--,ferments ,produced by the      
,filtered ,juice of the ,pulp of        
,different ,fruits--8,by the word pulp  
we mean the soft and juicy    cellular  
tissue of the fleshy part1 mesocarp or  
middle layer of the    pericarp of      
certain ripe fruits4 ,this cellular     
tissue1 which is very    abundant in the

 peach and all stone-fruit1 in the apple
 and pear1 in    the orange and grape1  
and similar fruits1 is the same as that 
which    forms the body of a leaf4      
,being in every case composed of a      
simple    agglomeration of contiguous   
mother-vesicles1 which are always filled
    with globulines that are more or    
less developed1 more or less            
coloured1 and individually endowed with 
a special vital centre1 it is    not    
surprising that its globulines when free
 and detached from the    compound      
organisms to which they belong1 and from
 association with its    vegetable life1
 should1 when placed in a suitable      
medium1 themselves    vegetate and      
become transformed1 under these new     
influences1 into a    mucedine1 with    
filaments and articulations4 ,such are  
the very fine1    and1 consequently1    
very transparent globulines1 which1 when
 left to    themselves in sweetened     
water1 grow and become vesicular1       
producing    other globulines in their  

interior1 then bud1 vegetate into       
mucedinous    filaments1 decompose      
sugar1 and produce all the effects that 
constitute what we term alcoholic       
fermentation40    ,footnote #gc3        
,b,,champ1 ,recherches sur la ,nature et
 l',origine des ,ferments 7,annales     
de ,chimie et de ,physique1 #d;e srie1  
t4 xxiii41 and ,comptes rendus    de    
l',acadmie des ,sciences1 ,oct4 #bc1    
#ahga74    ,footnote #gd3      ,we need 
scarcely here observe1 having done so on
 previous occasions1    that whenever we
 opened our flasks to obtain specimens1 
we made use of    a fine tube1          
previously passed through the flame of a
 spirit lamp1 and    that we also passed
 this flame over the surface of the     
india-rubber1    glass stopper1 c41 to  
consume the organic particles of dust   
which    floating about might introduce 
themselves at the moment when we opened 
the right-hand tube of the flask4       
,footnote #ge3      ,ever since the year
 #ahfa 7see p4 #ib71 this question of   

the possible    transformation of the   
ordinary fungi1 especially penicillium  
and    mucor mucedo1 into yeast has     
engaged our attention4 ,the results     
attained have been entirely negative2   
but hitherto only the    conclusions of 
our work have been published1 some      
account of which was    given at the    
meeting of the ,socit ,philomathique of 
,march #cjth1    #ahfa4 ,the following  
extract is from the ,bulletin of the    
society3--8,meeting of ,march #cjth1    
#ahfa4 ,at this meeting a paper was     
read by ,m4 ,pasteur #8,on the supposed 
changes in the form and vegetation    of
 yeast-cells1 depending on the external 
condition of their    development4' ,it 
is well-known that ,leuwenhoeck was the 
first to    describe the globules of    
yeast1 and that ,m4 ,cagnard-,latour    
discovered    their faculty of          
multiplying by budding4 ,this           
interesting vegetable    organism has   
been the subject of a host of researches
 by chemists and    botanists4 ,the     

latter1 from the days of ,turpin and    
,kutzing1 have    almost unanimously    
regarded yeast as a form of development 
of various    inferior vegetable types1 
especially penicillium4 ,the studies of 
this subject which seem to have won most
 favour during the last few    years are
 those of ,,mm4 ,wagner1 ,bail1         
,berkeley1 and ,h4 ,hoffmann4 ,the      
researches of these botanists seem to   
strengthen and confirm the    original  
observations of ,turpin and ,kutzing4   
,m4 ,pouchet has1 quite    recently1    
expressed the same ideas1 and has       
determined certain points    in         
connection with them with much precision
 of detail4 ,m4 ,pasteur has    long    
studied this important question1 which  
is so intimately connected    with the  
essential nature of yeast and with those
 phenomena of the    polymorphism of the
 inferior types of vegetable life1 to   
which most of    the remarkable works of
 ,m4 ,tulasne relate2 he has1 however1  
arrived at    results that are          

altogether negative1 and he declares    
that he was    unable to detect the     
transformation of yeast into any of the 
mucedines whatsoever1 and1 inversely1   
that he could never succeed in          
producing the smallest quantity of yeast
 from ordinary mucedines40    ,these    
same results we communicated to the     
,socit ,chimique of ,paris1    at a     
meeting held ,april #abth1 #ahfa4       
,throughout the investigation of        
which we have just indicated the        
conclusions1 we insisted on the         
necessity of cultivating the separate   
organisms in a state of purity    in all
 researches relating to these inferior  
forms of life1 if we    desire to attain
 to sure inferences about them2 and the 
method of    working1 which we          
recommended1 did not differ essentially 
from that    adopted in the present     
work4 ,since then the study of these    
growths has    been conducted with the  
utmost precautions2 and other apparatus1
    perhaps as safe as those which we   

employ and better adapted than ours     
for the study of polymorphism of        
species1 have been invented by          
botanists of great skill--,m4 de ,bary1 
in ,germany1 and ,m4 ,van ,tieghem1     
in ,france4    ,footnote #gf3      ,we  
found1 after the lapse of another year1 
in ,december1 #ahgc1 that the    ferment
 of the mucor in the test glass might   
still be easily    revived2 that it was 
able to propagate1 both in the mycelium 
and in    the cellular form1 in wort1   
and that it might produce a             
fermentation1    more or less active1   
according to the condition of aeration2 
in short1    that it was capable of     
producing all the characteristic        
phenomena    described4 ,by means of the
 method of cultivation that we employ1  
our    study1 which was continued for   
years1 was pursued without the least    
fear of any foreign fungoid growths     
being introduced into the vessels1      
although they remained constantly open1 
and the air in them was being           

perpetually renewed by the action of    
diffusion and variations of             
temperature4 ,in #ahge nothing remained 
alive in our flask1 and further         
revival became impossible4    ,footnote 
#gg3      ,we do not here take into     
account certain phenomena of oxidation  
of    which the fungoid growths are the 
seat1 and which remind us of those      
that are presented in so remarkable a   
degree by mycoderma vini and            
mycoderma aceti4    ,footnote #gh3      
,there are #aedc grains in the gramme4  
,footnote #gi3      ,for ,english       
equivalent see ,experiment #a1 p4 #ace4 
,footnote #hj3      ,the figure given   
below supplies this omission4 ,the cells
 that are    isolated or are in chains1 
b4b4b41 show this state of the old      
cells4    ,the cells a4a4a4 are younger1
 and may be more easily revived4 ,we may
    see by the dimensions of some of    
these how greatly1 in certain cases1    
the cells of mucor resemble cells of    
yeast2 nevertheless1 in the    state of 

the contents and the aspect of the      
outlines1 there are always    some      
differences sufficiently appreciable to 
strike the practised    observer4       
,illustration3 ,fig4 #bc4      ,the     
figures adjoining the cells indicate    
fractions of a millimetre4 7,a          
millimetre may be taken as #e-;in47     
,footnote #ha3      #jjjjjhi in41       
#jjjjbf in4 and ,o#jjjhi in4            
respectively4                           
,,chapter ,v4                           
,the ,alcoholic ,ferments4              
,i4--,on the ,origin of ,ferment4       
,amongst the productions that appear    
spontaneously1 or1 we should rather     
say1 without direct impregnation1 in    
organic liquids exposed to contact  with
 the air1 there is one that more        
particularly claims our study4 ,it  is  
that one which1 by reason of its active 
energy as an agent of  decomposition1   
has been distinguished and utilized from
 the earliest  times1 and is considered 
as the type of ferments in general2 we  

mean the  ferment of wine1 beer1 and    
more generally1 of all fermented        
beverages4    ,yeast is that viscous    
sort of deposit which takes place in the
 vats or  barrels of must or wort that  
is undergoing fermentation4 ,this kind  
of  ferment presents for consideration a
 physical fact of the most              
extraordinary character4 ,take a morsel 
of the substance and put it in          
sweetened water1 in must1 or in dough1  
which always contains a little  sugar2  
after a time1 the length of which       
varies1 a few minutes often  sufficing1 
we see these liquids or the dough rise1 
so to speak4 ,this  inflation of the    
mass1 which is due to a liberation of   
carbonic acid  gas1 may cause it to     
overflow the vessels containing it1 if  
their  capacity is not considerably     
greater than the volume of the matters  
fermenting4 ,it is equally remarkable   
that these phenomena are natural  and   
spontaneous2 that is to say that the    
must1 the wort1 and the dough  are able 

to rise1 as we have termed it1 when left
 to themselves1 without  the least      
addition of foreign substances4 ,the    
only difference that may  occur in these
 phenomena is a certain amount of       
retardation1 in cases  where the yeast  
does not reach the saccharine matters in
 a perfectly  natural form1 inasmuch as 
it then requires a certain time to get  
itself  together before it can begin to 
act4    ,it is necessary1 indeed1 that  
sugar should be present2 for if we      
abstracted by some means or other from  
the must or dough all the sugar         
contained in it1 without touching the   
other constituents1 the addition  of    
yeast would produce no gas4 ,everything 
would remain quiet until the  moment    
when signs of a more or less advanced   
putrefaction showed  themselves4 ,yeast 
is one of the most putrescible of       
substances1 and it  is worthy of notice 
that its alteration is also the         
consequence of the  formation of one or 
more ferments1 very different1 however1 

from that of  which we are speaking4 ,as
 for the nature of yeast1 the microscope
 has  taught us what it is4 ,that       
marvellous instrument1 although still in
 its  infancy1 enabled ,leuwenhoeck1    
towards the close of the #agth century1 
to  discover that yeast is composed of a
 mass of cells4 ,in #ahce               
,cagnard-,latour and ,schwann took up   
,leuwenhoeck's observations1 and by     
employing a more perfect microscope1    
discovered that these same cells        
vegetate and multiply by a process of   
gemmation4 ,since then the physical  and
 chemical phenomena already mentioned1  
such as the raising of the  mass1 the   
liberation of carbonic acid gas1 and the
 formation of alcohol1  have been       
announced as acts probably connected    
with the living processes  of a little  
cellular plant1 and subsequent          
researches have confirmed  these views4 
,in introducing a quantity of yeast into
 a saccharine wort1 it must be  borne in
 mind that we are sowing a multitude of 

minute living cells1  representing so   
many centres of life1 capable of        
vegetating with  extraordinary rapidity 
in a medium adapted to their nutrition4 
,this  phenomenon can occur at any      
temperature between zero and #ee ,c4    
7#aca  ,f471 although a temperature     
between #ae ,c4 and #cj ,c4 7#ei ,f4 and
 #hf  ,f47 is the most favourable to its
 occurrence4    ,as regards the rapidity
 of the budding1 the following          
observations will  give some idea of    
what it is in the case of one of the    
ferments of  natural must4 ,the         
temperature was between #ab ,c4 and #ac 
,c4 7#ee ,f474    8,on ,october #ab1    
#ahfa1 at ten o'clock in the morning1 we
 crushed some  grapes1 without filtering
 the juice that ran from them2          
afterwards1 at  different times during  
the day1 we examined the juice under the
  microscope1 until at last1 although   
not before seven o'clock in the         
evening1 we detected a couple of cells1 
as represented in ,fig4 #be1 a4         

,illustration3 ,fig4 #be4    ,from that 
time we kept these contiguous cells     
constantly in view4 ,at  #g4aj we saw   
them separate and remove to some little 
distance from each  other 7,fig4 #be1   
b74 ,between #g and #g4cj we saw1 on    
each of these cells1  a very minute bud 
originate and grow little by little4    
,these buds  developed very near the    
point of contact1 where the disjunction 
had just  taken place4 ,by #g4de the    
buds had increased greatly in size      
7,fig4 #be1  c74 ,by #h they had        
attained the size of the mother-cells4  
,by #i each  cell of each couple had put
 forth a new bud 7,fig4 #be1 d74 ,we did
 not  follow the multiplication of the  
cells any farther1 having seen that in  
the course of two hours two cellules had
 furnished eight1 including the  two    
mother-cells40#hb    ,an increase like  
this1 which would have been more rapid  
at a temperature  between #ae and #be   
7#ei and #gg ,f471 and still more so    
between #be and  #cj 7#gg and #hf ,f471 

may indeed seem surprising4 ,it is      
really1 however1  nothing to what       
sometimes occurs4 ,in choosing proper   
conditions of  temperature and medium1  
of state and nature of yeast1 it has    
sometimes  happened that the bottom of a
 vessel has become covered with a white 
deposit of yeast cells1 in the course of
 not more than five or six hours  after 
we had sown a quantity of yeast so small
 as to effect no change at  all in the  
transparency of the liquid contained in 
the vessel after it  had been shaken up4
 ,such a rapidity of vegetation reminded
 us of those  exotic plants which are   
said to grow several feet in height in  
the  course of twenty-four hours4       
,illustration3 ,fig4 #bf4    ,budding   
commences in the form of a simple       
protuberance on the cell--a  kind of    
little boss1 as represented in ,fig4    
#bf1 ,no4 #a4 ,this protuberance  goes  
on increasing1 and assumes a spherical  
or oval form4 ,at the same  time1 there 
is a tendency in the points of          

attachment in the young cell  to meet--a
 kind of strangulation occurs 7,fig4    
#bf1 ,no4 #b74 ,the junction  takes     
place a little sooner or later1         
according to the species 7,fig4 #bf1    
,no4 #c72 the two individuals then      
separate 7,fig4 #bf1 ,no4 #d74 ,in      
certain  cases a single cell may give   
rise to several protuberances1 and1     
consequently1 to several daughter-cells4
 ,where there is only one  protuberance 
or bud we generally see it originate at 
the thick end and a  little on one side 
of the apex of the oval outline1 which1 
in a greater  or less degree1           
characterizes the cells of the majority 
of ferments4    ,certain authors have   
maintained that the method of budding   
which we have  just described1 and which
 we think was first promulgated by      
,mitscherlich1 is merely an illusion1   
and that the cells of yeast break  up   
and scatter their granular contents1 and
 that these scattered  granules         
eventually attach themselves to the     

cells1 growing there1 and  so giving the
 appearance of buds or daughter-cells4  
,this error has been  revived quite     
recently4#hc ,nothing can be less       
admissible4 ,we could  count the number 
of yeast cells which we have seen       
undergo this process  of rupture in the 
course of some ten years of observation1
 every day of  which1 we may say1       
thousands of these cells have passed    
under our eyes4  ,this breaking up of   
the cells is really of the most rare    
occurrence1 and  may always be explained
 by some abnormal circumstance affecting
 the  yeast2 being indeed a mechanical  
accident1 not a physiological fact4 ,we 
may easily convince ourselves of this by
 growing some yeast in a  saccharine    
wort1 filtered perfectly clear1 and1    
consequently1 deprived  of all granular 
amorphous deposit that might deceive the
 observer4 ,the  cells will be observed 
to bud and multiply without exhibiting  
the most  minute appearance of          
granulation1 or disruption2 moreover1   

there will  always be cells of all      
sizes1 ranging from the smallest visible
 up to  the largest4 ,this very simple  
piece of observation may be made in all 
the alcoholic ferments1 and with any    
wort capable of fermenting1 and in  its 
presence the hypothesis1 which we have  
been repudiating1 cannot hold  its own4 
,in ,plate ,,vii4 7left side7 there is  
represented a field of yeast1  magnified
 #djj times4 ,we see a mass of          
disjointed cells1 such as appear  after 
fermentations without sufficient        
aliment2 of the kind represented  some  
are nearly spherical1 others oval or    
cylindrical1 more or less  elongated4   
,if we mix a little of this yeast1 of   
about the size of a  pin's head1 with   
wort1 and put the wort into a small1    
shallow1  flat-bottomed basin1 having a 
surface of about #a square decimetre    
7#aj  sq4 ins47 exposing it to the      
surrounding temperature1 we shall find  
next  day the bottom of the basin       
covered with a fine white deposit1 of   

the  forms of which we give a sketch in 
the right half of the plate4 ,in this   
it will at once be observed that the    
cells sown have lost their interior     
granulations1 having become more        
transparent and filled with a           
gelatinous protoplasm4 ,the principal   
difference between the two halves  of   
the plate consists in this1 that whereas
 the cells in the left half  are        
isolated and granular1 those in the     
right half are more inflated1  more     
transparent1 and provided with buds1    
which may be seen in every  stage of    
development1 from their first appearance
 till they become as  large as the      
parent cells4 ,they continue to grow    
until they detach  themselves2 then they
 bud in their turn1 so that the same    
figure may  furnish examples of cells of
 the first1 second1 and third           
generations4  ,in the right half1 the   
protoplasm contained in the cells       
exhibits  circular spots or vacuoles1   
which may be made to appear lighter or  

darker than the rest of the cell by     
slight movements of the object-glass  of
 the microscope4 ,these spots are due to
 a migration of the protoplasm  towards 
the sides2 they commonly occur in yeast 
cells the vitality of  which1 from      
deficient nourishment1 has become       
suppressed--the shrivelled  appearance  
which they then assume being due to     
their being forced to  live upon        
themselves1 so to speak4 ,however1 by   
introducing such cells  into a nutritive
 and aerated liquid the vacuoles quickly
 disappear4    ,illustration3 ,plate #g4
 ,yeast-cells--,worn out and            
,dissociated 7left71  after ,revival in 
a ,sweet ,wort 7right74    ,in the      
ordinary yeast1 as met with in          
breweries1 the majority of cells  show  
one or more of these vacuoles2 if1      
however1 we place a little of  this     
yeast in an aerated wort1 and watch     
under the microscope the  changes that  
occur in the cells1 we shall witness1   
often in the course  of a few seconds1 a

 kind of turgescence1 a greater tension 
of the  cell-walls1 which seem to grow  
thinner1 and a complete disappearance of
  the vacuoles4 ,at the same time the   
interior gelatinous matter will  become 
filled with fine granulations that are  
scarcely visible1 but  which at a       
certain distance appear brilliant4 ,at  
the same time  protuberances begin to   
show themselves1 and next day the       
budding will  have already become very  
active4 ,the newly-formed cells will    
have such a  delicacy of aspect and     
contour as to be scarcely discernible in
 the  field of the microscope4 ,there   
will also be a tendency to ramification 
in the budding1 which appearance will be
 more or less marked according  to the  
kind of alcoholic ferments present1 as  
we shall see presently1  attaining its  
maximum in each case when the cells have
 been revived  after exhaustion by rest 
and want of food4 ,in the latter case1  
the  process of rejuvenescence may be   
protracted2 but this is not the case    

with cells of commercial yeast1 which is
 always used within a few days  of its  
formation4 ,and thus1 as ,i said a      
little ago1 speaking of these  cells1   
they often manifest the first signs of  
their budding in a few  seconds4    ,in 
our preceding remarks we have expressly 
assumed that there are many  kinds of   
alcoholic ferment4 ,this is1 beyond     
doubt1 the case1 as we have  given      
incontestable proofs1 first in #ahfb1 in
 the ,bulletin de la  ,socit chimique of
 ,paris1 and later on1 in #ahfd and     
#ahff1 in a ,note in  the ,comptes      
rendus1 on the diseases of wines1 as    
well as in our  8,studies on ,wine40    
,moreover1 we know that brewers have    
long recognized  two distinct methods of
 fermentation--8high0 fermentation and  
8low0  fermentation--and two            
corresponding yeasts4 ,it is true that  
the  differences presented by these     
fermentations were believed to be caused
  by the different conditions under     
which they took place1 and that it was  

supposed that we might change 8high0    
yeast into 8low0 yeast1 or  inversely1  
by subjecting the first to a low        
temperature1 or the second  to a high   
one4 ,in our observations of #ahfb1     
which we have just  mentioned1 we       
discovered that must gives rise to      
several yeasts2 that  the ferment of    
8high0 beer cannot develop except with  
great difficulty  in must1 whilst one of
 the ferments of the grape grows rapidly
 and  luxuriantly in wort2 that it is   
easy to isolate the smallest of the     
ferments of the grape from its          
congeners1 by subjecting filtered must  
to  fermentation2 and finally1 that the 
secondary fermentations of wines  which 
remain sweet furnish a remarkable       
ferment1 very different in  aspect to   
the ferment of beer4    ,we have not    
given specific names to these different 
ferments1 any more  than we have to the 
other microscopic organisms which we    
have had  occasion to study4 ,this was  
not from any disregard for names1 but   

from a  constant fear that1 since the   
physiological functions of these minute 
forms was the exclusive object of our   
study1 we might be led to attach  too   
much importance to exterior characters4 
,we have often found that  forms1 having
 nothing apparently in common1 belong to
 one and the same  species1 whilst      
similarity of form may associate species
 far apart4 ,we  shall give some fresh  
examples of this fact in the present    
paragraph4 ,a  ,german naturalist1 ,dr4 
,rees1 who has discovered new proofs of 
the  diversity of alcoholic ferments1   
putting aside1 perhaps rightly1 such    
scruples1 has attached specific names to
 the different kinds of  ferments1 in   
his brochure published in #ahgj1 which  
we have already  cited 7p4 #ga74        
,indeed1 we have often ourselves1 for   
brevity's sake1 made  use of the names  
proposed by ,dr4 ,rees4#hd              
,illustration3 ,fig4 #bg4    ,in a ,note
 inserted in the ,bulletin de la ,socit 
chimique de ,paris1 in  #ahfb1 we       

figured a ferment of small dimensions1  
which develops  spontaneously in must1  
filtered or unfiltered1 and which is    
very  different from the ordinary       
ferment of wine4 ,it is the first to    
make its  appearance in the fermentation
 of the grape1 and may even appear alone
  if the must has been previously well  
filtered1 doubtless because its  germs1 
being smaller than those of other       
ferments1 pass through the  filter more 
easily and in greater number4 ,fig4 #bg1
 extracted from our  ,note of #ahfb1    
represents this ferment1 together with  
some spherical  cells of high yeast1    
with the object of giving a more exact  
idea of  the relative dimensions of     
these two ferments and their            
dissimilarities4  ,dr4 ,rees has named  
it saccharomyces apiculatus4    ,the    
same savant has given the name of       
saccharomyces pastorianus to the  yeast 
of the secondary fermentations of sweet 
liquids1 such as wine that  has remained
 sweet after its principal fermentation4

 ,we have described  this yeast in a    
,note published in #ahfd1 on the        
diseases of wine1 from  which we give   
the following extract3--#he             
,illustration3 ,fig4 #bh4    8,fig4 #f  
7,fig4 #bh in this work7 represents a   
very interesting variety of  alcoholic  
ferment4 ,it happens pretty often1      
especially in the ,jura1  where the     
vintage takes place about ,october      
#aeth1 when the season is  already cold 
and little favourable to fermentation1  
that the wine is  still sweet at the    
moment when it is put into casks4 ,this 
is especially  the case in good years1  
when the sugar is abundant and the      
proportion of  alcohol high1 a          
circumstance which prevents the         
completion of  fermentation when        
effected at a low temperature4 ,the wine
 remains sweet  in cask sometimes for   
several years1 undergoing a continuous  
but feeble  alcoholic fermentation4 ,in 
such wines we have always observed the  
presence of this peculiar ferment4 ,in  

form it consists of a principal  stem1  
forming nodes at various points1 from   
which short branches arise1  ending in  
spherical or ovoid cells4 ,these cells  
readily detach  themselves1 and act as  
spores of the plant4 ,it is rarely1     
however1 that  we see so perfect a      
vegetation as we have represented1      
because the  different parts fall to    
pieces1 as we have shown in the left    
half of the  figure40    ,what is the   
origin of cellular plants of this       
remarkable type8 ,where and  how are the
 ferments of the grape generated8    ,in
 ,chapter ,,iii4  #c we were on our way 
to a solution of this question4  ,it has
 been shown that fermentation cannot    
take place in the juice of  crushed     
grapes if the must has not come into    
contact and been mixed with  particles  
of dust on the surface of the grapes1 or
 of the woody part of  the bunch4 ,it   
would1 however1 be sufficient that a    
vintage vat1 of any  capacity           
whatsoever1 should receive the particles

 of dust existing on a  single bunch in 
some cases1 on even a single grape1 for 
the whole mass  to enter into           
fermentation4    ,illustration3 ,plate  
#h4 ,fertile ,mould-cells from the      
,outer ,surface of  ,grapes4    ,what1  
then1 we must ask ourselves1 is the     
nature of these particles of  dust8 ,on 
,september #bgth1 #ahgb1 we picked from 
a vine1 in the  neighbourhood of        
,arbois1 a bunch of grapes1 of the      
variety called le  noirin4 ,the bunch   
selected1 without any injury to a single
 grape1 was  brought to our laboratory  
in a sheet of paper that had been       
previously  scorched in the flame of a  
spirit lamp1 and the grapes were cut off
 with  a pair of fine scissors1 which   
had also been passed through the flame4 
,by means of a badger-hair brush1       
thoroughly purified in water1 each      
grape to which a portion of its peduncle
 remained attached1 was washed  in a    
little pure water4 ,the successive      
washing of a dozen grapes in #c  c4c4 of

 water was sufficient to make the water 
turbid2 we then examined  it under the  
microscope4 ,each field contained many  
little organized  bodies1 accidentally  
associated1 now and again1 with some    
very scarce  crystalline spicules4 ,as a
 rule1 the organisms consisted of       
simple1  transparent1 colourless cells2 
some1 indeed1 of larger size had a      
yellowish brown colour1 and were        
detached or united in irregular masses2 
and1 lastly1 there were club-shaped or  
bottle-shaped vessels1 full of  spores  
ready to germinate4 ,we repeated this   
experiment with bunches of  other       
varieties of grape1 and also submitted  
to examination water in  which the outer
 surfaces of gooseberries1 plums1 and   
pears had been  washed2 the result was  
in each case the same1 that is1 we found
 a great  number of the same colourless 
cells1 and the same irregular masses of 
darker cells1 which latter1 however1 we 
must not confound with the  masses of   
dead cells sometimes found covering     

parts of the epidermis of  certain      
fruits4    ,as we had purposely left    
each fruit attached to part of its      
peduncle1 we  wished to ascertain if    
these corpuscles proceeded from the     
grapes or  from the wood of the         
peduncle4 ,for this purpose we washed   
separately the  surface of the grapes   
and the woody part of the bunch4 ,the   
water in  which the latter was washed   
was visibly more charged with the minute
  organisms than that in which the      
grapes was washed1 although the latter  
was by no means free from them4         
,plate ,,viii4 represents these         
corpuscles as they exist on the surface 
of  fruits1 magnified #ejj times4 ,the  
groups1 b1 b1 b1 4441 c1 c1  444 are of 
a brown colour1 more or less dark1 or of
 a reddish yellow2  the cells a1 a1 444 
are transparent4 ,amongst them are some 
spores of  ordinary fungoid growths1 and
 several cells which are probably the   
issue  of a germination that had        
commenced in certain groups which have a

 hard1  yellowish appearance1 and which 
are provided with what seems to be a    
double case--b1 b1 b1 4441 c1 c1 4441 a 
result of the moisture  of the woody    
part of the bunch1 or of rain that fell 
just before the  commencement of our    
observations4    ,it is an easy matter  
to trace the germination of these       
different  varieties of cells with the  
microscope4 ,we put a drop of the water 
in  which the woody part of a bunch of  
grapes has been washed into a small     
quantity of wort1 previously boiled and 
filtered bright4 ,plate ,,ix4  presents 
a series of developments observed in the
 case of simple or  grouped cells1 ,a1  
,d1 ,g1 and ,j4 ,the process is as      
follows3 ,the  yellowish-brown cells    
soften and grow larger in the nutritive 
medium1  and gradually become almost    
transparent and colourless4 ,at the same
 time  we see some very young buds      
appear on their margins2 these rapidly  
increase in size1 and detaching         
themselves to make room for others1 move

  off as young cells that after a time  
bud in their turn4 ,the rapidity  with  
which these cells bud and multiply is   
often extraordinary4 ,the  group ,a and 
the cell ,d produced the groups ,c and  
,f within twenty-four  hours1 passing   
through the intermediate stages         
represented in groups ,b1  ,e4 ,the     
cells ,a and ,d did not give rise to any
 filamentous growths1 at  least whilst  
under our observation4 ,some groups of  
cells1 however1 put  forth1 from the    
first1 long filaments1 having           
cross-partitions and  resembling the    
mycelium in ordinary fungoid growths4   
,together with  these1 and along their  
whole length1 was an abundance of cells1
 often in  clusters1 as represented by  
,fig4 ,g1 the whole of which growth took
 place  in less than twenty-four        
hours4#hf ,but apart from contact with  
the air1  there was a complete absence  
of life4    ,illustration3 ,plate #i4   
,various ,examples of the ,mode of      
,growth of  ,mould-cells from the ,outer

 ,surface of ,grapes4    ,the figures   
,h1 ,i1 ,j1 ,k1 represent other aspects 
of developing cells and  filaments4 ,the
 cells ,h are spherical2 the cells ,i   
have numerous buds1 as  also have those 
marked ,k4 ,these different forms were  
all produced in the  course of          
twenty-four hours by the cell which may 
be observed in the  centre of the group 
,j4 ,in connection with this same group1
 ,j1 we may  remark that on ,september  
#cj1 #ahgb1 at #aj ,a4,m41 we witnessed 
the  detachment of three oval cells at  
the points a1 b1 c2 by #aj4de  other    
buds of the size represented in our     
engraving had formed in their  place2 by
 about five o'clock that same afternoon 
these buds1 a1 b1  c1 having become     
transformed into cells1 fell off in     
their turn4#hg    ,it may be asked1 what
 proof have we that amongst the         
filamentous and  cellular growths which 
spring from the small1 dark bodies      
existing in  the particles of dust      
adhering to the surface of fruits1 and  

which we  here see bud and multiply with
 such marvellous rapidity1 the ferment  
or  ferments of vintage do actually     
exist8 ,a very simple experiment will   
prove conclusively that this is the     
case4 ,when in the course of            
twenty-four or forty-eight hours1 by    
contact with saccharine must1 and  in   
presence of excess of air1 the revival  
and development of the cells  has taken 
place on the bottom of the little       
troughs employed in our  observations2  
if then we fill up the trough with the  
same must1 so that  there remains no    
free air under the cover-glass1 within a
 very short  time--an hour1             
half-an-hour1 or often less--we shall   
see bubbles of gas  rise from the       
bottom1 accompanied by an increase in   
the deposit of  cells4 ,this will be the
 must fermenting after the submersion of
 the  cellular plants4 ,it follows that 
the cells1 or groups of cells1 of a     
dark colour which cover the grapes1 or  
the woody part of the clusters1  are    

actual germs of the cells of yeast2 more
 correctly speaking1 that  germs of     
yeast-cells exist amongst these groups1 
for it would not be  consistent with    
truth to say that the various           
germinating forms present  in the dust  
on the surface of grapes must all of    
them give rise to  actual corresponding 
ferments4 ,thus the flask-shaped spores 
c1 c1  444 in ,plate ,,viii41 are       
reproductive organs of alternaria       
tenuis1  which have probably nothing in 
common with alcoholic ferment or        
ferments1 properly so called1 except    
their outward form4 ,we may repeat1     
however1 and it is a point of great     
importance to bear in mind1 that the    
cells of yeast originate from some or   
other of the little1 brownish1          
organized bodies1 which the microscope  
reveals in such numbers amongst  the    
particles of dust existing on the       
surface of fruits4    ,the              
impossibility1 which we have already    
demonstrated 7,chapter ,,iii4   #c71 of 

making grape juice ferment apart from   
the action of external  particles of    
dust1 and the knowledge which we have   
just acquired1 that  the particles of   
dust on the surface of the grapes and   
woody peduncles1  at the moment when the
 grapes have attained maturity1 contain 
certain  reproductive cells which give  
rise to certain ferments1 naturally lead
  us to the investigation of another    
point1 which concerns the period at     
which these germs make their appearance 
on the different parts of the  vine     
plant4 ,the two following experiments   
tend to prove that the ferment  can only
 appear about the time when the grapes  
attain maturity1 and that  it disappears
 during the winter1 not to reappear     
before the end of the  following summer4
    ,i4 ,in the month of ,october1      
#ahgc1 we procured from a vineyard in   
the  canton of ,arbois some of the woody
 parts of very ripe clusters of  grapes1
 taking the precaution to cut off all   
the grapes1 one by one1  with a very    

clean pair of scissors1 whilst still on 
the vine2 we then  wrapped up the woody 
parts of the clusters1 thus deprived of 
their  grapes1 in thin paper1 to convey 
them to ,paris4 ,our only object at that
  time was to secure for use in our     
subsequent studies the ferment-bearing  
dust found in ,october on the woody part
 of the vine1 and1 more  particularly1  
on the clusters themselves1 as already  
stated4 ,after our  return to ,paris1   
and during the course of our experiments
 in ,october and  ,november1 it sufficed
 to wash a few scraps of the bunches in 
a little  pure water1 in order to obtain
 the grape-ferment in abundance2 but    
later  on in the winter we were         
astonished to find that the same        
procedure  yielded no ferment1 only some
 moulds4 ,the bunches which1 when put   
into  boiled and filtered must1 in      
,october1 very readily caused that must 
to  ferment1 at the end of winter could 
no longer produce the same effect1      
however favourable might be the         

temperature to which we raised the must4
  ,the particles of dust on the bunches 
had1 therefore1 become sterile1 as      
sources of alcoholic ferments4    ,,ii4 
,on ,february #agth1 #ahge1 we purchased
 of ,chevet1 a dealer in  provisions1   
two bunches of white grapes1 which were 
perfectly sound1  presenting not the    
slightest trace of injury or bruise4 ,we
 took an iron  pot full of mercury1     
which had been heated to #bjj ,c4 7#cib 
,f471 and  then covered over its surface
 with a sheet of paper that had also    
been  subjected to flame4 ,when the     
mercury had cooled down we placed       
several  of ,chevet's grapes1 singly and
 in small bunches1 on the surface of the
  metal1 and1 after having enclosed them
 in a glass cylinder that had been      
previously heated with and by means of  
the mercury1 we crushed them in  this   
vessel1 in contact with air1 by means of
 a strong1 crooked iron  wire that had  
been passed through the flame of a      
spirit lamp4 ,the object  of all these  

precautions was to prevent any cause of 
error1 such as  might have resulted from
 the accession of particles of dust     
associated  with the mercury1 or        
floating about our laboratory4 ,we then 
placed our  cylindrical jar in an oven1 
at a temperature of #be ,c4 7#gg ,f472  
but  though the experiment was continued
 for several days following1 no         
fermentation manifested itself4 ,at     
last1 to assure ourselves that the  pulp
 and liquid were1 notwithstanding this1 
well adapted to  fermentation1 we       
introduced into the test-flask an almost
 imperceptible  quantity of yeast4 ,this
 readily developed1 and promptly        
produced  fermentation4#ia    ,it seems 
possible1 therefore1 that the germs of  
ferment may not exist on  bunches of    
sound grapes during winter1 and that the
 well-known  experiment of ,gay-,lussac 
on the influence of air on the          
fermentation of  the must of crushed    
grapes cannot succeed at all times4     
,the following observations will afford 

more than sufficient proof of  this     
statement1 being1 after all1 but an easy
 method of carrying out  ,gay-,lussac's 
experiment1 without having recourse to  
the use of mercury4    ,it may already  
be inferred from the preceding facts    
that there must be1  in the course of   
the year1 between the end of winter and 
autumn1 a  period when the vegetation of
 the cellules from which yeast proceeds 
undergoes a revival4 ,when does this    
period occur8 ,in other words1 how  long
 after winter does sterility of the     
plant continue1 until it is  again      
capable of yielding ferment8 ,to        
ascertain this1 we conducted  numerous  
experiments during the summer and autumn
 of #ahge and the winter  of #ahgf4     
,having to conduct them in a            
vine-growing country--in the  vineyards 
of ,arbois1 ,franche-,comt--at a        
distance from our laboratory1 we  were  
compelled to adopt a simple form of     
apparatus for our experiments1  which1  
besides being very convenient1 was at   

the same time sufficiently  exact for   
the object we had in view4              
,illustration3 ,fig4 #cb4    ,into      
common test-tubes we poured some        
preserved must2 we then boiled it1  with
 the object of destroying all the germs 
that it might contain1 and  then1 having
 passed the flame of a spirit lamp over 
the upper sides of  the tubes1 we closed
 them with corks which had been held in 
the flame  until they began to carbonize
 7,fig4 #cb74 ,having provided ourselves
 with  a series of tubes prepared in    
this manner1 we carried them to a vine1 
and there dropped into some of them     
grapes1 into others bunches1 from  which
 we had taken all the grapes1 by cutting
 their peduncles2 into  others1         
fragments of leaves or the wood of the  
branches4 ,the corks were  again passed 
through the flame and replaced          
successively in each tube4  ,some of the
 grapes we dropped in whole1 some we    
crushed at the bottom of  the tubes with
 an iron rod that had previously been   

passed through the  flame2 others1      
again1 at the same moment that we       
introduced them into  the tubes1 were   
cut open with scissors1 likewise passed 
previously  through the flame1 so that a
 portion of their interior juice might  
mix  with the must in the tube4    ,our 
experiments gave the following          
results3--,as long as the grapes were   
green1 about the end of ,july and during
 the first fortnight of ,august1  we    
obtained no fermentation in our must4   
,between the #bjth and #beth of  ,august
 a few tubes underwent fermentation1 by 
the action of the little  apiculated    
ferment2 and in the course of ,september
 the number of tubes  that fermented    
increased progressively4 ,in each series
 of tubes1  however1 we always found a  
few in which there was a complete       
absence of  fermentation4    ,here are a
 few actual examples4 ,in the beginning 
of ,september we placed  grapes in      
thirteen tubes1 into some whole1 into   
others crushed ones1  taken from bunches

 of the variety known as the ploussard1 
the fruit  being already sufficiently   
ripe to be very pleasant to the taste4  
,all  the tubes of this series failing  
to give us any trace of fermentation1   
or anything besides ordinary            
moulds--which indeed appeared in all our
  experiments1 whether there was or was 
not fermentation--we began a new  series
 of experiments1 under similar          
conditions1 on ,september #bhth1 as     
follows3--    ,nos4 #a1 #b1 #c and #d   
tubes containing one uncrushed grape4   
,no4 #e tube containing two uncrushed   
grapes4    ,no4 #f tube containing two  
crushed grapes4    ,no4 #g tube         
containing two crushed grapes1 in #b    
c4c4 of water previously  boiled4       
,no4 #h tube with a fragment of a bunch 
from which grapes had been cut1  and    
occupying the entire depth of liquid4   
,no4 #i tube with a fragment of wood    
from a branch4    ,nos4 #aj1 #aa1 and   
#ab tubes with a fragment of leaf4      
,on ,september #bith and #cjth there was

 no appearance of fermentation in  any  
of the flasks1 but all contained flakes 
of fungoid mycelium4 ,on the  #ast of   
,october fermentation more or less      
marked and active occurred in  #b1 #c1  
#d1 and #e1 in which uncrushed grapes   
were1 accompanied by a general          
turbidity of the liquid1 and a          
suspension of the development of the    
fungoid growths4 ,it was still absent in
 #a1 #f1 and #g1 of which the first     
contained an entire1 the latter crushed 
grapes4 ,no4 #h1 containing the  woody  
part of the bunch1 was in active        
fermentation4 ,nos4 #i1 #aj1 #aa1 and   
#ab1 with fragments of branch or leaves1
 showed no signs of fermentation4  ,the 
following day ,no4 #a was fermenting2   
but from ,october #eth onwards  there   
was no alteration in the number of      
fermenting tubes4    ,in this series we 
determined the presence of the small    
apiculated form  of yeast 7,s4          
apiculatus7 in the tubes that fermented1
 only once  finding it associated with  

saccharomyces pastorianus4    ,we need  
hardly say that the grapes which we     
employed were perfectly  ripe1 the      
vintage having already commenced in some
 of the ,jura cantons4    ,this         
experiment shows that1 even when the    
grapes are perfectly matured1  it by no 
means follows that each individual grape
 must carry germs of  ferment1 and that 
some grapes may be crushed1 in some     
instances several  together may be      
crushed1 without being able to set up a 
fermentation4 ,in  the presence of these
 novel facts1 those who support the     
hypothesis of  the transformation of the
 albuminous matter contained in the     
juice of  grapes into yeast will no     
doubt admit the untenability of their   
opinions1 since their hypothesis        
requires that every grape or number of  
grapes1 when crushed1 should ferment1 in
 contact with air4    ,on the same day  
we prepared another series of tubes1    
using grapes of a  variety called the   
trousseau4    ,nos4 #a1 #b1 #c1 and #d  

tubes containing one whole grape4       
,nos4 #e and #f tubes containing some of
 the wood of a branch4    ,no4 #g tube  
containing some of the wood of a branch 
from which the grapes  had been         
detached4    ,in the course of the      
following days fermentation took place  
in #d1 #e1 and  #g4    ,in this case    
three out of four of the uncrushed      
grapes did not cause the  must in which 
they were placed to ferment2 whilst the 
same must  fermented in one of the two  
tubes containing wood of the branch1 and
 in  the other remained unchanged2 and1 
lastly1 the tube containing the woody   
peduncles of the bunch fermented4    ,we
 have already remarked that it was more 
particularly the wood of the  bunch that
 was charged with germs of ferment4 ,the
 truth of this  assertion was proved by 
the following series of experiments4    
,on ,october #bnd1 #ahge1 we charged at 
the vineyard twenty-four tubes1 all  of 
which were about a third filled with    
pure must that had been  previously     

boiled4    ,nos4 #a1 #b1 #c1 #d1 #e1 and
 #f tubes containing one crushed grape4 
,no4 #g tube containing two crushed     
grapes4    ,no4 #h tube containing one  
crushed grape4    ,nos4 #i1 #aj1 #aa1   
and #ab tubes containing some wood of a 
branch of the  vine4    ,nos4 #ac1 #ad1 
#ae1 #af1 #ag1 #ah1 #ai1 #bj1 #ba1 #bb1 
#bc1 and #bd tubes containing  a        
fragment of the wood of a bunch from    
which the grapes had all been  detached 
and removed4    ,in the course of the   
following days some of these tubes began
 to  ferment2 but in others only fungoid
 mycelia were visible4    ,on ,october  
#gth the following tubes were           
fermenting3 the second of the  first    
eight containing whole or crushed       
grapes2 not one of the four that        
contained wood of the branches2 whilst1 
on the other hand1 of the tubes         
containing wood of the bunches1 #ae1    
#ag1 #bj1 #ba1 #bb1 #bc1 and #bd were   
all  in full fermentation4 ,in short1   
fermentation1 and therefore germs of    

yeast1 were present in one single tube  
out of eight containing grapes2  in none
 of the four tubes containing wood of   
the vine branch2 but in  seven out of   
the dozen containing wood of the        
bunches4 ,there was no  subsequent      
change in the number of tubes that      
fermented4    ,the same day that we     
arranged this series of tubes we        
prepared  twenty-four other similar     
ones1 using the wood of bunches         
preserved  from the vintage of the      
preceding year4 ,not one of these       
twenty-four  tubes showed the least sign
 of fermentation1 although they         
contained  grape juice in presence of   
the wood of the bunches2 this was a     
further  confirmation of the sterility  
of the germs of ferment in the case of  
bunches of grapes preserved for a       
sufficient time4    ,the next question  
to be considered was1 what length of    
time after the  vintage do the germs on 
the surface of the woody part of bunches
 of  grapes preserve the faculty of     

producing yeast8 ,the following         
experiments were undertaken to determine
 this point4    ,we have just seen that 
on ,october #b fragments of the woody   
peduncles  introduced with must1 on the 
spot1 caused that must to ferment in    
seven  cases out of twelve4 ,in order   
that we might test the wood of these    
same  bunches during winter we took care
 to wrap some fragments up in paper     
previously passed through the flame4 ,we
 afterwards took occasion to test       
portions of these fragments as          
follows3--    ,on ,december #bast1      
#ahge1 we conducted an experiment with  
twelve4 ,on the  following days all     
began to show flakes of mycelium1 or    
numerous  multiplying cells of          
mycoderms1 torul1 and dematium2 and only
  four subsequently produced yeast and  
alcoholic fermentation4 ,from this  we  
may conclude that1 three months after   
the vintage1 a large number of  the     
germs of yeast spread over the woody    
part of the bunches lose their          

vitality1 through desiccation by the    
surrounding air1 since two-thirds  of   
the examples taken had become sterile by
 that time4    ,on ,january #bast we    
conducted a similar experiment with     
twelve other  tubes4 ,at a temperature  
between #bj and #be ,c4 7#fh to #gg ,f47
  fermentation occurred in only two of  
them4 ,on ,march #bnd we undertook      
another experiment1 again using twelve  
tubes1 and again fermentation  occurred 
in two tubes4    ,by the beginning of   
,april the sterility was absolute4 ,at  
that period of  the year 7,april and    
,may7 we made numerous experiments of   
this kind1  using the woody parts of    
fresh bunches of grapes and white grapes
  preserved from the last vintage1      
plenty of which were still to be had in 
a state of freshness at the provision   
store4 ,we also operated on some  wood  
obtained from a vineyard at ,meudon4 ,in
 a great number of cases no             
fermentation occurred2 it even happened 
that a whole bunch of fresh  black      

grapes1 very ripe1 which were bought at 
,chevet's on ,april #afth1  and which   
had been grown in a hot-house1 after    
having been crushed1 did  not ferment at
 all4    ,up to ,march not one of the   
tubes containing the wood of dry bunches
  brought from the ,jura1 which had     
fermented1 showed any signs of          
apiculatus or of pastorianus1 or        
anything besides the ordinary low  yeast
 of wine1 saccharomyces ellipsoideus4#ic
    ,it would be a study of much        
interest to determine if yeast exists on
  other species of plants besides the   
vine4 ,during the winter we could       
discover it on no others4 ,once during  
the winter1 experimenting on box1  we   
obtained fermentation in one of our     
tubes which contained must4 ,in a  great
 number of other experiments we obtained
 nothing besides moulds and  growths of 
dematium1 alternaria1 and torulace4     
,our observations in ,chap4 ,,iii  #f1  
taken in connection with those which  we
 have just made1 prove that the yeasts  

of fermentation1 after being  dried1    
preserve the faculty of germination     
longer than the germ-cells  which are   
scattered over the dead wood of the     
vine4    ,as might be expected1 a       
microscopical examination of the        
particles of  dust scattered over the   
surface of the fruit and woody peduncles
 of  grapes1 reveals great differences  
in the number of these fertile          
particles at different periods of the   
vegetation of the grapes4 ,as long  as  
the grapes are green and the vine in    
full activity we find scarcely  any1 or1
 at all events1 very few spores which   
seem to belong to ordinary  fungoid     
growths4 ,towards autumn1 however1 when 
the grape is ripening and  the leaves   
becoming yellow1 fungoid growths and    
numerous productions of  great fertility
 accumulate on the vine1 on the leaves1 
the branches1 and  the bunches4 ,at this
 period we find the water in which the  
grapes and  the woody parts of the      
bunches are washed swarming with        

different kinds  of organized           
corpuscles2 it is at this period1 too1  
that the  ferment-yielding moulds attain
 that phase of their vegetation in      
which1  when mixed with the juice of    
grapes1 they produce fermentation4      
,in the ,jura district a peculiar kind  
of wine1 called straw wine 7vin de      
paille71 is manufactured1 which seems to
 contradict what we have said  as to the
 advent of sterility towards the end of 
winter in the  yeast-germs formed on the
 surface of preserved bunches of grapes4
 ,this  straw wine is made of grapes    
preserved for long after the vintage on 
straw4 ,from what we have said it might 
be supposed that fermentation  could not
 occur under these circumstances4 ,we   
have1 in fact1 no doubt  that it is     
often really produced by quite different
 yeast-germs from  those which cause    
fermentation in the vintage gathered in 
autumn4  ,fermentation as effected in   
the manufacture of straw wine is        
probably  due to yeast-dust spread over 

the utensils of the vine-grower1 and    
derived from the preceding vintage4 ,we 
have seen 7,chap4 ,,iii4  #f7 that      
yeast may be dried and reduced to       
powder1 and yet preserve its faculty  of
 germination for several months4 ,it    
would be useful1 however1 to  submit    
this surmise to the test of experiment1 
and it would be easy to  do so provided 
we took care to crush the grapes so     
preserved in very  clean vessels1       
previously heated to a temperature of   
#ajj ,c4 7#bab ,f471  having first      
rejected every bunch containing injured 
grapes1 which might  have fermented or  
given occasion to the development of    
yeast4  ,fermentation1 we believe1 would
 not then take place4    ,illustration3 
,plate #aj4 ,one of the ,ferments of    
,acid ,fruits at the  ,commencement of  
,fermentation in its ,natural ,medium4  
,another consequence results from the   
various facts that we have brought  out 
in relation to the origin of the        
wine-ferments1 which is1 that it  would 

be easy to cultivate one or more        
vine-stocks so that the grapes  gathered
 from them1 and crushed to extract their
 juice1 would be unable  to ferment     
spontaneously even in autumn4 ,for this 
purpose it would be  sufficient to keep 
the bunches out of contact with         
particles of dust  during the vegetation
 of the bunches and the ripening of the 
grapes1 and  then to effect the crushing
 in vessels thoroughly freed from germs 
of  alcoholic ferments4 ,moreover1 every
 fruit and every vegetable might be     
submitted to important investigations of
 this kind1 the results of  which1 in   
our opinion1 could hardly be doubtful4  
,the following observations1 which      
relate to the polymorphism of           
saccharomyces pastorianus1 seem to me to
 have an important bearing on  the      
history of alcoholic ferments1 as       
presenting a close analogy between  the 
species of ferment and fungoid growths  
of a higher order1 for  example1 such   
fungi as dematium1 which are generally  

found on dead  wood2 and we would say   
that between the vine and other shrubs  
there is  only this difference1 that    
amongst the dematium forms of the vine  
there occur one or more which are       
anarobian1 at a certain period of the   
year1 whilst1 on the other hand1 the    
dematia1 alternaria1 c41 of  other      
shrubs are more generally arobian4      
,there would be nothing  surprising in  
this result1 considering that amongst   
the mucors1 for  instance1 we find both 
arobian and anarobian forms1 and that   
there are  likewise torul-ferments or   
anarobian forms1 as well as torul-forms 
exclusively arobian4    ,when           
saccharomyces pastorianus begins to     
develop from its natural  germs1 such as
 are scattered over the surface of acid 
fruits1 it takes  the form of elongated 
jointed filaments1 branching1 often     
pear-shaped1  and more or less          
voluminous4 ,in proportion as the oxygen
 held in  solution in the liquid        
disappears and the buddings are         

repeated1 the  length and diameter of   
the filaments and cells diminish1 and   
such is the  transformation that we     
might1 at last1 suppose that we were    
dealing with  a different ferment of    
smaller dimensions4    ,plate ,x4       
represents this ferment1 at the         
commencement of fermentation in  cherry 
juice4 ,in the course of a short time   
there is nothing to be seen  but cells  
of comparatively small size1 disjointed 
and round or oval1 and  filaments       
comparatively short and slender4 ,this  
appearance is indicated  in our drawing 
by the cells a1 a1 a4 ,as these latter  
forms  multiply with great rapidity1 we 
soon have to search widely over the     
microscopic field before we find any of 
the long forms from which they  spring4 
,instead of the forms given in ,plate   
,x41 we have only those  represented in 
,plate ,,xi4 ,in other words1 the aspect
 of these ferments  changes daily1 from 
the very commencement of fermentation4  
,thus the  yeast would appear to grow   

smaller1 coincidently with the progress 
of  fermentation passing from a         
condition in which it consists of large 
cells and long ramified filaments1 to a 
condition in which the cells are  small 
and the filaments short4 ,these changes 
are principally due to an  alteration in
 the method of budding and in the       
life-processes of the  yeast1 which     
speedily exhibits itself when the air   
supply is reduced1  and not through any 
intermixture of foreign ferments4 ,so1  
at least1 all  our observations up to   
the present time lead us to believe4 ,as
 soon as  the oxygen has been absorbed  
the cells which form are oval or        
globular1  and the filaments do not     
lengthen or become so plump4            
,illustration3 ,plate #aa4 accharomyces 
,pastorianus1 in course of ,regular     
,growth4    ,this is1 however1 not the  
only cause of these changes in form and 
aspect1 although the presence of air1 in
 greater or less quantity1 has a  marked
 influence on the earlier developments  

of yeast2 there is another  circumstance
 to be taken into account1 difficult    
indeed to state  shortly1 but which is  
demonstrated clearly by the microscope1 
and is  connected with the actual state 
of the germ cells4 ,as a general rule   
the  budding of a cell is not an        
identical process when the cell is quite
  young1 and when it has become         
exhausted from want of nourishment4     
,between these two conditions there is a
 difference which may be compared  with 
that which exists1 for example1 between 
a newly-formed grain which  would not   
germinate1 and the same grain matured by
 rest1 if we may use  the expression1   
that is1 which has been kept long enough
 for its  germination to be possible4   
,in other words1 and as far as our      
subject is  concerned1 we are not to    
expect that1 by reviving our old yeast  
cells  and putting them to grow with    
abundance of air1 in a saccharine1      
nutritive medium1 we shall obtain the   
appearance of the earlier  developments 

of the germ-cells on the surface of     
sweet and acid fruits4  ,we see this    
clearly in ,plate ,,vii41 the right-hand
 half of which  represents the recruited
 budding of cells1 such as those        
represented in  the left-hand half1 in a
 medium peculiarly adapted to their     
vitality1  and in the presence of much  
air4 ,as regards the length and size of 
filaments and cells1 there is little    
appreciable difference between the  two 
sides4 ,the principal difference        
consists in the relative freshness  and 
the budding going on in individuals in  
the right-hand half4    ,there is a     
simple means of transforming the small1 
disjointed forms of  the yeast as it    
occurs in a deposit1 at the end of a    
fermentation1 back  into the long1      
tubular1 pear-shaped forms peculiar to  
the germination of  the germ-cells1     
which exist amongst the particles of    
dust spread over  the surface of fruits4
 ,plate ,x4 illustrates the result of   
the process4  ,for this purpose we must 

effect as complete an exhaustion as     
possible of  the ferment saccharomyces  
pastorianus1 by leaving it to itself for
 a  very long time1 without aliment1 in 
contact with pure air1 in a damp  state2
 or1 better still1 in presence of       
sweetened water4 ,we cultivate  some    
yeast in wort1 in one of our two-necked 
flasks1 and then carefully  decanting   
the fermented liquid through the        
right-hand neck1 leave the  deposit of  
yeast on the sides of the flask4 ,the   
glass stopper which  closes the         
india-rubber tube must be replaced1 and 
the moist yeast be  left thus1 in       
contact with pure air4 ,the cells will  
steadily continue  their activity1 and  
so gradually age1 without meanwhile     
losing their  vitality4 ,we use the word
 age1 as we have already observed1      
because  the period of rejuvenescence in
 the case of such a yeast is so much the
  slower the longer the plant has       
remained in that state4    ,under these 
conditions the yeast rarely dies4 ,it   

becomes attenuated and  shrivelled but  
still preserves its vitality1 that is1  
the power of  reproducing itself after a
 lapse of several months or even several
  years4 ,in the end1 however1 it dies1 
a fact which is proved by the  cells1   
when sown in a nutritive medium1        
remaining inert4    ,to exhaust yeast1  
without destroying it1 sweetened water  
is preferable4  ,having decanted the    
beer1 we substitute in its place water  
sweetened  with #aj per cent4 of pure   
sugar4 ,by effecting the substitution in
 the  following manner1 we escape the   
risk of introducing germs from floating 
particles of dust1 which would nullify  
all experiments of this kind4 ,we       
prepare1 then1 a flask containing       
sweetened water1 free from all foreign  
germs1 which we attach to the other     
flask i4e41 two of ,m4 ,pasteur's       
flasks with two necks1 one straight and 
wide1 the other bent and narrow  7,fig4 
#h74 ,this is done by taking the        
india-rubber tube off the flask         

containing yeast1 and removing the glass
 stopper from the other  india-rubber   
tube attached to the flask containing   
the sweetened water2  then1 introducing 
the right-hand neck of the yeast flask  
into the  india-rubber tube connected   
with the other1 we raise the latter     
flask so  as to pour the sweetened water
 on to the yeast4 ,at the same time an  
assistant passes the flame of a         
spirit-lamp over the bent part of the   
curved tube attached to the water flask1
 with the object of destroying  the     
vitality of the germs in the floating   
particles of dust1 which enter  the     
flask in proportion as it is emptied    
into the other4    ,the sweetened water1
 which is thus brought into contact with
 yeast of  greater or less freshness1   
soon begins to ferment4 ,fermentation   
accomplished1 the vinous liquid is      
decanted and replaced by fresh          
sweetened water1 which ferments in its  
turn1 although even at this stage  with 
greater difficulty than the first2 this 

second dose is again  decanted1 and     
again replaced by fresh sweetened water1
 and this process  is repeated three or 
four times4 ,the yeast becomes weaker   
and weaker1  and eventually is unable to
 cause any fermentation in sweetened    
water  poured on it4    ,this exhaustion
 of yeast in sweetened water may be     
produced more quickly  by the following 
means3--,it is sufficient to sow a mere 
trace of pure  yeast in a large quantity
 of sweetened water1 say #ajj c4c4      
7nearly four  fluid ounces71 that is1   
instead of pouring the contents of a    
bottle of  sweetened water upon the     
whole deposit of yeast in the flask     
which  contained the fermented wort1 we 
simply take a little yeast1 by means of 
a fine tube1 from the deposit at the    
bottom of the flask1 and introduce  it  
into the flask of sweetened water4 ,this
 large proportion of liquid is  itself  
sufficient to exhaust the small quantity
 of yeast1 quickly  checking the feeble 
fermentation which it had induced1 so   

feeble indeed  as frequently not to be  
detected by the eye1 from the fact that 
the  amount of liquid present is more   
than sufficient to dissolve any bubbles 
of carbonic acid gas that might         
otherwise have been liberated4    ,it is
 a remarkable fact that the yeast1 which
 during its protracted stay  in the     
sweetened water becomes enfeebled to    
such a degree that it can no  longer    
excite the least fermentation in that   
water1 but will remain in  its presence 
for an indefinite time in a state of    
inert dust1 does not  die4 ,in some of  
my experiments the yeast has remained   
alive in the  sweetened water for more  
than two years4#id ,it is almost        
unnecessary to  point out that these    
results are altogether out of keeping   
with the  various properties that are   
usually attributed to yeast4#ie    ,in  
these experiments we may use            
yeast-water#if instead of water         
sweetened with sugar4 ,into some flasks 
of pure yeast-water we put a  little    

yeast1 taking all precautions to prevent
 the introduction of  foreign germs4 ,no
 fermentation results1 there being no   
sugar present2  the yeast1 however1     
begins to bud1 and this budding is more 
or less  marked according to the        
quantity of carbohydrate food which we  
introduce  along with the specimen4 ,an 
interior chemical action also goes on1  
causing a gradual change in the aspect  
of the yeast4 ,the plasma of the  cells 
collects about the centres1 assuming a  
yellowish-brown colour1  becoming       
granular1 and forming within the cells  
masses more or less  irregular in shape1
 very rarely spherical4    ,we may      
observe here that these conditions seem 
to be peculiarly adapted  to show the   
character of the interior sporulation of
 the cells  discovered by ,dr4 ,rees4   
,notwithstanding this we have never     
succeeded in  finding it distinctly1    
under these circumstances4    ,the fact 
which should claim all our attention1 we
 repeat1 is1 that this  exhausted1      

shrivelled-up1 aged-looking yeast       
preserves its faculty of  germination   
for several years2 that1 moreover1 this 
faculty may be  aroused by placing it in
 aerated nutritive media1 in which case 
it will  exhibit all the peculiarities  
which1 under similar conditions1        
characterize some of the germ-cells     
found on the surface of our sweet       
domestic fruits4 ,in other words1 this  
yeast1 instead of multiplying1 as  it   
always does in the course of several    
growths in saccharine musts1 in  the    
form of cells which detach themselves   
readily as soon as they have  nearly    
attained the form and size of the       
mother-cells1 begins to shoot  out into 
such beautiful forms as those of        
dematium pullulans1  producing like that
 ferment long1 well-grown1 branching    
filaments1 as  well as plump and        
frequently pyriform cells1 as           
represented in ,plate ,x4    ,the       
following figures 7#cc to #cg7 and      
descriptions of the observations to     

which they relate will furnish fresh    
proofs of our assertions4 ,in these     
figures we see saccharomyces            
pastorianus1 which has been exhausted in
  sweetened water or in yeast-water1    
undergo revival in saccharine musts1    
give rise to elongated1 branching1      
pear-shaped forms1 such as belong to    
the original ferments of fruits1 and    
afterwards assume the most minute  forms
 that we find in fermentations          
progressing or completed4    ,let us    
examine ,fig4 #cc4 ,the history of this 
growth is as follows3--    ,some        
spontaneous yeast which1 after repeated 
cultivation1 had acquired  the aspect   
represented in ,plate ,,xi4--which      
aspect the saccharomyces  pastorianus   
generally assumes under these           
circumstances--was exhausted  in        
sweetened water1 and subsequently       
revived in must at #aj ,c4 to #aa ,c4   
7#ea ,f474 ,at this temperature         
germination was not very marked before  
the  end of eight days2 at a temperature

 of #bj ,c4 7#fh ,f471 it only took     
three days1 under similar conditions4   
,the sketch includes but one of the     
long branches from which the ferment    
cells and the budding joints took  rise1
 but there were a great number more4    
,some of the forms represented  in the  
figure bear a striking resemblance1 it  
appears to us1 to some of  those of     
dematium1 in ,plate ,,ix42 and even we  
may trace out the several  peculiarities
 of form which distinguish the figures  
in the latter plate4    ,illustration3  
,fig4 #cc4    ,the next figure 7#cd7    
represents the earliest forms of        
germination of  another specimen of     
saccharomyces pastorianus in wort1 after
 it had  been exhausted by four         
successive growths in sweetened water4  
,we here  see the large ferment-form    
which appears at the commencement of    
fermentation1 in acid fruits1 such as   
cherries and gooseberries 7,plate       
,,ix471 associated with smaller forms1  
which follow it and emanate from  it1 in

 proportion as the process of budding is
 repeated4 ,the field was  covered with 
this minute form1 and we had to search  
about considerably  before we could find
 any of the large cells and the long1   
branching1  jointed filaments which we  
have sketched4 ,the reason of this was1 
that  these large1 extended filaments   
only appear at the beginning1 when there
  is still an abundance of air1 giving  
place1 after repeated budding1 to       
minute cells or short filaments1 the    
ever-increasing number of which  soon   
hides the others from sight4            
,illustration3 ,fig4 #cd4               
,illustration3 ,fig4 #ce4    ,fig4 #ce  
represents saccharomyces pastorianus    
again1 as it appears  after having been 
exhausted by two years preservation in  
yeast-water1 in  contact with pure air4 
,strange to say1 it has lost its        
elongated  appearance1 and would appear 
to have originated from a round ferment4
  ,the cells are much exhausted1 and    
most of them seem to have a double      

border2 their interior is very granular 
and of a yellowish colour4 ,one  might  
readily take the specimen to be a dead  
old ferment1 which1  however1 it by no  
means is4    ,fig4 #cf represents the   
germination of this ferment1 which had  
previously  been revived in a flask of  
wort1 at the temperature of the air1 in 
,may1  #ahge4 ,the following are the    
details of our observation3--    ,we    
sowed a trace of the exhausted yeast    
7,fig4 #ce7 in a flask of wort on  ,may 
#afth4 ,the sketch 7,fig4 #cf7 was made 
on ,may #aith1 but on the #ahth  there  
was a sensible revival4 ,it will be seen
 how much the little  ferment had       
developed in the course of three days   
from the time when the  process         
commenced4 ,if we had waited a few days 
longer before taking our  sample1 we    
should probably have had difficulty in  
finding any cells or  filaments of the  
large ferment form1 as there would have 
been so few of  them in comparison with 
the others4    ,illustration3 ,fig4 #cf4

    ,in the above figure we should      
remark the chain of large cells and     
long-jointed processes1 a1 b1 c1 d 3 d  
is one of the cells  that we sowed2 it  
has become transparent1 and its         
contents1 which are  slightly granular1 
have lost their brownish tint2 c is a   
large cell  which sprang from the       
preceding one2 its outline is clear1 and
 it is  full of fine1 yellowish         
granules1 which present a perfect       
resemblance to  the large ferment-cells 
of fruits1 proceeding from the          
germ-cells on the  surface of those     
fruits1 when it begins to appear in     
sweet juices2 b  is a long filament1    
sprung from the preceding cell2 and1    
last of all1  a is a joint and its bud1 
in which the border is not yet very     
clearly  defined2 it has scarcely any   
granules1 and is finer than the others1 
belonging1 in short1 to the small       
ferment form represented in ,plate ,,xi4
  ,here1 then1 we see the transition of 
the large ferment to the small1 on  the 

same branch1 after two generations from 
the germination of the  germ-cell d4    
,this observation corroborates the      
opinion maintained by  us1 that in      
,figs4 #cc1 #cd1 #cf1 as in ,plate ,x41 
we have not a mixture of  two ferments1 
the one consisting of large1 elongated  
filaments1 the  other of small cells1   
but one and the same ferment1 the       
differences in  the form and size of    
which depend on particular conditions4  
,the smallest  ferment-form very soon   
becomes the only one visible1 and it    
preserves  its peculiar appearance in   
successive growths from inability to    
return  to the full1 elongated1         
filamentous forms before undergoing a   
prolonged  exhaustion4 ,the ferment of  
mucor would probably afford similar     
indications3 it would be very           
interesting to find out4                
,illustration3 ,fig4 #cg4 #a ,div4      
#a_/dejth of millimetre 7#a_/aabejth of 
in474    ,the following is one of the   
most curious of the forms presented by  

saccharomyces pastorianus1 occurring    
after exhaustion in a sweet  mineral    
liquid4 ,the ferment1 taken from a      
closed vat1 in which it had  been used  
for beer1 was sown in the mineral liquid
 on ,july #dth1 #ahgc4  ,the following  
days the ferment developed feebly1 but  
perceptibly1 and  gradually increased in
 bulk4 ,the flask was left to itself in 
an oven at  #be ,c4 7#gg ,f47 until     
,december #crd1 when we ascertained that
 all the  sugar had fermented4 ,we then 
sowed a trace of the deposit1 which had 
become abundant1 in a flask of pure     
wort4 ,on ,december #dth there was no   
perceptible change4 ,on ,december #eth1 
however1 fermentation was in active     
progress2 a large quantity of froth     
covered the surface of the liquid1  and 
a considerable deposit of ferment had   
already taken place at the  bottom4 ,we 
made a microscopical examination of this
 deposit1 a sketch of  which we append  
7,fig4 #cg74 ,the dark1 double-bordered 
cells are those  which were sown but did

 not rejuvenesce4 ,we may notice in     
different  places several of these same 
cells1 recognizable by their granular   
contents1 which they are beginning to   
lose1 to make room for germinating      
cells and joints1 often numerous4 ,for  
instance1 in the group at the  bottom of
 our figure one of the cells is in      
course of rejuvenescence and            
germination1 and has given rise to no   
fewer than six cells1 filaments1  or    
groups of filaments4 ,in different      
fields of our microscope we met  with a 
crowd of branches1 more or less         
ramified1 and chains of cells1 of       
greater or less length1 of which we have
 sketched a few4 ,in proportion  as the 
budding of these branches is repeated1  
the cells and joints  become more       
readily disunited1 grow small1 and      
assume the appearance of  saccharomyces 
pastorianus in ordinary growths1 almost 
as represented  in ,plate ,,xi4 ,at     
first1 when the old1 exhausted cells    
begin to germinate1  their appearance   

rather resembles that of dematium       
pullulans1 as seen  in the germination  
of many of the corpuscles on the surface
 of clusters  of grapes or fruits1 or   
their woody parts1 some specimens of    
which are  to be found in ,plate ,,ix4  
,we may briefly summarize the leading   
facts demonstrated in the above         
paragraph4 ,we have seen that there are 
different alcoholic ferments4 ,in  the  
fermentation of natural saccharine      
juices1 which1 especially when  acid1 so
 readily undergo a decided alcoholic    
fermentation1 the ferments  originate in
 certain germ-cells1 which are spread in
 the form of minute  spherical bodies of
 a yellow or brown colour1 isolated or  
in groups1  over the exterior surface of
 the epidermis of the plant1 and which  
are  gifted with an extraordinary power 
of budding with ease and rapidity in    
fermentable liquids4 ,the presence of   
atmospheric oxygen is indispensable  to 
the germination of these germ-cells1 a  
fact which explains  ,gay-,lussac's     

observation that atmospheric oxygen is  
necessary for the  commencement of      
spontaneous fermentation in must4#ig ,of
 these various  ferments one deserves   
special mention--namely1 the variety    
termed  saccharomyces pastorianus4 ,as  
is the case with all ferments1 when we  
gather it from the deposits produced in 
must that has been fermented by  its    
action1 it is composed entirely of oval 
or spherical cells or of  short joints4 
,when again placed in a similar must it 
buds1 like all the  ordinary ferments1  
and the buds detach themselves from the 
joints or  mother-cells as soon as they 
have attained the size of these latter1 
from which time in the new deposit is   
reproduced the original  ferment-form   
from which it sprung1 and so on4 ,under 
certain conditions  of exhaustion1      
however1 which may be easily obtained1  
and which we have  already accurately   
described1 the cells undergo an absolute
 change as  regards their capabilities  
of budding and germinating4 ,each cell1 

modified in its structure by the        
conditions we have mentioned1 shows a   
tendency to shoot out all around its    
surface1 with astonishing rapidity1     
into a multitude of buds1 from many of  
which spring branching chains1  covered 
in parts1 and more especially at the    
internodes1 with cells and  jointed     
filaments1 which fall off and bud in    
their turn1 soon to present  the forms  
of the yeast deposit4 ,in this way      
saccharomyces pastorianus  seems to     
afford a kind of bond of union between  
the race of ferments on  the one hand1  
and certain kinds of ordinary fungoid   
growths on the  other4 ,of these latter 
the plant which ,de ,bary has named     
dematium1 and  which is generally found 
on the surface of leaves or dead wood1  
more  especially1 however1 on the wood  
of the vine at the end of autumn1 the   
time of the vintage1 presents a striking
 example4    ,there seems every reason  
to believe that at this period of the   
year one  or more of the varieties of   

dematium furnish cells of yeast1 or even
  that the ordinary arobian varieties of
 dematium produce at a certain  stage of
 their vegetation1 in addition to       
arobian cells and torul1  other cells   
and torul which are anarobian1 that is1 
alcoholic  ferments4    ,in this manner 
we arrive at the confirmation of an idea
 entertained by  most authors who have  
studied yeast closely--namely1 that it  
must be an  organ detached from some    
more complex vegetable form4 ,we may    
also add  that in the case of           
saccharomyces the chains of filaments1  
both  tubular and fusiform1 and septate 
cells more or less pyriform  originating
 in them1 when attentively observed1    
remind us forcibly of  the filamentous  
chains and spore-balls1 or conidia of   
mucor racemosus  when submerged1 so that
 one might suppose that the             
spore-ferment of our  dematium is itself
 an organ detached from some still more 
complex  vegetable form1 in the same way
 that conidia-ferment of mucor          

racemosus belongs to that more complex  
fungoid growth4    ,in the following    
passage ,de ,bary uses1 for the first   
time1 the words  dematium pullulans     
7,hofmeister1 vol4 ii4 p4 #ahb1 #ahff74 
,the ,german  naturalist begins by      
citing the opinions of ,bail1 ,berkeley1
 and ,h4  ,hoffmann1 the first of whom  
maintains that mucor mucedo becomes     
transformed into the yeast of beer1 the 
second that yeast is a peculiar  state  
of penicillium1 and the third that it   
may be generated by fungi  of very      
different nature1 and especially by     
penicillium glaucum and  mucor mucedo4  
,he goes on to say3 8,i have taken great
 pains to repeat  the experiments of    
,bail1 ,berkeley1 and ,h4 ,hoffmann1 but
 ,i have never  been able to confirm the
 results which they have stated1 either 
in the  case of growths in microscopic  
cells or in experiments performed in    
test-tubes with the purest possible     
substances--specially prepared          
solutions or must of wine and spores of 

penicillium1 mucor mucedo1  botrytis    
cinerea1 c40 ,on this point ,m4 ,de     
,bary arrives at exactly the  same      
results which we communicated to the    
,socit ,philomathique and  the ,socit   
,chimique of ,paris1 as already given in
 ,chap4 ,,iv4  #d1 p4  #abh1 note4      
,m4 ,de ,bary goes on to say3 8,in      
researches of this kind it is difficult 
to eliminate two sources of error4 ,on  
the one hand1 it is beyond doubt  that  
cells of ferment are actually scattered 
over everything1 and that1              
consequently1 they may easily get into  
the experimental liquid along  with the 
spores that we sow1 and so occasion     
mistakes4 ,on the other  hand1 there are
 a great many fungi which develop       
budding processes  similar to yeast1 but
 incapable of producing fermentation1   
which yet in  some cases spring directly
 from spores as well as from mycelium1  
especially we may instance exoascus4    
,this last observation is  especially   
applicable to the extraordinarily       

numerous variety of fungi  which rank   
under the ,dematiei and ,sphaeriacei1   
and which ,i shall term1  for           
convenience of naming1 dematium         
pullulans40#ih    ,we shall conclude    
this paragraph with a remark that has   
doubtless  presented itself to the minds
 of our readers1 which is1 that it would
 be  impossible to carry out the        
experiments we have described if we     
could  not make sure of dealing with    
pure ferments1 or1 at least1 with       
mixtures  the components of which are   
sufficiently well known for us to assign
 to  each the effect produced by it in  
the total phenomena observed4 ,it would 
be extremely difficult to continue      
growths of yeast-deposit in sweetened   
water or in a moist atmosphere if the   
little plant were mixed with  spores of 
other fungoid growths1 a variety of     
ferment-forms1 and germs  of bacteria1  
vibrios1 or infusoria in general4 ,all  
these foreign  organisms would tend to  
develop just in proportion as the       

conditions of  the media were more or   
less favourable to their growth1 and1 in
 a very  few days1 our flasks would be  
filled with swarms of beings which1 in  
most cases1 would entirely conceal the  
facts relating to those forms1  the     
separate study of which it was our      
object to follow out4 ,we shall  have   
occasion1 therefore1 to examine1 in a   
subsequent paragraph1 the  preparation  
of ferments in a state of purity4 ,at   
present we may state  that yeast1 which 
in its ordinary condition is a mass of  
cells so liable  to change that its     
preservation in a moist state is        
impossible1  manifesting in the course  
of a few days during the winter1 and in 
twenty-four hours during the heat of    
summer1 all the signs of incipient      
putrefaction1 thereby losing its        
distinctive characteristics1 is         
nevertheless capable1 when pure1 of     
enduring the highest atmospheric        
temperatures for whole years without    
showing the least signs of putrid       

change or contamination with any other  
microscopic organisms1 and  without the 
cells losing their power of             
reproduction4 ,in the presence of  facts
 like these1 the theory of spontaneous  
generation must seem  chimerical4 ,the  
hypothesis of the possible              
transformation of yeast into            
penicillium glaucum1 bacteria1 and      
vibrios1 or conversely1 which the       
theories of ,turpin1 ,h4 ,hoffmann1     
,berkeley1 ,trcul1 ,hallier1 and ,bchamp
  involve1 is equally refuted by these  
facts4                                  
,,ii4--,on 8,spontaneous0 ,ferment4     
,the expression spontaneous ferment may 
be applied to any ferment that  appears 
in a fermentable liquid without having  
been purposely sown in  it4 ,in this    
respect the ferments mentioned in the   
preceding paragraph1  those of all      
saccharine juices of fruit which ferment
 when left to  themselves--the ferments 
of wine1 for example--are spontaneous4  
,the term1  however1 is not altogether  

appropriate1 because1 after all1 the    
process  is the same as if an actual    
sowing had been made1 since1 as we have 
shown1 it is absolutely necessary for   
the juice to come into contact  with the
 surfaces of the fruit1 so that the     
ferment may be mixed with  it1 and so   
produce subsequent fermentation4        
,therefore1 although we may  apply the  
term spontaneous ferment to the ferments
 of fruits1 we  intend that expression  
to apply in this paragraph solely to    
those  ferments that are generated in a 
saccharine liquid1 in which1 by         
previous boiling1 we have destroyed all 
ferment germs1 and which1  nevertheless1
 enters into fermentation after being   
exposed in free  contact with air4 ,in  
such a case it is entirely from the     
particles of  dust floating in the air  
that the ferment germs that appear in   
the  liquid are derived4 ,such are      
typical spontaneous fermentations1 and  
it  is of the ferment so obtained that  
we are about to speak4    ,in the course

 of the researches which we undertook in
 order to ascertain  whether mycoderma  
vini1 or vinous efflorescence1 became   
transformed1  in the case of beer1 into 
actual alcoholic ferment--researches    
which were  the more protracted and     
varied in consequence of their leading  
to the  condemnation as erroneous1 on   
the faith of new and more precise       
experiments1 such as those given in     
,chap4 ,,iv4  #b1 of that               
transformation1 in which we had for long
 believed--we had occasion to  observe  
several spontaneous fermentations of    
this kind in various  saccharine        
liquids4 ,we then proceeded to describe 
our method of  conducting the           
experiments4 ,having brought about the  
development of a  film of mycoderma vini
 or cerevisi on the surface of a liquid1
  fermented or not1 we submerged that   
film in wort1 which we afterwards  put  
into long-necked flasks1 in which       
alcoholic fermentation generally  took  
place in the course of a few days4 ,this

 fermentation in no way  resulted from  
the transformation of the cells         
constituting the  efflorescence into    
ferment4 ,the mycodermic film merely    
acted as a  receptacle of true ferment  
germs1 wafted thither with the particles
 of  dust floating in the air of the    
laboratory1 which germs developed in the
  liquid into actual alcoholic ferments 
amongst the cells of the submerged      
mycoderma4 ,by conducting experiments in
 this manner we brought about  several  
spontaneous fermentations1 the germs of 
which could have been  introduced by    
nothing but the particles of dust in the
 air4 ,these  fermentations1 which we   
were obliged to follow very carefully   
with the  microscope from the time when 
they first manifested themselves1 on    
account of the transformation that we   
were seeking1 which transformation  we  
thought might possibly be that of the   
cells of mycoderma vini into  cells of  
ferment1 generally gave us during the   
first days of  fermentation the large1  

elongated1 branchy ferment represented  
in ,plate  ,x41 which was succeeded by  
the small ferment represented in ,plate 
,,xi4#ii    ,illustration3 ,plate #ab4  
,ferment-cells from a ,spontaneous      
,fermentation  just starting4    ,here  
let me describe one of these            
experiments4 ,in the beginning of       
,march1 #ahgb1 we grew some mycoderma   
vini1 obtained from wine1 on some  wort 
contained in a shallow basin4 ,on ,march
 #fth we submerged the  efflorescence   
and put it all together1 liquid and     
film1 into a  long-necked flask4 ,on    
,march #ith we detected incipient       
fermentation1 and  on ,march #abth we   
took a sketch of the yeast of the       
deposit1 as given in  ,plate ,,xii4     
,this is the large and long branching1  
more or less  pear-shaped form1 which   
occurs at the beginning of fermentation 
in the  sweet and acid musts of our     
domestic fruits4 ,on ,march #afth we    
made  another sketch of the deposit1 in 
which the proportion of cells1 in the   

form of elongated segments and          
filaments1 reminded us1 in some measure1
  of the filamentous mycelium of typical
 fungoid growths much diminished4  ,in  
this case1 however1 the majority of     
cells were oval1 round1 and in  short   
segments4 ,on this day1 ,march #afth1 we
 added some fresh wort to  that which   
had fermented1 with the object of       
prolonging the duration of  fermentation
 and increasing the proportion of yeast4
 ,on ,march #aith we  made a fresh      
sketch1 which it is not necessary either
 to reproduce2  suffice it to say1 that 
the yeast was now considerably more     
regular and  uniform in appearance4     
,illustration3 ,fig4 #ch4               
,spontaneous ferment1 therefore1 very   
often occurs in this large              
ferment-form1 which1 by repeated        
developments in the act of              
fermentation1 becomes reduced by degrees
 after successive generations to  the   
ferment which1 following ,dr4 ,rees1 we 
have named saccharomyces  pastorianus1 a

 polymorphous ferment which must be     
studied closely that  it may not be     
confounded with others1 inasmuch as it  
is so universally  diffused that we very
 seldom fail to find it in any ferment  
which has  been exposed in contact with 
ordinary air1 at least1 we may repeat1  
in a  laboratory devoted to researches  
on fermentation4 ,we have found the same
  thing occur in a brewery1 being there 
mixed with the ferments used in         
brewing4    ,there are1 no doubt1       
several varieties of this saccharomyces4
 ,we  sometimes find amongst the        
spontaneous ferments which repeated     
growths  have brought to a more or less 
uniform state1 the forms represented in 
,plate ,,xi41 but the cells and segments
 much smaller4 ,amongst others1 ,dr4    
,rees has distinguished a saccharomyces 
exiguus4    ,fig4 #ch represents another
 spontaneous ferment1 which appeared in 
a  boiled saccharine wort1 which entered
 into fermentation after being  exposed 
to the air of the laboratory4    ,the   

sketch was made directly after the      
fermentation had commenced4  ,probably  
this is simply one of the earlier forms 
assumed by the  saccharomyces1 or by one
 of its varieties4 ,it will be seen that
 the  alcoholic ferment is associated   
with another little filiform ferment1   
probably the lactic4 ,the spontaneous   
ferments are almost always impure1  a   
circumstance that may be readily        
understood if we bear in mind the       
results described in ,chapters ,,iii4   
and ,,iv4                               
,,iii4--,on 8,high0 and 8,low0          
,ferments4      ,the ferments mentioned 
in the preceding paragraphs do not      
belong1  properly speaking1 to          
industrial products2 that is to say1 in 
actual  practice there are no operations
 in which the ferments of fruits and    
spontaneous ferments are employed for   
the purpose4 ,it is quite true that     
these ferments are the cause of the     
fermentations from which wine1  cider1  
gin1 rum1 gentiana1 mead1 c41 are       

derived1 but these  fermentations are   
spontaneous1 they take place without the
 intervention  of man1 and without man's
 directing their production1 or taking  
any  notice of the agent which starts   
them4    ,in the manufacture of beer1 on
 the other hand1 the practice is quite  
different4 ,we may say that the wort is 
never left to ferment  spontaneously1   
the fermentation being invariably       
produced by the  addition of yeast      
formed on the spot in a preceding       
operation1 or  procured from some other 
working brewery1 which1 again1 had at   
some time  been supplied from a third   
brewery1 which itself had derived it    
from  another1 and so on1 as far back as
 the oldest brewery that can be         
imagined4 ,a brewer never prepares his  
own yeast4 ,we have already had         
occasion to remark that the interchange 
of yeasts amongst breweries is a        
time-honoured custom1 which has been    
observed in all countries at all        
periods1 as far back as we can trace the

 history of brewing4 ,the yeasts  which 
in the present day produce beer in the  
brewery of ,tourtel1 near  ,nancy1 in   
that of ,grber1 at ,strasburg1 that of  
,dreher1 at ,vienna1 and  others1 came  
originally from breweries1 where and    
when it would be hard  to say4 ,in the  
case of the first working brewery1 the  
yeast was1 no  doubt1 derived from some 
spontaneous fermentation1 which took    
place in  an infusion of barley that had
 been left to itself1 or1 from some     
natural spontaneous ferment1 and nothing
 could be easier than to realize  this  
fact again4 ,in the brewing industry    
there are two distinct modes of         
fermentation3--8high0 fermentation and  
8low0 fermentation1 some of the         
distinctive characteristics of which we 
have pointed out in ,chapter ,i4  ,it   
may be questioned whether the           
spontaneous yeast employed in the first 
brewery1 or that which a wort left to   
itself in the present day would  yield1 
would be of the 8high0 or 8low0 type4   

,it may be concluded from  what we have 
said on the subject of spontaneous      
fermentations in wort1  that wort1 left 
to itself1 would furnish ferments more  
or less  resembling those of wine4 ,we  
have never obtained in spontaneous      
fermentations of wort either a          
distinctly 8high0 ferment1 or a         
distinctly 8low0 one1 properly so       
called2 nor1 further1 have we ever      
obtained either one of these distinct   
kinds1 with its industrial              
characteristics1 in experiments on the  
ferments of fruits4 ,what1 then1  was   
the origin of the 8high0 and 8low0      
ferments now used by brewers8  ,what was
 the nature of their original germs8    
,these are questions which  we are      
unable to answer1 but we are very much  
inclined to think that we  have here    
another example of the modifications    
which plants as well as  races of       
animals undergo1 and which become       
hereditary in the course of  prolonged  
domestication4 ,we know nothing of corn 

in its wild state1 we  cannot tell what 
its first grain was like4 ,we know      
nothing of the  silk-worm in its        
original state1 and we are ignorant of  
the characters  of the race that        
furnished the first egg4    ,these      
reflections may seem to favour the      
supposition that there is a  real       
difference between 8high0 yeast and     
8low0 yeast1 and that both of  these    
differ from spontaneous ferments and the
 ferments of domestic  fruits4 ,these   
are propositions demanding most careful 
consideration1 for  it is generally     
admitted that these ferments become     
intermixed1 that  their morphological   
differences are merely a question of    
medium1 and  that the transition of one 
to the other is a simple matter4 ,the   
following facts seem to contradict such 
statements4    ,illustration3 ,fig4 #ci4
    8,high0 ,ferment4--,fig4 #ci        
represents some 8high0 yeast taken from 
a  deposit after fermentation1 and ,fig4
 #dj the same yeast in course of        

propagation in some aerated wort4 ,in   
comparing 8high0 yeast with other       
alcoholic ferments at the same stage of 
development1 there are three  points    
which are especially striking3 the      
diameter of its cells is  relatively    
large1 their general aspect is rounder1 
and when they are  undergoing           
propagation their mode of budding       
produces a markedly  ramified           
appearance1 so that the cells always    
occur in clusters and  branches4 ,fig4  
#dj gives a very exact idea of these    
characters4 ,to  investigate            
satisfactorily the branching habit of   
growth peculiar to  this ferment we     
should examine it during the first few  
hours of its  propagation1 when1 under  
the influence of the oxygen dissolved in
 the  fermentable liquid1 its vital     
activity is greatest4 ,later on1 often  
on  the day following the sowing1 the   
groups become disconnected1 and at the  
end of the fermentation the cells have  
quite separated from each other1  not   

more than #b or #c per cent4 remaining  
united1 and even these in  groups of not
 more than two cells together4 ,this is 
represented in ,fig4  #ci4    ,to give  
an idea of the rapidity with which this 
ferment multiplies1 we  may state that  
our sketch 7,fig4 #dj7 was made under   
the following  conditions3--,on ,april  
#bhth1 #ahgd1 we caused a flask of wort 
to ferment by  means of a trace of      
8high0 yeast4 ,on the morning of the    
next day1 that  is fourteen hours       
afterwards1 an appreciable deposit of   
yeast had  formed1 and some frothy      
patches appeared on the surface of the  
liquid1  showing that fermentation had  
set in4 ,on ,may #ast we decanted the   
beer1  substituting for it water        
sweetened with #aj per cent4 of sugar4  
,on ,may  #bnd we decanted the sweetened
 water1 and substituted a fresh quantity
  containing the same percentage of     
sugar4 ,on ,may #crd1 at mid-day1 we    
took  some of the fermenting liquid from
 this flask and put it into a flask of  

wort2 five hours after the introduction 
of the ferment we made the  sketch in   
question4 ,the field is covered with    
branching clusters1 the  groups being   
sketched exactly as they occurred in the
 field4 ,their  activity was due to the 
condition of the ferment1 and to the    
perfect  fitness of the nutritive medium
 for its vegetation4 ,in sweetened water
  the budding of the cells was          
considerably less active2 no branching  
groups of cells are to be found4        
,budding1 nevertheless1 occurs to a     
considerable extent1 but it is limited  
to one bud1 or two at the most1  to each
 cell4 ,fermentation in pure sweetened  
water is mostly correlative  with the   
duration of vital activity in the       
globules already formed4                
,illustration3 ,fig4 #dj4    ,let us    
next suffer our yeast to exhaust itself 
by keeping it in a great  excess of     
sweetened water for a very long time2 we
 shall then be able to  observe its     
process of revival1 and see if we can   

find any facts  analogous to those      
presented by saccharomyces pastorianus  
7,chapter ,v4   #a74    ,with this      
object in view1 on ,may #fth1 #ahgd1 we 
impregnated two fresh  flasks of        
sweetened water with some of the        
contents of the  before-mentioned flask1
 which we had refilled with sweetened   
water on  ,may #bnd4 ,on ,may #acth we  
decanted the liquid1 which was still    
very sweet1  from one of these two fresh
 flasks1 which could hardly be said to  
have  fermented at all--the quantity of 
yeast in them being so small--and       
replaced it with some wort4 ,strange to 
say1 on the morning of the #adth  we    
found an appreciable growth of yeast1   
and a froth of carbonic acid  gas on the
 surface of the liquid4 ,the yeast      
therefore was not dead1  although its   
fermentative powers had been exhausted4 
,there was1 however1  no remarkable     
feature in connection with its revival1 
nor did we find  the slightest trace of 
any of the elongated ferment-form4 ,what

 we got  was simply the ramified groups 
of 8high0 yeast again1 in round cells1  
but nothing more4    ,fearing that our  
yeast might not have remained for a     
sufficient time in  the sweetened water 
for exhaustion1 we set aside1 for a     
whole year1 the  other flask which we   
had prepared on ,may #fth4 ,on ,may     
#afth1 #ahge1 we  decanted the sweetened
 liquid and replaced it with wort4 ,this
 time1  however1 there was no revival of
 the yeast2 it had perished4            
,fortunately1 we had also saved the     
flask of yeast and sweetened water      
which was prepared on ,may #bnd1 #ahgd1 
as already mentioned1 and in this  case1
 as will be seen1 the vitality of the   
yeast had not been  extinguished1       
doubtless1 in consequence of the        
formation of what we  shall presently   
designate by the name of arobian        
ferment4 ,on ,may  #afth1 #ahge1 we     
decanted the liquid from this last      
flask1 and replaced it  with wort4 ,on  
the next day the surface of the wort was

 covered with a  thin froth1 indicating 
the commencement of fermentation4 ,the  
microscope  revealed nothing            
extraordinary1 or indicative of the     
fermentation of any  special ferment4   
,to assure ourselves that our ferment   
had remained  8high10 we sowed some of  
it in a fresh flask of wort on ,may     
#aith1 and  then1 seven hours after     
impregnation1 submitting it to          
examination1 we  could find nothing but 
ramified groups in fine condition1      
without a  single elongated cell1       
indeed1 it would have been impossible to
 find a  more beautiful specimen of     
8high0 yeast1 or one of a more decided  
character4    ,it would seem1 therefore1
 that 8high0 yeast cannot1 under any    
circumstances1 assume the form and      
character of the ferment  saccharomyces 
pastorianus1 or of other known ferments4
 ,we are  justified1 therefore1 in      
regarding it as a distinct species of   
ferment1  an opinion which is supported 
by other circumstances4    #a4 ,in equal

 quantities of saccharine wort a        
considerably greater growth  of 8high0  
yeast is obtained than of other yeasts4 
,we need no very  rigorous proofs to    
convince ourselves of this fact3 for by 
simply  causing equal volumes of the    
same wort to ferment1 the one being     
pitched  with saccharomyces pastorianus1
 for example1 the other with 8high0     
yeast1 we shall obtain a perceptibly    
greater volume of 8high0 yeast than  of 
the other1 in certain cases even five or
 six times as much4    #b4 8,high0 yeast
 is of a tougher texture than the       
others1 separating1  when the fermented 
liquor and its deposit is shaken up1    
into lumps which  refuse to disappear2  
whereas saccharomyces pastorianus       
diffuses  through the whole liquid with 
the greatest ease4    #c4 8,high0 yeast 
produces a special beer1 with a peculiar
 flavour1 well  known to consumers1 but 
little esteemed at the present day4     
,hence the  gradual displacement of     
breweries worked on the old 8high0      

fermentation  system by others in which 
8low0 yeast 7of which more anon7 alone  
is  employed4    #d4 ,lastly1 one       
characteristic of 8high0 yeast1 which it
 shares in common  with some other      
ferments1 although not with all1 and    
which1 from a  practical point of view1 
deserves special mention1 is that as    
fermentation proceeds the yeast rises to
 the surface of the liquid4  ,whilst the
 process of the manufacture of beer by  
this ferment is going  on1 the yeast is 
seen to work out of the bung-holes1     
flowing over in  considerable quantity4 
,the ferment named after the author1 as 
well as  8low0 yeast1 does not possess  
this property3 it remains at the bottom 
of  the vessels4 ,when 8high0           
fermentation takes place in vessels that
 are  not filled1 the ferment forms a   
thick layer1 a kind of cap on the       
surface of the beer4 ,this              
characteristic may be witnessed even in 
the  fermentation of very small         
quantities of liquid4 ,in our flasks1 in

 which  the volume of fermenting wort   
does not exceed #ajj c4c4 or #aej c4c4  
7about #d or #e fluid ounces71 we may   
perceive1 as the violence of            
fermentation subsides1 and the head     
falls1 the sides of the vessel  covered 
to a height of from #a cm4 to #b cm4    
7about #c_/d-;in47 above the  surface of
 the liquid1 with particles of yeasty   
matter1 in little  masses1 or in a thin 
film1 raised to that height by the head1
 and left  behind when that fell4       
8,low0 ,ferment4--,whilst high yeast    
performs its functions in the breweries 
in which it is used at somewhat high    
temperatures--namely1 between #af ,c4   
and #bj ,c4 7#fj ,f4 to #fh ,f47--8low0 
yeast is never employed at a higher     
temperature than #aj ,c4 7#ej ,f471 and 
it is even thought preferable that  it  
should not be subjected to more than #f 
,c41 #g ,c41 or #h ,c4 7#dc ,f4  to #df 
,f474 ,at these comparatively low       
temperatures 8high0 yeast would  have no
 perceptible action1 whereas it is at   

such temperatures that  8low0 yeast best
 performs its functions4    ,in our     
,memoir on alcoholic fermentation1      
published in #ahfj1 in the  ,annales de 
,chimie et de ,physique1 the idea of the
 identity of the two  yeasts was        
accepted2 but we had at that time made  
no special  observations of our own on  
the subject4    ,upon closer            
investigation we are inclined to believe
 that the two yeasts  are quite         
distinct4 ,we might keep our 8high0     
yeast at the lowest  temperatures that  
it can bear1 and repeat our growths     
under these  conditions2 or1 on the     
other hand1 we might subject the 8low0  
yeast to  temperatures higher than those
 at which it ordinarily grows1 without  
ever succeeding in changing the first   
into the second or the second into  the 
first1 supposing1 of course1 that each  
of our yeasts was pure to  begin with4  
,if they were intermixed the change in  
the conditions of  development would    
cause one or the other to preponderate1 

and incline us  to believe that a       
transformation had really occurred4     
,illustration3 ,fig4 #da4    ,it is true
 that brewers generally are of a        
different opinion4 ,most of  them assert
 that 8low0 yeast cultivated at a high  
temperature becomes  8high0 yeast2 and  
conversely1 that 8high0 yeast becomes   
8low0 by  repeated growths at a low     
temperature4 ,many have told us that    
they have  proved this4 ,nevertheless it
 is our belief that the success of such 
transformation has been but apparent1   
attributable in each case to the  fact1 
as we have just stated1 of their having 
operated on a mixture of  the two       
yeasts4    ,mitscherlich1 and various   
authors after him1 have asserted that   
8high0  yeast propagates by budding1 and
 8low0 yeast1 on the contrary1 by       
spores1 formed by the endogenous        
division of the protoplasm of the       
cells1 and set free by the rupture of   
the cell-wall1 which then1  increasing  
in size1 assume the character of        

ordinary cells4 ,but we have  never been
 able to confirm this4    ,fig4 #da     
represents a field of low yeast1 taken  
from the deposit in a vat  after the    
fermentation of the beer was finished4  
,the granular matter  mixed with the    
cells is altogether amorphous although  
in many cases  perfectly spherical4 ,it 
is a product in no way related to this  
yeast  7see ,plate ,i41 ,no4 #g74ajj    
8,high0 yeast and all the ferments of   
beer  have this kind of deposit         
associated with them4 ,there is no doubt
 that  confused observations as regards 
these minute bodies have been the cause 
of the error which we had to deal with  
in connection with a particular  mode of
 reproduction of low yeast1 as to which 
we have already fully  expressed our    
views 7,chap4 ,v4  #a1 p4 #adf74        
,comparing ,fig4 #da with ,fig4 #dj 7p4 
#ahi71 it may be seen that the general  
aspect of low yeast is distinguished1 in
 its early stages1 although in  no very 
decided manner1 from that of 8high0     

yeast1 by being slightly  smaller and   
less round or spherical in its cells    
than the latter4#aja  ,these            
differences1 however1 would escape an   
unpractised eye4    ,as to the case of  
8high0 yeast1 the deposits of 8low0     
yeast after  fermentation appear as     
scattered1 isolated cells2 we do not    
find more  than two or three per cent4  
of united cells4 ,nevertheless the two  
yeasts  present1 as we shall see1 quite 
marked differences in the character of  
their budding and multiplication4       
,illustration3 ,fig4 #db4    ,on ,may   
#bhth1 #ahge1 we put a trace of pure1   
unicellular1 8low0 yeast1  taken at the 
end of a fermentation1 into a flask of  
wort4 ,on ,may #bith1  sixteen hours    
after impregnation1 the temperature     
during the night  having been #ae ,c4   
7#ei ,f471 we made a sketch of the yeast
 before its  development had become     
apparent to the naked eye4 ,no          
perceptible  development1 that is to    
say1 no visible deposit at the bottom of

 the  liquid and formation of patches of
 froth on the surface1 took place       
before ,may #cjth4 ,a mere glance at    
,fig4 #db will be sufficient to enable  
us to detect a considerable difference  
between it and ,fig4 #dj1 which         
represents the multiplication of the    
cells of 8high0 yeast4 ,the cells of    
the 8low0 yeast are slightly smaller and
 rather more oval1 as we have  already  
had occasion to notice1 and the budding 
processes are  considerably less        
ramified1 in consequence of which there 
is a  comparative absence of globular   
clusters which are so striking a feature
  in the development of 8high0 yeast1   
when examined early enough4  ,moreover1 
if we cause our 8low0 yeast to age1 by  
leaving it for a longer  or shorter time
 in the beer which it has formed1 or if 
we exhaust it in  sweetened water by    
leaving it for whole months in a volume 
of sweetened  water considerably larger 
than what it is capable of fermenting1  
and  then proceed to revive it and cause

 it to propagate in an aerated          
saccharine wort capable of nourishing   
it1 this yeast will resume its  original
 aspect1 as sketched and described4 ,at 
most we shall observe  certain minute   
differences in the size of the cells in 
successive  growths4 ,a very remarkable 
industrial characteristic of this yeast 
is  the fact that it never rises to the 
surface1 no matter at what  temperature 
it may be working1 whether between #f   
,c4 and #h ,c4 or #ae ,c4  and #bj      
,c42#ajb in other words1 it is not      
buoyed up by the carbonic  acid gas when
 the fermentation is at its height4 ,at 
the end of the  fermentation1 the       
surface of the liquid and the sides of  
the vessel  above the level of the      
liquid are clean and not covered with   
the yeast1  which remains altogether at 
the bottom of the fermented liquid4     
,moreover1 the weight of new yeast which
 it yields is always less than  that    
yielded by 8high0 yeast1 for the same   
quantity of fermentable  liquid1        

although greater than that which        
saccharomyces pastorianus  would give4  
,lastly1 the beer possesses a flavour   
and delicacy which  cause it to be held 
in higher esteem by consumers than beers
 produced by  means of other            
ferments4#ajc          ,,iv4--,on the   
,existence and ,production of ,other    
,species of ,ferment4      ,our present 
knowledge of the alcoholic ferments     
embraces the following1  without taking 
into account the ferment-form of        
mucor3--    ,the ferment named after the
 author1 which is found associated with 
the  ferments of the grape and other    
domestic fruits1 and with spontaneous   
ferments in general4    ,the ferment of 
8high0 beer4    ,the ferment of 8low0   
beer4    ,to these must be added the    
ordinary ferment of wine1 and that      
called  apiculatus1 although1 indeed1   
these last are of little practical      
importance1 since1 in general1 they soon
 become lost amongst others of  greater 
vitality1 in the spontaneous            

fermentation of fruits4 ,these are  not 
the only alcoholic ferments2 a study of 
the germ-cells diffused over  the       
surface of fruits1 grains1 and stalks of
 all vegetables in different  countries1
 would doubtless lead to the discovery  
of many new ones4 ,we  are even inclined
 to believe that one ferment might give 
rise to a  multitude of others4 ,the    
investigations which we have undertaken 
in this  direction are as yet not far   
advanced2 we may1 however1 be allowed   
merely to state the principle which     
governs them4 ,a ferment is a           
combination of cells1 the individuals of
 which must differ more or less  from   
each other4 ,each of these cells has    
certain generic and specific            
peculiarities which it shares with the  
neighbouring cells2 but over and  above 
this1 certain peculiar characteristics  
which distinguish it1 and  which it is  
capable of transmitting to succeeding   
generations4 ,if1  therefore1 we could  
manage with some species of ferment to  

isolate the  different cells that       
compose it1 and could cultivate each of 
these  separately1 we should obtain as  
many specimens of ferments1 which would1
  probably1 be distinct from one        
another1 inasmuch as each of them would 
inherit the individual peculiarities of 
the cell from which it  originated4 ,our
 endeavours are directed to realizing   
this result  practically1 by first      
thoroughly drying a ferment and reducing
 it to  fine powder4 ,we have seen      
7,chap4 ,,iii4  #f7 that this mode of   
experiment  is practicable1 that in a   
powder composed of yeast and plaster the
  ferment preserves its faculty of      
reproduction for a very long time4 ,if  
we now drop a small quantity of this    
powder from a sufficient height1  and   
then1 at a certain distance below the   
cloud of dust so formed1 open  several  
flasks previously deprived of air and   
containing a fermentable  liquid that   
has been boiled1 immediately closing    
them all up again1  under such          

circumstances it is conceivable that    
some of the cells of  yeast diffused in 
the cloud of dust1 and separated widely 
in the act of  falling1 will enter some 
of our flasks singly1 and there develop 
an  appreciable weight of ferment1 all  
the cells of which will have sprung     
from the same mother-cell4 ,we have     
proved that flasks may be easily        
impregnated under these conditions1 and 
our preliminary observations1  although 
incomplete1 seem to favour the idea that
 numerous varieties of  ferment are to  
be obtained by these means4             
,spontaneous ferments1 properly so      
called1 of which we have already        
spoken1 are1 after all1 the result of   
sowings of this kind4 ,originating  in  
liquids which have been boiled1 and then
 left to themselves in  contact with the
 air in a place where cells or germs    
must have existed1  these ferments must 
necessarily often spring from single    
germs or from a  limited few1 and this  
also would probably be a means of       

developing  distinct varieties of       
ferments4    ,without dwelling longer on
 the practical consequences likely to   
result  from the ideas which we have    
just expressed1 we shall proceed to     
describe two new alcoholic ferments1    
which differ widely from those  already 
mentioned4    ,new 8,high0              
,ferment4--,we met with this ferment    
accidentally1 under the  following      
circumstances3--,on ,february #abth1    
#ahgc1 we had brewed in the  laboratory 
about #b- hectolitres 7rather over #ej  
gallons7 of wort1 #aj  litres 7about two
 gallons7 of which were set aside to    
cool in a  white-iron trough1 and left  
during the night exposed to free contact
  with air in the underground part of   
the laboratory1 where we have a  small  
experimental brewery4 ,next day we put  
some of this latter into a  bottle2 the 
wort soon began to show evidence of     
change1 various  productions made their 
appearance on the surface of the liquid1
 and a  deposit of yeast settled at the 

bottom4 ,on ,may #bcrd1 perceiving      
bubbles  of gas and a steady            
fermentation set up in the wort1 which  
remained all  the time corked up1 and   
fearing that the bottle might burst by  
the  increasing internal pressure1 we   
drew the cork4 ,a considerable          
liberation of gas at once took place1   
accompanied by a voluminous foam  which 
half emptied the bottle4 ,a             
microscopical examination of the        
deposit from the disturbed liquid led to
 the discovery of a very  homogeneous   
yeast1 associated with various other    
organisms2 it was  clearly a yeast which
 we had not hitherto met with amongst   
the  spontaneous ferments which we had  
had occasion to study4 ,thinking that   
this might be a new species of ferment  
which would probably produce a  beer    
that was also unknown1 we set to work to
 purify it by cultivation  in flasks of 
pure wort1 during the months of ,may1   
,june1 and ,july4 ,our  last growths1 of
 ,august #dth1 #ahgc1 were preserved1 in

 order that we  might assure ourselves  
of the purity of the beer1 and1         
consequently1 of  the ferment4 ,on      
,november #aeth its purity was          
established4 ,on that date  we made some
 beer with this ferment1 which had now  
been left to itself  for several months 
in contact with pure air4 ,the beer     
which we obtained  resembled no known   
variety2 consequently the ferment must  
itself have  been a distinct one1       
differing from others1 especially those 
which we  have been considering in this 
chapter4    ,illustration3 ,fig4 #dc4   
,fig4 #dc represents the rejuvenescence 
of this ferment4 ,comparing this  figure
 with ,fig4 #db1 we see that this       
ferment presents a considerable         
resemblance to 8low0 yeast in           
dimensions1 method of budding1 and oval 
shape2 but the feature which            
distinguishes it essentially from 8low0 
yeast is that it rises to the surface1  
like 8high0 yeast4 ,buoyed up by  the   
gas during fermentation1 it forms a     

layer of yeast on the surface of  the   
fermenting liquid1 where it remains     
after the head has fallen4 ,some  of    
this head of yeast likewise adheres to  
the sides of the vessel above  the level
 of the liquid4    ,in short1 by the    
greater regularity of its forms and the 
uniform  dimensions of its cells1 this  
ferment is to be easily distinguished   
from  saccharomyces pastorianus2 its    
aspect1 which is oval instead of        
spherical1 and the ramified form of its 
chains of cells1 which is less  marked  
than in the case of 8high0 yeast1 also  
prevent our confounding it  with the    
latter ferment2 in its rising character 
it differs absolutely  from 8low0 yeast2
 lastly1 it may be distinguished from   
all other  ferments by the flavour of   
the beer that it produces4    ,the      
ferment which we discovered in this     
accidental way may be utilized4         
,indeed1 we may ask1 is it not to be    
found already in our beer8 ,we are      
inclined to believe that it is4 ,after  

the war of #ahgj1 some ,viennese        
traders established at ,maisons-,alfort1
 near ,paris1 a manufactory of  yeast   
for bakers4 ,they saccharified by means 
of malt a mixture of the  meals of rye1 
maize1 and barley1 which they then      
caused to ferment4 ,one  day we had     
occasion to study the yeast produced in 
this establishment1  and although we did
 not submit it to a sufficient number of
 consecutive  experiments to enable us  
to speak positively1 we are under the   
impression that the yeast produced at   
,maisons-,alfort is a 8high0 one1       
differing from what may be properly     
termed the 8high0 yeast of breweries  in
 which 8high0 fermentation is practised1
 but presenting a great  resemblance to 
the 8high0 yeast of which we have been  
speaking4 ,it would  be interesting to  
confirm the opinion of their possible   
identity by  fresh studies1 and the best
 way of doing this would be to compare  
the  qualities of beer which the two    
yeasts could produce4    ,caseous       

,ferment4--,we give the title caseous   
for a reason that will  presently       
appear1 to a ferment which we came      
across also accidentally4  ,we were     
trying different methods of purifying   
yeasts1 and for this  purpose had       
composed a liquid formed of3            
,ordinary wort                          
#aej c4c4#ajd        ,water saturated   
with bi-tartrate of potash    #ej c4c4  
,alcohol of #ij                         
#be c4c4    ,quantities of this liquid  
were placed in several of our           
double-necked  flasks1 submitted to     
boiling1 then1 after cooling1           
impregnated with  different ferments1   
and kept in a water-bath at #ej ,c4     
7#abb ,f47 for one  hour4    ,in        
operating under these conditions with   
brewers' 8high0 yeast1 say1 for         
instance1 with what is called ,dutch    
yeast1 a kind well known in             
distilleries1 fermentation shows itself 
in the course of a few days1 in  spite  
of the increased temperature to which   

our liquid1 which is hopped  and        
slightly acid and alcoholic1 has been   
subjected4 ,the time required  for the  
resumption of fermentation depends both 
upon the degree of  temperature to which
 the yeast has been exposed and upon the
 duration of  its exposure4 ,these1     
however1 are not the points upon which  
we now wish  to dwell4 ,it is of greater
 importance to notice that the new yeast
 has  none of the characteristics of    
8high0 ferment1 of which ,dutch yeast   
seems to be exclusively composed1 if we 
do not take into account  impurities    
which cannot be avoided in a commercial 
product of this  nature4 ,other         
specimens of ,dutch yeasts would give   
the same results4    ,illustration3     
,fig4 #dd4    ,illustration3 ,fig4 #de4 
,figs4 #dd and #de represent this new   
ferment magnified to the same extent  as
 the other ferments have generally been1
 that is #djj_/a2 it will  readily be   
seen how different its form is from that
 of 8high0 yeast1 how  far it is from   

having the spherical aspect and mode of 
budding  characteristic of that ferment4
 ,in ,fig4 #de the ferment is           
represented in  a mass2 in ,fig4 #dd we 
see the ramified groups1 the cells and  
segments of  which form1 after          
separation1 the yeast of the deposit4   
,it thus appears  to be composed of     
jointed branches of greater or less     
length1 which1 at  the junctions of the 
segments1 put forth similar cells or    
segments of a  round1 oval1 pyriform1   
cylindrical1 or other shape2 in all its 
characters recalling the description of 
dematium4 ,moreover1 the cells  and     
segments exhibit a greater sharpness of 
outline1 as well as a more  marked      
transparency and refractive power than  
are found in the majority  of ferments2 
but the most curious physical           
characteristic of this  ferment is its  
plasticity and elasticity1 if we may use
 those terms4 ,it  can only be made to  
diffuse through water with great        
difficulty2 when  shaken up in it1 it   

sinks to the bottom quickly as a clotted
 sediment1  and the supernatant liquid  
appears scarcely at all charged with    
globules  in suspension4 ,again1 when   
placed on a microscope slide and        
compressed  by the cover-glass1 it      
returns to its original form on removal 
of the  pressure4 ,it is from these     
considerations that we have given to it 
the  name of caseous ferment4#aje       
,lastly1 this ferment produces a beer of
  a peculiar kind1 which cannot be      
confounded with other kinds of beer     
known in the present day4 ,we should add
 that it preserves its  characteristics 
in repeated growths1 and that we have   
never found it  reproduce ordinary      
8high0 yeast4    ,when caseous ferment  
is sown in a saccharine medium charged  
with mineral  salts1 its aspect1 form1  
and mode of budding differ completely   
from what  they are when the ferment    
exists in a natural medium1 such as wort
 or  other liquid adapted to the        
nutrition and life of ferments4         

,illustration3 ,fig4 #df4    ,fig4 #df  
represents this ferment in course of    
development1 forty-eight  hours after it
 had been sown in a saline medium 7we   
employed ,raulin's  fluid1 substituting 
bi-tartrate for the nitrate of ammonia74
 ,it will be  seen how different its    
aspect is from that of the preceding    
figures2 it  is still capable1 however1 
of resuming the forms of the latter if  
cultivated afresh in natural saccharine 
worts4    8,high0 yeast from a 8high0   
fermentation brewery in the ,ardennes1  
after  having been exposed to heat under
 the conditions given above1 likewise   
produced caseous ferment1 without a     
trace of 8high0 ferment1 just as        
happened in the case of the ,dutch      
yeast4 ,all the 8high0 yeasts used in   
brewing seem to behave in the same      
manner4    ,what conclusion are we to   
draw from these facts8 ,apparently that 
8high0  yeast is modified by heat in an 
acid and alcoholic medium1 giving rise  
to caseous ferment4 ,on the other hand1 

it might be conceived that the  8high0  
yeasts on which we experimented were not
 pure1 but contained1 in  a state of    
intermixture1 some caseous ferment1 and 
that by the  application of a           
temperature of #ej ,c4 7#abb ,f47 to our
 alcoholic  medium1 the high ferment was
 all killed and the caseous ferment     
alone  survived4 ,it is a remarkable    
fact that this latter hypothesis1       
improbable as it seems1 inasmuch as the 
microscope revealed no  intermixture of 
ferments1 seems1 nevertheless1 to be a  
true one4 ,as a  matter of fact1 if we  
subject to a temperature of #ej ,c4 for 
one hour in  the medium in which it     
acts1 not the 8high0 yeast of commerce  
but 8high0  yeast that is absolutely    
pure1 this will perish utterly1 and the 
wort  after cooling may remain for years
 in an oven without either undergoing   
fermentation or developing any growth   
whatever of 8high0 ferment or  8caseous0
 ferment4    ,on the other hand1 if we  
impregnate this same alcoholic liquid   

with some  of the caseous ferment and   
then heat the vessel to #ej ,c4 for one 
hour1  the caseous ferment will go on   
reproducing itself after the liquid has 
cooled down4#ajf    ,it seems1          
therefore1 impossible to admit that     
caseous ferment results  from a         
modification of 8high0 ferment1 and we  
are led to believe that in  the         
preceding experiments it must have been 
the progeny of cells of  caseous ferment
 present in the 8high0 yeasts of        
commerce1 which cells1  probably in     
consequence of their scarcity1 the      
microscope was unable to  reveal1 but   
which1 nevertheless1 did exist1 and went
 on reproducing  themselves alone after 
the heating4    ,illustration3 ,fig4    
#dg4    ,this conclusion is supported by
 the following fact1 which also tends to
  prove that in the case of the 8high0  
,english pale ales1 caseous  ferment    
plays a most important part4 ,in the    
medium already described1 we  sowed the 
deposit from a bottle of good ,english  

pale ale4 ,after having  been heated the
 yeast went on growing1 and we obtained 
the very  beautiful specimen of caseous 
ferment represented in ,fig4 #dg4 ,the  
two  dark globules are dead cells which 
had been killed4 ,two minute segments   
of lactic ferment are also visible in   
the sketch--the yeast which we  sowed   
was1 of course1 impure--and their       
presence proves1 we may observe1  by the
 way1 that lactic ferment also can      
withstand a temperature of #ej  ,c4     
7#abb ,f47 in the medium which we here  
employed4 ,the yeast as sowed is        
represented in ,fig4 #dh2 it reminds us 
forcibly of certain forms of the        
caseous ferment4 ,amongst the globules1 
which for the most part were            
transparent and very young1 there were  
some which appeared aged and of a       
yellowish colour and granular4 ,these   
latter probably belonged to the  yeast  
of manufacture4 ,their shape            
distinguishes them from 8high0 yeast1   
properly so called1 as on the other hand

 it causes them to appear more  like    
cells of a recent growth to which1 there
 is no doubt1 beer1 after  it is put in 
bottle1 owes its effervescence and head4
 ,these various  circumstances incline  
us to believe that the caseous ferment  
forms part  of certain commercial       
yeasts1 especially those used in the    
celebrated  breweries of ,bass and      
,allsopp1 at ,burton-on-,trent1 in the  
manufacture of  pale ale4 ,caseous yeast
 is1 moreover1 a 8high0 ferment1 that is
 to say1  it rises to the surface4      
,illustration3 ,fig4 #dh4               
,v4--,on a ,new ,race of ,alcoholic     
,ferments3 ,arobian ,ferments4          
,mention has already been made of       
certain researches which we undertook   
with the object of ascertaining whether 
mycoderma vini1 or  efflorescence of    
wine1 and mycoderma cerevisi1 or        
efflorescence of  beer1 which grow      
equally well in all fermented liquids1  
have the power  of becoming transformed 
into actual alcoholic ferment4 ,the     

result of  those researches was stated  
to be that these mycodermata do not     
become  transformed into ferment1       
properly so called1 and that whenever   
any such  transformation has been       
supposed to have taken place1 the       
ferment  produced was derived from germs
 introduced by the air or by the        
utensils  employed4 ,what we did        
ascertain of the ferment-producing power
 of  mycoderma vini1 was merely that    
this plant1 when submerged1 is capable  
of causing sugar to ferment1 in         
consequence of a certain continuous life
  possible to its cells1 apart from the 
oxidations resulting from the  presence 
of free oxygen1 but without any         
generation of new cells taking  place4  
,whilst engaged in these researches1 we 
were pursuing others in relation  to the
 converse of the proposition just       
discussed1 that is to say1  respecting  
the possibility of ferment becoming     
transformed into  mycoderma vini or     
mycoderma cerevisiae4 ,our experiments  

in  connection with this subject chiefly
 consisted in various endeavours by  way
 of exhausting the yeast and subsequent 
revival of its growth4 ,this  exhaustion
 was effected by growing the yeast in   
excess of sweetened  water1 and at other
 times in unsweetened yeast-water1 our  
efforts being  directed to deprive it of
 all power of fermenting4 ,we afterwards
 caused  it to develop afresh in highly 
aerated1 nutritious liquids1 in order   
that we might see how it reproduced     
itself1 and if its new form were  that  
of a mycoderma4 ,the yeast after having 
lost its power as a ferment1  and being 
no longer able to act in pure sweetened 
water1 nevertheless  reproduced itself  
when placed in fermentable media1       
holding in solution  materials adapted  
to its nutrition2 yet we never succeeded
 in obtaining  any organism besides the 
ferment1 and1 indeed1 the identical     
variety of  ferment on which we had     
operated4 ,in no case was mycoderma vini
 or  cerevisi produced1 and we concluded

 that we were justified in stating  that
 whenever the mycoderma vini appeared on
 the surface of a  fermented or         
fermentable liquid1 its germ must have  
been introduced by  the surrounding air1
 or have previously existed in the      
liquid1 and that  the reason why this   
germ multiplied so abundantly was       
because the liquid  in question had been
 peculiarly adapted to the vitality of  
the plant4    ,in a laboratory where    
alcoholic fermentations are studied1    
these germs  of mycoderma vini exist in 
great abundance on the surfaces of      
different objects4 ,this fact admits of 
easy proof2 we have merely to  open in  
such a laboratory some flasks containing
 yeast-water deprived of  air1 or       
yeast-water sweetened1 or any natural   
saccharine medium1 or any  fermented    
liquid1 which till the moment when our  
flasks were closed had  been kept       
boiling 7,chap4 ,,iv472 it would be a   
very rare thing1 indeed1 if  mycoderma  
vini did not develop in most of these   

flasks after the air  was readmitted1   
especially if1 shortly before this      
operation1 the dust  lying on the       
surface of the tables or floor of the   
laboratory had been  stirred up by      
dusting or sweeping4    ,this series of 
experiments1 the salient points of which
 we have just  given1 conducted with a  
view to ascertain whether yeast could be
  transformed into mycoderma1 has led   
the way to certain results of  special  
interest1 results which concern all     
alcoholic ferments1 and  which in all   
probability will be found in the long   
run to apply to all  arobian ferments4  
,it being necessary for the conduct of  
our experiments to preserve our  yeast  
in a state of purity for an indefinite  
period1 often for a great  length of    
time1 in contact with pure air1 we      
discovered that yeast was  possessed of 
extraordinary vitality1 and that it     
rarely perished  completely throughout1 
inasmuch as we could almost invariably  
cause it  to revive by bringing it into 

contact with fresh1 fermentable liquid4 
,this revival of the yeast--and it is to
 this point that we are most  anxious to
 direct the attention of our readers--is
 effected from two  distinct sources3-- 
#a4 ,by those cells of yeast which have 
not perished4    #b4 ,by cells of new   
formation4    ,we may give an example to
 explain this more clearly4 ,in one of  
our  two-necked flasks we cause some    
pure wort to ferment by employing yeast 
also in a state of purity4 ,fermentation
 completed1 we leave the liquid  to     
itself1 not touching the flask again4   
,the fermented liquor covers a  deposit 
of yeast1 apparently inert1 and no trace
 of mycoderma vini  makes its appearance
 on the surface of the liquid4 ,let us  
suppose that  we go on daily for a      
considerable time introducing a little  
of the yeast  from this flask to a      
different flask of wort3 the fresh      
flasks will  begin to ferment4 ,the only
 appreciable difference which these     
successive  flasks will present1 their  

impregnation having been effected at    
intervals of twenty-four hours1 will be 
that1 ceteris paribus1  fermentation in 
them will be more and more slow in      
making its  appearance4 ,this           
difference1 as we have already          
explained1 will be due  to the fact that
 the yeast in the first flask will1 in  
the course of  time1 undergo1 in each of
 its cells1 a process which we cannot   
better  describe than as a progressive  
senescence4 ,the cells gradually become 
filled with amorphous granulations1     
their interior becomes yellow1 and  the 
protoplasm collects1 either at the      
centre or near the borders2 in  short1  
the vitality of the yeast becomes       
feeble4 ,when1 however1 it is  taken out
 of the liquid in which it has fermented
 and introduced into a  fresh saccharine
 wort1 it gradually resumes its         
transparency1 and then  begins to       
germinate4 ,these effects are the less  
rapidly brought about  the longer the   
cells remain exhausting themselves in   

the first fermented  liquid4 ,they might
 be left in that liquid for such a      
length of time that  they would         
eventually perish1 a fact which would   
manifest itself in  their absolute      
sterility and quiescence when sown in a 
fresh medium4 ,in  general1 however1    
matters are not carried far enough for  
this to take  place1 and the yeast1     
preserved in a state of purity in its   
fermented  liquid1 retains the capacity 
of revival1 which may then go on        
indefinitely4 ,as a matter of           
observation1 the cells of yeast1 after  
causing the liquid to ferment1 instead  
of remaining inactive1 and so by  living
 at their own expense gradually passing 
into a state of  exhaustion1 begin to   
bud again2 at least this is true of many
 of them4  ,multiplying afresh in the   
fermented medium1 under the influence of
 the  air1 they form a kind of          
mycodermic film on the liquid surface1  
or a  ring round the sides of the flask1
 on a level with the liquid4 ,this      

development might often be mistaken for 
mycoderma vini or cerevisi2  in reality 
there is not a single cell of mycoderma 
formed4 ,if we sow a  trace of the new  
growth in a saccharine medium it will   
behave exactly as  yeast would1 budding 
and multiplying1 and setting up         
fermentation in the  liquid4 ,and thus1 
in spite of its mycodermic aspect1 this 
growth is  nothing but yeast1 since it  
gives rise to true alcoholic            
fermentation2  but it is a kind of yeast
 which1 under the foregoing conditions1 
lives  after the manner of fungoid      
growths1 absorbing the oxygen of the air
 and  emitting carbonic acid gas4 ,it   
appears on the surface of all fermented 
liquids1 especially those which1 like   
beer1 contain carbohydrates1 and  its   
quantity is the greater1 and its action 
the more rapid1 in  proportion as it has
 more perfect access to the air4 ,we    
have termed this  yeast arobian ferment 
or fungoid ferment4    ,it may easily be
 understood how this kind of production 

has escaped  notice up to the present   
time4 ,the conditions of our experiment 
were1 in  many respects1 novel2 a       
saccharine liquid had never before been 
caused  to ferment by means of pure     
yeast1 absolutely free from foreign     
germs2 a  fermented liquid had not      
previously been exposed to contact with 
pure  air for an indefinite time4 ,on   
the other hand1 all ordinary fermented  
liquids1 when left to themselves in     
contact with air1 are a ready prey  to  
mycoderma vini or aceti at their        
surface1 and then give rise to  true    
fungoid growths4 ,the appearance of     
these organisms1 which always  takes    
place soon1 has thus constantly         
concealed or prevented the  development 
of the true arobian ferments4 ,in       
repeating the experiment  described any 
alcoholic ferment may be used1 and each 
one will be found  to produce its own   
peculiar fungoid form of ferment4       
,another point  worthy of notice is that
 these arobian ferments1 when they put  

forth  buds in the act of fermentation1 
reproduce the forms of the original     
ferment1 at least apparently so4 ,in    
this respect they cannot be             
distinguished1 notwithstanding the fact1
 surprising as it seems1 that  the two  
kinds of ferments are not identical4 ,if
 we operate on a 8low0  yeast its       
arobian ferment will differ             
physiologically from the ferment  from  
which it sprung1 presenting various     
special peculiarities which are  not to 
be found in the original 8low0 yeast4   
,in most of our experiments  we have    
found the new arobian ferment to be     
similar in its action to  8high0 yeast1 
rising to the surface1 and producing a  
beer which  possesses a greater         
fragrance than beer brewed with the     
identical 8low0  yeast from which it was
 derived4 ,lastly1 the properties of an 
arobious  ferment are not peculiar to   
first growth1 but are hereditary2 by    
repeating the growth of the first       
arobian ferment we do not cause them  to

 disappear1 we find them again in       
succeeding generations4                 
,notwithstanding these facts1 it would  
be difficult to discover any very       
appreciable differences between the     
forms of the cells of any particular    
yeast and those of its arobian ferment  
in course of development4 ,so  true is  
this1 that the arobian ferment of       
saccharomyces pastorianus  might even be
 caused to put on the forms of dematium 
pullulans1 which  we have had occasion  
to observe specially characterize this  
ferment  after the cells have been      
subjected to a prolonged process of     
senescence4#ajg ,this is evident from   
the following example1 which will  once 
again show the remarkable extent to     
which the forms of a particular         
organism may be varied by changes in    
composition of the nutritive  medium3-- 
,on ,august #fth1 #ahgc1 we took some of
 the ferment saccharomyces  pastorianus 
from a flask of wort that had undergone 
fermentation1 and  sowed a scarcely     

perceptible quantity of it in another   
flask containing  a saline medium1      
composed as follows3--         ,water   
containing about #aj per cent4 of       
#aej c4c4 7#e-a_/d fl4       sugar-candy
                                        
oz47         ,ash of yeast              
#je gramme 7#h grs47         ,ammonic   
bitartrate                        #jb   
8    7#c grs47         ,ammonic sulphate
                          #jb   0    7#c
 grs47    ,in the course of the         
following days the ferment began to     
develop1  although with difficulty1 the 
fermentation revealing itself by        
collections of bubbles appearing here   
and there on the surface of the  liquid4
 ,we left the flask undisturbed till the
 #beth of ,november  following4 ,on that
 day we found a very white deposit of   
ferment covering  the yeast-ash that had
 not been taken into solution1 and a    
ring of  arobian ferment on a level with
 the surface of liquid2 all the sugar   
had disappeared2 the liquid contained   

#eb per cent4 of alcohol1 by  volume1 at
 a temperature of #ae ,c4 7#ei ,f472    
and1 lastly1 in consequence  of the     
purity of the materials employed1 there 
was no trace of the  formation of       
fungoid growths1 whether of mycoderma   
vini or of  mycoderma cerevisi1 on the  
surface of the liquid1 or of vibrios or 
lactic-ferment below the surface4       
,thus then we see--and several other    
examples throughout this work confirm   
the fact--that saccharine liquids       
holding mineral salts in solution are   
as capable of complete fermentation as  
any media of natural composition4  ,it  
is true that ferment develops slowly and
 with difficulty in them1 and  at times 
takes on rather curious forms1 but1     
nevertheless1 it does  develop in the   
media and carry on a fermentation in    
which not the  minutest particle of     
sugar is left undecomposed4 ,this is    
true1 at least1  in the case of         
saccharomyces pastorianus1 but there are
 other ferments  which in such media are

 checked in their multiplication and in 
their  continued action on sugar4 ,one  
condition indispensable to the          
accomplishment of fermentation in such a
 sweetened mineral medium1 by  means of 
saccharomyces pastorianus1 is the       
absolute purity of the  materials and of
 the ferment4 ,it is necessary that the 
life and  physiological action of the   
latter should be in no way interfered   
with  by the presence of other          
microscopic organisms4 ,we shall have   
occasion  to revert to this important   
detail in connection with our growths4  
,illustration3 ,fig4 #di4    ,fig4 #di  
represents the ferment as it appeared   
when examined on ,august  #aath1 #ahgc4 
,we can no longer recognize in it any   
saccharomyces  pastorianus4 ,the general
 appearance is spherical1 and there are 
a  number of clusters of budding cells  
which remind one at first sight of  the 
mode of germination of brewers' 8high0  
yeast4 ,at a1 a1 a1 we  see globules    
from which irregular abortive filaments 

have sprung1 a  proof of difficult      
germination4 ,no such monstrosities     
could ever have  occurred if we had used
 beer-wort or must as our nutritive     
medium4    ,on ,november #beth we made  
another examination and sketch of the   
ferment1  the appearance of which did   
not differ materially from that given   
above4  ,the general appearance was the 
same1 consisting mostly of globules     
joined together in clusters of two or   
three or more4 ,no separation1 such  as 
occurs in the case of ferment formed in 
natural worts1 had taken  place4 ,the   
ferment1 moreover1 was very irregular1  
and comprised cells of  all sizes4 ,we  
sowed some of it in a flask of pure     
wort4 ,on ,november #bfth  there was no 
apparent development3 on ,november      
#bgth1 however1 not more  than          
forty-eight hours after impregnation1   
there was a considerable  deposit of    
white ferment at the bottom of the      
liquid1 and fermentation  was so active 
that the surface of the liquid was      

covered with an  abundant froth4 ,this  
shows us the wonderful vitality and     
recuperative  power possessed by germs  
which1 left to themselves for about four
  months1 revived so readily4 ,it proves
 too that the reviving influences  took 
effect on some arobian ferment4 ,from   
the mode of life of this  latter being  
similar to that of a surface fungoid    
growth1 it does not  become exhausted as
 the cells of ordinary ferment do4 ,now 
the cells  which1 sown on ,august #fth1 
had become exhausted by prolonged stay  
in the  mineral liquid1 and were almost 
inert1 would have required several days 
for their revival2 but in the experiment
 described the revival was  rapid1 and  
this rapidity proves1 as we have said1  
that the revival must  have taken place 
in cells of arobian ferment4            
,illustration3 ,fig4 #ej4    ,taking    
some fresh yeast from the bottom of the 
liquid we examined and  made a sketch of
 it 7,fig4 #ej74 ,the field was filled  
with round and oval  cells1 jointed and 

ramified filaments1 budding and         
multiplying in the  most remarkable     
manner1 reminding us of the germination 
of the cells of  yeast exhausted in     
sweetened water1 and also of the        
germination in the  form of dematium    
pullulans of certain germ-cells which   
are spread over  the surface of sweet1  
domestic fruits4 ,we could never grow   
tired1 as we  wrote it in our original  
notes1 of sketching this beautiful      
plant1 which  establishes very clearly a
 transition between one of the best     
defined  cellular ferments1 viz41       
saccharomyces pastorianus1 and certain  
forms  of very common fungoid growths1  
those of dematium1 and even of the  most
 common mould1 mucor mucedo or          
racemosus1 when it vegetates  beneath   
the surface of a liquid and acts as a   
ferment4#ajh ,we have  here1 as in these
 cases1 filamentous chains branching    
into other similar  chains1 composed of 
more or less elongated cells1 which at  
length fall  off and germinate exactly  

as the conidia-bearing hyphae of mucor  
do4    ,the arobian ferment of 8high0   
yeast1 in whatever medium we cultivated 
it1 presented no peculiarity1 as far as 
its forms were concerned4 ,it was       
composed of cells of spherical shape1   
like ordinary 8high0 yeast1 and         
germinated in the same way as the       
latter4    ,illustration3 ,fig4 #ea4    
,fig4 #ea represents the revival of this
 arobian ferment4 ,we recognize  here   
the branched mode of budding and        
spherical contour characteristic  of    
8high0 yeast proper4 ,nor does the      
arobian ferment of 8low0 yeast  present 
any special peculiarities1 in forms1    
dimensions1 and mode of  growth closely 
resembling the 8low0 yeast from which it
 is derived4 ,at  the commencement of   
its restoration1 however1 if this is    
performed in  sweetened water1 the cells
 in the groups are larger than those    
which are  subsequently developed4      
,illustration3 ,fig4 #eb4    ,fig4 #eb  
represents the arobian ferment of yeast 

used in  8low0-fermentation breweries1  
examined forty-eight hours after        
pitching4  ,we find that groups         
resembling that at a are of very rare   
occurrence4  ,they are to be seen only  
at the very beginning1 generally only   
for the  first few hours of the renewed 
activity4 ,very soon1 however1 they     
develop cells which are of the size of  
the oval cells budding at b4            
,illustration3 ,fig4 #ec4    ,fig4 #ec  
represents the arobian caseous yeast    
which forms rather  rapidly1 in thick1  
greasy-looking pellicles1 on the surface
 of liquids  which have been fermented  
by means of caseous ferment4 ,the larger
 form  of cells1 a and b1 is not often  
met with4    ,illustration3 ,fig4 #ed4  
,on ,may #bgth1 #ahge1 we sowed1 in a   
flask of wort1 a trace of a pellicle  of
 this kind1 which had formed on the     
surface of a flask in which             
fermentation had been set up by means of
 caseous yeast in ,may of the  preceding
 year4 ,on ,may #cjth fermentation began

 to reveal its presence by  a voluminous
 froth1 and the newly-formed yeast had  
reached the bottom of  the flask4 ,a    
small quantity was taken out by a       
capillary glass tube1 and  a sketch of  
the ferment made2 this is given in ,fig4
 #ed4 ,amongst the  cells which occupy  
the field there are groups of some of   
larger size4  ,these are not distinct   
forms mixed with the others1 but simply 
another  illustration of the fact that  
old cells in course of revival1         
especially  when they have been         
exhausted in sweetened water1 as we have
 just  observed of the arobian ferment  
of 8low0 yeast1 commence with forms of  
larger diameter or more elongated than  
the ordinary forms peculiar to  the     
ferment which at a later stage are      
developed from them4 ,we have seen  how 
marked and exaggerated this feature was 
in the case of  saccharomyces           
pastorianus4    ,let us again call      
attention to the forms of arobian       
ferment furnished  by the yeast which we

 have already described under the name  
of new  8high0 yeast4 ,fig4 #ee         
represents this arobian ferment1 as     
taken on  ,november #bgth1 #ahgc1 from a
 pellicle of rather greasy and moist    
appearance1 on the surface of a flask of
 fermented beer-wort which had  been    
impregnated on ,july #bast1 #ahgb4 ,it  
might readily be mistaken for  ordinary 
8high0 yeast1 yet no two ferments can be
 more distinct4    ,illustration3 ,fig4 
#ee4    ,illustration3 ,fig4 #ef4    ,on
 ,november #bgth1 #ahgc1 we sowed a     
trace of this ferment in a flask of     
wort4 ,from the #bith1 with a continuous
 temperature of #be ,c4 7#gg ,f471 a    
considerable deposit of yeast began to  
form1 and the froth of  fermentation    
covered the whole surface of the liquid4
 ,we took a little  of this deposit for 
examination2 it is represented in ,fig4 
#ef4 ,the field  is occupied with oval  
cells of great uniformity4 ,we recognize
 the aspect  of the original yeast      
7,fig4 #dc74 ,here and there1 indeed1 we

 come across  some cells of larger size1
 such as those at a and b1 which is     
another illustration of the remark that 
we have just made respecting the  forms 
which revived exhausted cells take on at
 the commencement of a new  germination4
    ,the physical aspect of the several 
arobian ferments is in general so       
characteristic that we are often able by
 simple inspection to  distinguish      
between them as they occur on the       
surface of liquids4  ,saccharomyces     
pastorianus in its arobian state forms a
 crown of cells  round the sides of the 
vessel at the surface of the liquid1    
which crown  is broken up by the least  
agitation of the liquid2 its vitality   
continues for years4    ,the arobian    
ferment of 8high0 yeast appears in the  
form of small  isolated teats on the    
surface of the fermented liquid4 ,it    
develops  rather sluggishly1 and has no 
great vitality4    ,the arobian form of 
8low0 yeast develops as a somewhat      
fragile layer1  the least agitation     

precipitating it to the bottom of the   
vessel in a  cloud of very small        
irregular flocks1 that do not diffuse   
through the  liquid as they fall4 ,with 
free access to air it retains life for a
 long  time4    ,the arobian ferment of 
caseous yeast forms a continuous        
greasy-looking  pellicle1 gradually     
thickening1 which breaks up into        
fragments when  shaken4 ,with a supply  
of air it lives very long1 and the      
pellicle  gradually increases in        
thickness4    ,in reviewing these       
ferments we may naturally ask ourselves 
the question  whether the 8high0        
ferments of which we have spoken--the   
industrial one  concerned in the 8high0 
fermentation of breweries1 and the other
 which  we have termed new 8high0       
ferment--are not arobian ferments of    
8low0  yeasts4 ,we are inclined to think
 that the ferment which in the preceding
  paragraph we termed new 8high0        
ferment1 may1 perhaps1 be the arobian   
form of the 8low0 yeast employed by     

,alsatian and ,german brewers4 ,we have 
studied this new 8high0 ferment side by 
side with the arobian ferment  of 8low0 
yeast1 and the result we have arrived at
 is1 that in appearance  and mode of    
germination1 as well as in the flavour  
and quality of the  beers which they    
produce1 they greatly resemble one      
another4 ,in the last  respect1 however1
 we cannot say that the identity is     
quite absolute1 and  hence it is with   
some doubt that we suggest the possible 
identity of the  two ferments4 ,as      
regards the ordinary 8high0 yeast of    
breweries1 it may  well be supposed1    
both from its power of rising to the    
surface during  fermentation and from   
the peculiar smell and flavour of its   
beer1 that  we have in it the arobian   
ferment of some 8low0 yeast1 as to the  
identity of which1 however1 we can say  
nothing1 having no knowledge as  to     
where it is to be found2 or1 indeed1 any
 certainty that such a yeast  actually  
exists4    ,in writing these lines an   

idea suggests itself which might be     
profitably  made the subject of serious 
experimental study4 ,what would be the  
peculiar properties of the arobious     
ferment-form of an arobian yeast8       
,certain facts incline us to believe    
that these forms differ from each  other
 just as a 8low0 yeast differs from its 
arobian ferment4 ,if this  were actually
 the case it would be very interesting  
to compare the  peculiar properties of  
an indefinite series of arobian         
ferments1 all  derived from a common    
origin4 ,we find recorded in our        
laboratory notes  that a certain arobian
 ferment of the second generation       
produced a beer  different from that    
produced by the same ferment of the     
first  generation1 being possessed of a 
fragrance so marked that1 on entering   
our laboratory1 in which only a few     
litres of this beer were fermenting1  we
 were at once struck by the powerful    
odour which it emitted4                 
,,vi4--,the ,purification of ,commercial

 ,yeasts4      ,we have already stated  
that the researches detailed in the     
preceding  chapter require for their    
successful prosecution that the ferments
 on  which we experiment should be      
absolutely free from germs of other     
organisms1 and we have shown how        
impossible it would be1 if this         
condition were not complied with1 to    
follow for weeks or months1  sometimes  
even years1 the changes which occur in a
 yeast maintained in  contact with air1 
either in sweetened water or in a liquid
 which has  fermented under its         
influence4 ,equally necessary is it that
 the  saccharine worts employed should  
also be exempt from these impurities1   
as well as the air1 which is being      
constantly renewed at the surface of    
the liquids4 ,these last conditions may 
be realized by the adoption of  our     
double-necked flasks1 with which a      
laboratory for research of this  kind   
should be furnished1 always ready for   
use1 filled with the  different kinds of

 liquids that may be required4    ,in   
general1 the inconveniences resulting   
from the impurity of a yeast  employed  
do not immediately manifest themselves1 
in consequence of the  enormous         
preponderance of the true yeast1 which1 
in comparison with the  foreign germs   
that contaminate it1 may be so great    
that microscopical  examination fails to
 reveal even the presence of these      
latter4 ,again1 it  is a well-known fact
 that the abundance of one growth in a  
limited  medium operates to the         
prejudice of a less abundant one1       
inasmuch as the  first consumes the     
nutritive materials at the expense of   
the second1 and  more particularly the  
needful amount of oxygen4 ,it follows1  
that when a  saccharine liquid is       
impregnated with commercial yeast1      
nothing but  yeast may be detected for a
 time1 and one is led to believe in the 
purity of the subsequent growth4 ,this1 
however1 supposes that the  external    
conditions1 as well as those of the     

medium of growth1 are  equally adapted  
to the life of the yeast and that of    
those organisms  present as impurities2 
for if these conditions rather favoured 
the  nutrition of the latter1 we should 
be sure to find their proper            
developments appearing at an early      
stage4 ,for example1 when the growth  of
 yeast becomes sluggish1 we have        
invariably the development of such      
after-growths4 ,the principal germs1    
having exhausted the saccharine  liquid 
which has fermented under their         
influence and is no longer  adapted for 
their growth1 cease to develop1 and have
 their place taken  by ferments of      
disease1 spores of moulds1 mycodermata1 
c41 the growth  of which proceeds more  
or less rapidly1 in proportion as the   
character  of the liquid and the        
surrounding temperature are more or less
 suited to  their growth4    ,here1 too1
 we have an explanation of the rapid    
change that occurs in  brewers' yeast   
when left to itself after fermentation4 

,in such a mass of  cells1 kept apart   
from any food-supply1 and only with     
difficulty able to  keep themselves in  
life by consuming their own soluble     
contents1 we have  an excellent field   
for the development of foreign germs4   
,in this way we  may have a rapid       
putrefaction in yeast1 to which there   
will be a  correspondingly rapid growth 
of organisms in the liquid1 where they  
find1 as well as in the yeast-cells1    
appropriate nourishment4 ,nothing  could
 better confirm this view of the matter 
than the array of facts1 by  way of     
antithesis1 already described1 in which 
we have seen a pure yeast  remain for an
 indefinite time in contact with pure   
air1 without  undergoing any            
putrefaction1 or manifesting other      
changes than those  which result from   
the combustions peculiar to living cells
 when left to  support themselves1 in a 
moist state1 in contact with oxygen4    
,in the process of brewing1 as soon as  
fermentation is finished1 or  rather1 as

 soon as certain physical effects are   
produced1 for instance1  when the beer  
falls bright1 or1 as the ,french say    
technically1 when the  yeast breaks     
up1#aji the beer is racked2 subsequently
 the yeast1 which  is left in a plastic 
layer at the bottom of the vessels1 is  
collected1  washed1 and kept under water
 in a cool place1 to be used again in   
the  course of twenty-four or           
forty-eight hours4 ,brewers never care  
to keep  their yeast for a longer time  
before using it1 especially in summer4  
,we  can understand how this practice   
prevents the foreign germs which are    
mixed with the yeast from living and    
reproducing2 but although the           
conditions of brewing1 as far as the    
treatment of the yeast is  concerned1   
may1 in a certain measure1 prevent the  
development of these  germs of disease1 
nevertheless they are there1 and from   
their extreme  minuteness1 pass into the
 beer in greater or less number1 however
 bright  it may have been rendered by   

racking4 ,there they only await         
conditions  favourable to their         
existence to enable them to develop1 and
 to affect  more or less injuriously the
 qualities of that delicate beverage4   
,on ,december #aeth1 #ahgb1 we bought   
nine samples of beer in different  large
 cafs in ,paris1 which had all come from
 the best breweries of  ,strasburg1     
,nancy1 ,vienna1 and ,burton4 ,after    
leaving them for twenty-four  hours1 we 
decanted all our samples1 and then sowed
 a drop of the deposit  of each in      
flasks of pure wort4 ,on ,january #bnd1 
#ahgc1 we examined the  ferments formed 
in these worts1 which had been kept in  
an oven at a  temperature of #bj ,c4    
7#fh ,f471 and also tasted the beers    
produced2 they  all had an abominable   
taste1 and each contained diseased      
ferments4    ,at the same time1 by way  
of comparison1 we impregnated other     
flasks of  wort with pure ferments4     
,none of the beers of this series       
acquired a bad  taste or produced       

foreign ferments2 they only became flat4
    ,when we review the operations of   
the brewer's art1 we are surprised by   
the comparative perfection to which that
 art has been brought by the  laborious 
experience of years1 and the more so    
when we consider that1 as  regards the  
question of the diseases of beer1 the   
brewer has never been  guided by any    
such rigorous principles as those which 
we have explained  in this work4 ,we    
have already given proofs of this in our
 first chapter4    ,the beer is racked  
and separated from its yeast before     
fermentation has  entirely ceased4 ,the 
principal reason for this is that it is 
necessary  that the beer1 after being   
run into cask1 should work again and    
undergo  a secondary fermentation1 in   
order that it may not be invaded by the 
parasites1 of which we have already     
spoken1 as would not fail to be the     
case if the beer were suffered to remain
 in a state of perfect  quiescence4 ,not
 only is the beer racked before it has  

attained its limit  of attenuation1 but 
in addition to this1 and also with the  
view of  checking the development of    
parasites1 it is placed in cellars      
sensibly  cooler than the temperature of
 fermentation1 low as that is in the    
case  of 8low0 beers3 the temperature of
 the cellars being not higher than #b   
or #c ,c4 7#cf ,f474    ,unfortunately1 
the requirements of trade prevent our   
complying with  these exigencies to the 
end4 ,when the beer is sold it is       
conveyed away1  no matter what the      
season may be1 and deposited in the     
retailer's  cellar1 for a longer or     
shorter time1 according to the          
variations of  consumption4 ,on a warm  
day beer will be in great demand2 the   
next day1  if rain or cold have come on1
 the demand will be very limited1 since 
beer is1 in our climate at least1 a     
drink for hot weather4 ,from causes  of 
this nature1 the beer may have to remain
 a long time in the cellars  of the     
retailers or consumers4 ,by way of      

precaution1 indeed1 it is put  into very
 small casks1 which permit of a frequent
 renewal of the supply1  and is conveyed
 to distances by express trains1 and    
during the night2 it  is even sent away 
in wagons provided with a kind of double
 case1 the  outer jacket being filled   
with ice1 which keeps the air           
surrounding the  casks constantly cold4 
,such are some of the troublesome       
measures taken  to obviate the danger   
that we have pointed out4 ,they operate 
very  injuriously in restricting the    
trade and raising the price of beer4 ,it
  is a matter of extreme importance1    
then1 that our produce should be  better
 removed from the action of those       
microscopic enemies which beer          
contains2 in other words1 that this     
beverage should have less cause to  fear
 circumstances favourable to the        
development of the germs of  impurity   
with which it is always contaminated1 as
 a natural consequence  of the methods  
of manufacture at present adopted4 ,the 

question of  alteration in the flavour  
of beer should be regarded from another 
point  of view which merits equal       
attention4 ,we have seen that there are 
different kinds of beer1 each of which  
corresponds to a special ferment  from  
which it derives its flavour and aroma1 
and1 in a word1 everything  which gives 
it a value in the eyes of the consumer4 
,it very often  happens1 especially in  
badly-managed breweries1 and more       
particularly in  those in which several 
beers are manufactured1 that the yeast  
is a  mixture of different ferments4    
,the evil effects of such a mixture are 
experienced in the course of            
manufacture1 and still more so in the   
beer  after manufacture4 ,brewers in    
good 8low0 fermentation breweries1 who  
brew what is called stock beer1 during  
the winter months1 for  consumption in  
summer1 up to ,august and ,september1   
are very anxious to  prevent the        
development of a vinous flavour in beers
 of this kind4  ,according to our       

observations1 this vinous flavour seems 
to be  principally due to an            
intermixture with the pitching yeast of 
saccharomyces pastorianus or its        
varieties1 one of the peculiarities  of 
which ferment is that in the course of  
time it imparts a decided  vinous       
flavour to beer4 ,if this ferment were  
not present amongst the                 
yeast-cells--and here we are speaking of
 an absolute1 so to say1  mathematically
 absolute absence--the beer produced    
would gradually grow  old in the store  
cellars1 without ever acquiring any     
vinous flavour1  properly so called4    
,this vinous flavour develops more      
especially in ,english beers when these 
are kept4 ,it is an easy matter to show 
that in ,english beers1 after  their    
manufacture1 saccharomyces pastorianus  
and the ferment which we  have termed   
caseous1 which also imparts a peculiar  
flavour1 form  almost exclusively1      
notwithstanding the fact that the yeast 
used in the  manufacture of ,english    

beer is a ferment essentially distinct  
from  saccharomyces pastorianus4    ,the
 secondary fermentation which takes     
place in 8high0 and 8low0 beers  stored 
in cask after manufacture1 is very often
 due to this same  ferment1 which may be
 recognized by elongated jointed cells1 
at times  more or less ramified1 as well
 as by the influence which it exercises 
upon the flavour of the beer4    ,we may
 add that the general result of our     
researches has convinced us  that 8high0
 yeast cannot transform itself1 any more
 than 8low0 yeast  can1 into the ferment
 of which we are speaking1 and that     
whenever a beer  produced by means of   
8high0 or 8low0 yeast develops a foreign
 ferment1  this ferment must have       
existed in the original yeast in the    
form of  germs1 which1 from their       
extreme scarcity1 often fail to be      
detected by  means of the microscope4   
,the best proof that we can give of this
 is the  fact that a beer produced by   
means of 8high0 or 8low0 yeast1 if left 

to  itself for months or years1 will    
never contain in its deposit anything   
besides the yeast that was used in its  
manufacture1 provided that that  was    
pure to begin with4 ,now this can never 
be the case in dealing with  actual     
commercial beers1 no matter what they   
may be or in what brewery  they may be  
produced4 ,in all beers1 in the course  
of time1 in addition  to diseased       
ferments1 ferments essentially different
 from those used in  their manufacture  
will appear1 and notably saccharomyces  
pastorianus2  this result must be       
attributed to the general impurity of   
commercial  yeasts4    ,in certain cases
 the intermixture of ferments is to be  
feared almost as  much as the presence  
of diseased ferments1 when these latter 
have not  developed to any great extent4
 ,we have often seen our fermentations  
invaded by ferments differing absolutely
 from those which we originally         
employed4 ,the repetition of growths1   
and more particularly changes in  the   

composition of our fermentable media1   
purposely made with the view  of        
attaining certain results1 often produce
 complications of this kind4  ,for a    
long time we were unable to realize the 
true significance of the  results of    
some of our experiments1 in consequence 
of the facts which we  have just        
explained1 as well as those detailed in 
the preceding  paragraph1 having escaped
 our notice2 indeed1 our ignorance of   
those  facts added greatly to the       
difficulty and length of our researches4
 ,our  labours from the commencement of 
this work to the date of its            
publication have extended over not less 
than five years1 and no one can  know   
better than ourselves with what         
advantage we might devote a still       
longer time to it2 but1 as ,lavoisier   
says1 one would never give anything  to 
the world if he delayed doing so until  
he fully attained unto his  ideal aims1 
which always seem more distant the more 
one increases one's  efforts in the     

attempt4    ,our preceding observations 
show how extremely important it is to   
employ  pure yeasts to obtain1 on the   
one hand1 well flavoured beers1 whilst  
adhering to the processes at present    
existing in breweries1 and on the       
other1 beers of good keeping qualities1 
less liable to injury1 less  dependent  
on actual commercial requirements1      
capable1 that is1 of  withstanding      
conditions favourable to the development
 of ferments  prejudicial to the        
soundness of the produce1 what we have  
named ferments  of disease4    ,in the  
case of intermixture of alcoholic       
ferments1 we may sometimes  manage to   
effect their separation by taking       
advantage of their unequal  vitalities  
in different media of cultivation4 ,on  
,december #agth1 #ahgb1 we  made a      
powder of commercial ,dutch yeast and   
plaster1 as described in  ,chapter      
,,iii4  #f4 ,the ,dutch yeast was a     
8high0 ferment4    ,on ,july #beth1     
#ahgc1 we sowed a portion of this dried 

mixture in a flask  of pure wort4 ,from 
,july #bgth patches of bubbles from     
fermentation were  visible on the       
surface4    ,on ,august #bnd the        
fermentation was completed4 ,the yeast1 
examined under  the microscope1 was     
apparently pure1 formed of spherical    
cells of a  fine 8high0 ferment4 ,we    
poured away the fermented liquid1       
observing  every necessary precaution1  
and left in the flask almost all the    
deposit  of yeast1 and not more than one
 or two cubic centimetres 7about half a 
tea-spoonful7 of beer4    ,on ,november 
#aeth following the yeast1 examined     
afresh1 still seemed pure  and still    
exhibited the form of round cells of    
8high0 yeast1 only that  they had taken 
on a very aged aspect1 showing a double 
contour1 and  filled with granulations  
collected irregularly about the centre4 
,such  are the precise characteristics  
of dead cells2 nevertheless it was still
  possible that some living cells yet   
remained4 ,to assure ourselves of  this 

we took some of the yeast and placed it 
in a flask of pure wort4 ,on  the #aith 
a little froth from fermentative action 
appeared on the  surface4 ,we then      
examined the yeast and discovered that  
it was no longer  8high0 yeast1 but a   
small ferment of rather irregular       
appearance1 in  which the jointed cells 
of saccharomyces pastorianus1 as it     
usually  appears after a succession of  
growths1 predominated4 ,it must not be  
imagined here that what we saw was a    
transformation of one yeast into        
another4 ,the phenomena are to be       
explained much more simply4 ,the ,dutch 
yeast employed being very impure must   
have contained traces of foreign        
ferments1 especially of saccharomyces   
pastorianus4 ,reduced to a dry  powder  
on ,december #agth1 #ahgb1 the two or   
more varieties of cells  comprising it  
had preserved their vitality in         
consequence of the  plaster1 and this   
vitality had continued at all events    
until ,july #beth1  #ahgc4              

,subsequently1 when cultivated in wort1 
they had multiplied in that  medium4    
,the saccharomyces had revived like the 
rest1 but its quantity1  compared with  
the high ,dutch yeast1 was so small that
 the microscopical  observations made on
 ,august #bnd1 when the flask was       
decanted1 failed to  discover its       
presence4 ,between ,august #bnd and     
,november #aeth the high  yeast must    
have perished entirely3 the cells of    
saccharomyces1 on the  contrary1 still  
maintained their vitality1 and these    
alone multiplied in  the flask of wort  
impregnated on ,november #aeth4 ,here we
 have an example  of the separation of  
alcoholic ferments1 through the unequal 
resistance  they sometimes offer to     
adverse conditions to which they may be 
subjected4 ,we may also conclude that if
 we had prepared a quantity of  beer    
with the 8high0 yeast1 which in our     
experiment of ,august #bnd1 #ahgc1      
seemed to have developed in a state of  
entire purity1 this beer when  made and 

stored in cask or bottle could not have 
failed to undergo a  secondary          
fermentation1 in consequence of a       
development of  saccharomyces           
pastorianus4    ,let us take1 as another
 example of purification of the same    
kind1 the  case of the different        
ferments of the vintage4 ,when must     
begins to  ferment the apiculated       
ferment invariably appears1 and becomes 
afterwards associated1 more or less1    
with the saccharomyces  pastorianus1 in 
the presence of which the multiplication
 of the  apiculated ferment soon ceases4
 ,saccharomyces pastorianus1 in its     
turn1 is gradually displaced by the     
ferment which we have termed the        
ordinary ferment of wine1 and which ,dr4
 ,rees has named saccharomyces          
ellipsodeus4 ,on the subject of these   
changes in the proportion of the        
ferments of wine1 the ,note which we    
published in #ahfb in the ,bulletin  de 
la ,socit chimique may be consulted4    
,now1 these various ferments  mutually  

interfere with each other3 whereas if   
saccharomyces  apiculatus were there    
alone it would multiply to a greater    
extent1 and  with greater advantage to  
the fermentation of the must4 ,this     
result is  obtained by filtering the    
must1 as we have already observed4      
,it is evident from what we have just   
said that the principal part of the     
deposits of yeast in the sediment of    
fermented grapes1 at the time when  the 
wine is first racked1 which in the      
,jura1 is called l'entonnaison1  is     
composed of the ordinary ferment of     
wine1 the saccharomyces  ellipsodeus1   
and that the cells of apiculated ferment
 are scarcely  discoverable with the    
microscope1 being scattered amongst an  
infinite  multitude of other            
ferments4#aaj    ,illustration3 ,fig4   
#eg4    ,we procured from ,arbois1 on   
,january #bjth1 #ahge1 some wine yeast  
taken  from a large barrel of the       
preceding vintage1 racked on ,january   
#ahth4  ,the ferment was very irregular4

 ,some of its cells were very old1 of a 
yellowish colour1 and full of           
granulations--amongst these a certain   
number formed jointed segments1 rather  
elongated1 and probably belonging  to   
saccharomyces pastorianus4 ,the other   
cells were transparent1 and  apparently 
still young4 ,this mixture of the two   
ferments is represented  in ,fig4 #eg4  
,no doubt if we had searched carefully  
we should also have  found some cells of
 saccharomyces apiculatus4 ,on ,january 
#bast we sowed  a small quantity of this
 raw yeast in a flask of sweetened      
water4 ,on the  #bdth we poured off the 
liquid1 and supplied the deposit with   
fresh  sweetened water4 ,the exterior   
temperature was #ab ,c4 7#ed ,f474 ,on  
the  #bgth we took some of the deposit  
and put it into a flask of wort4 ,the   
following days there was a development  
of yeast1 accompanied by  fermentation4 
,we obtained1 however1 neither the large
 forms of the  ferments of fruits1 nor  
those of the more minute ferments       

represented in  ,plate ,,xi4 ,the       
saccharomyces pastorianus1 represented  
in the yeast  which we sowed by aged1   
granular1 elongated cells1 had1         
therefore1 not  revived4 ,fearing that  
this result might have been attributable
 to  insufficiency of the exhaustion1   
which had only lasted for a few days1   
we raised the temperature of the flask  
of sweetened water to #be ,c4 7#gg      
,f471 at which we kept it until         
,february #bjth4 ,on that day we sowed  
some  of this yeast in wort4 ,there was 
a very perceptible revival the next     
day1 but it was still impossible to     
detect with the microscope the forms  we
 have just mentioned1 nor did           
saccharomyces pastorianus appear in     
fresh1 succeeding growths4              
,illustration3 ,fig4 #eh4    ,fig4 #eh  
represents the yeast formed1 which      
evidently had sprung from the           
transparent cells seen in ,fig4 #eg1 and
 doubtless belonging to the  ordinary   
ferment of wine1 saccharomyces          

ellipsodeus4 ,here we have  another     
example of the natural separation of    
ferments brought about by  the death of 
one or two of them1 or by extreme       
differences in the time  of their       
revival4    ,we cultivated this yeast   
7,fig4 #eh71 to some considerable       
extent1 in  beer-wort4 ,it produced a   
peculiar beer1 of vinous character1 in  
fact a  true barley wine4 ,this proves1 
we may here remark1 that ordinary wine1 
in its flavour and quality1 depends to a
 great extent on the specific  nature of
 the ferments which develop during the  
fermentation of the  vintage2 and we may
 fairly assume that if we were to       
subject the same  must to the action of 
different ferments we should obtain     
wines of  different characters4 ,with a 
view to the practical application of    
this  idea1 it would be well to         
undertake new studies in this direction2
 and  the methods of cultivating and    
managing ferments1 explained in this    
work1 would be of great value in such   

researches4    ,the purification of     
ferments may be accomplished by various 
methods1  according as we have to deal  
with an intermixture of ferments1 or to 
regard as our principal object the      
expulsion of ferments of disease1  such 
as vibrio germs1 lactic ferment1 the    
filamentous ferment of turned  beer1    
mycoderma aceti or mycoderma vini4      
,one method of easy application consists
 in sowing the yeast in water  sweetened
 with #aj per cent4 of sugar4 ,this     
liquid should be first  boiled1 and     
preserved in the two-necked flasks which
 we have so often  described4 ,sweetened
 water is a very exhaustive medium for  
ferments1 and  the organisms mixed with 
them4 ,a great many cells perish in it1 
and the  chances are that the foreign   
germs1 which are always scarce in       
comparison with the great number of     
cells of ferment1 may be amongst  those 
which die1 or those which become so     
exhausted that when the yeast1  after   
this treatment1 is sown in wort1 they   

disappear1 and allow those  cells which 
have remained vigorous enough to develop
 alone4 ,the addition  of a little      
tartaric acid to the saccharine         
solution--say1 from #a_/ajjj to         
#b_/ajjj part by weight--often          
facilitates the destruction of certain  
germs  of impurity4 ,mycoderma aceti and
 mycoderma vini do not find suitable    
life-conditions in the sweetened water2 
they soon disappear if  cultivated      
alternately in sweetened water and wort4
    ,in the place of flasks we may make 
use simply of shallow basins1 covered   
with sheets of glass1 such as we have   
already had occasion to describe1  for  
cultivating yeast in wort after it has  
been for a longer or shorter  time in   
the sweetened water4 ,the success of    
these methods of  purification is mainly
 due to the fact that wort is highly    
aerated1 and  experience shows that the 
principal disease-ferments of beer are  
as much  checked in their development by
 the presence of air as they are        

favoured  by its absence1 the inverse of
 which holds good in the case of        
alcoholic  ferments4 ,so true is this   
that1 working with commercial yeast1    
which is  invariably impure1 it would be
 impossible in our opinion to make beer 
in  closed vessels2 and1 indeed1 as a   
matter of fact1 one has never  succeeded
 in doing this1 although the attempt has
 often been made4 ,to do  so requires1  
much more than in methods actually in   
use1 the employment  of pure yeast4     
,there is1 therefore1 this advantage in 
cultivating yeasts in shallow  basins1  
that the multiplication of the alcoholic
 ferments is promoted1  and that of most
 of the disease-ferments is checked4    
,there is an  exception1 indeed1 in the 
case of mycodermata2 but of all         
disease-ferments these are the most     
easily got rid of1 by repeating our     
growths before they make their          
appearance4 ,notwithstanding this1 our  
two-necked flasks1 which also contain   
much air at first1 are to be  preferred 

to the shallow basins1 inasmuch as they 
are a perfect  safeguard against the    
germs floating in the surrounding air1  
as well as  those of the ferment        
saccharomyces pastorianus4    ,another  
method is suggested to us by the curious
 results of which we  have already      
spoken1 obtained by sowing yeasts in a  
wort rendered acid  and alcoholic by the
 addition of bi-tartrate of potash and  
alcohol4  ,experience proves that many  
disease-ferments find great difficulty  
in  withstanding a succession of growths
 in wort to which #a- per cent4 of      
tartaric acid and from #b to #c per     
cent4 of alcohol have been added4 ,such 
a mixture1 however1 is equally well     
adapted to the requirements of          
saccharomyces pastorianus1 and we must  
always assure ourselves that  this      
organism has not taken the place of the 
yeast we are endeavouring  to purify4   
,growths at a very low temperature are  
of great help in  enabling us to get rid
 of all ferments that are foreign to    

8low0 yeast1  and should be resorted to 
in all cases where this yeast is to be  
purified4    ,another method of         
purification1 which is perhaps quicker1 
although  inferior in other respects1   
consists in the employment of carbolic  
acid--that is to say1 in purifying our  
yeast by successive growths1 we  may add
 to every #ajj c4c4 7#c- fluid ounces7  
of wort that we employ from  ten to     
twelve drops of phenol water1 containing
 #aj per cent4 of the  acid4 ,the action
 of the phenol1 which at first is       
invariably combined  with that of the   
oxygen of the air1 tends to destroy the 
vitality of  many of the cells sown1    
involving to some extent also the yeast 
which we  are interested in preserving4 
,but amongst the number of cells that   
are  affected those which are less      
abundant1 that is to say1 those which   
are  present as impurities1 are         
paralyzed relatively in much greater    
proportion4 ,if the acid does not       
destroy them it greatly checks their    

development1 and the cells of yeast1    
which multiply continuously in vast     
numbers 7for the fermentation goes on in
 spite of the phenol1 if this is  added 
in small quantity71 gradually choke the 
foreign germs in a  succession of       
growths4    ,by these different means1  
which are employed separately or        
combined with  one another1 we generally
 manage to obtain the yeast which we    
wish to  purify in a very pure state4   
,we need scarcely add that it is always 
well1 in the case of our purifications1 
to begin with specimens which  are      
already as pure as it is possible to    
obtain them4 ,in making our  choice the 
microscope is our best guide1 but it is 
not a sufficient one4  ,we should be    
strangely deceived if we believed in the
 purity of a yeast  for the sole reason 
that when examined under the microscope 
it appeared  to contain nothing of a    
foreign nature4 ,the best means of      
assuring  ourselves of the purity of a  
yeast consists in making some beer in   

one  of our two-necked flasks1 and      
leaving this flask1 after fermentation1 
in  an oven at a temperature of #bj or  
#be ,c4 7#fh to #gg ,f474 ,if the beer1 
in the course of a few weeks1 does not  
thicken1 or become covered with         
efflorescence1 if its deposit is        
microscopically pure1 if1 in short1 it  
only tastes flat1 we may have every     
confidence in the purity of the  yeast  
which produced it4 ,after we have       
purified a yeast we are1  unfortunately1
 never sure that it has not undergone   
some change in the  course of the       
manipulations to which it has been      
subjected in  purification4 ,it is      
indispensable1 therefore1 that we should
 test it1  and see if the flavour of the
 beer produced by it is really the one  
that  we want--viz41 that of the beer   
from which we took the yeast that we    
submitted to purification4    ,in the   
course of a series of practical         
experiments that we were carrying  out  
in the large brewery of ,tourtel1 at    

,tantonville1 in #ahge1 in  connection  
with the new process of brewing1 which  
will be explained in  ,chap4 ,,vii41 the
 following circumstance occurred4 ,we   
had purified some of  the yeast of the  
brewery1 by means of a succession of    
growths and adding  a few drops of      
phenol1 and had obtained a yeast of     
irreproachable  purity4 ,it happened    
that this yeast1 which was repeatedly   
cultivated in  the brewery during the   
summer of #ahge1 from six to ten        
hectolitres 7#acj  to #bbj gallons7 of  
wort being used on each occasion1 always
 produced a  beer that had a            
yeast-bitten flavour and defective      
clarifying powers1  notwithstanding that
 it possessed remarkable keeping        
properties1 which  it owed to the       
pureness of the ferment employed4 ,as a 
matter of fact1  the beer suffered no   
injury from journeys of more than #cjj  
miles1 by  slow trains1 in ordinary     
casks1 containing from #ej to #ajj      
litres 7#aj to  #bj gallons71 during the

 great heats of ,june and ,july1 or from
 being  subsequently stored for two     
months in a cellar1 the temperature of  
which  rose during that time from #ab to
 #ah ,c4 7#ed to #fe ,f474 ,the         
temperature of fermentation had been #ac
 ,c4 7#ee ,f474 ,beer from the same     
brewery1 made with the same wort by the 
ordinary process1 did not remain  sound 
for three weeks in this same cellar4    
,to what may we attribute the           
peculiarity of the beer as just         
described8  ,it is probable that during 
our processes of purification some      
ferment  had taken the place of the     
principal yeast4 ,commercial yeasts1    
even  those with which the brewer is    
thoroughly satisfied1 generally contain 
various ferments1 which are maintained  
in their relative proportions1 or  very 
nearly so1 by the uniform conditions    
under which work is carried on  in a    
brewery2 but these proportions1 it is   
obvious1 might be very  seriously       
affected by any radical change in the   

conditions of growth4    ,footnote #hb3 
,extract from a ,note which ,i inserted 
in #ahfb in the ,bulletin de la         
,socit chimique of ,paris4    ,footnote 
#hc3      ,schtzenberger1 in his work on
 8,fermentation10 following ,dr4 de     
,vaural4 ,paris1 #ahge1 p4 #bgh4 ,see   
pp4 #fa1 #fb ,english version in        
,international ,scientific ,series 7,h4 
,s4 ,king  ,co41 ,london1 #ahgf74 ,this 
appears to be the only reference to this
 subject in the ,english    copy4--,d4  
,c4 ,r4    ,footnote #hd3      ,the     
principal result of ,dr4 ,rees' labours 
consists in the discovery of    a       
sporulation peculiar to yeast cells1    
that is to say1 to a formation    in the
 interior of these cells1 and under     
particular conditions--such    as when  
the growth occurs on slices of cooked   
potatoes1 carrots1    c4--of two1 three1
 or four smaller cells1 which1 when     
placed in    fermentable liquids1 act   
like the germinating spores of ferments4
 ,the    mother-cell may be regarded as 

an ascus1 and the daughter-cells as     
ascospores1 and so the genus            
saccharomyces may be classified among   
the group of fungi termed ascomycetes4  
,these facts have been    frequently    
confirmed1 notably by ,dr4 ,engel1      
professor of the ,faculty    of         
,medicine1 at ,nancy4 ,previously to    
,dr4 ,rees' discovery1 ,m4 de ,seynes   
7,comptes rendus1 t4 lxvii41 #ahfh7 had 
described an endogenous    formation of 
spores in mycoderma vini1 particularly  
in the elongated    cells1 followed by  
the rupture of the mother-cell1 and     
subsequent    absorption of cell-walls  
and other contents after the issue of   
the    endospores1 which we have just   
termed ascospores4 ,we ourselves had    
also previously called attention to     
those refractive corpuscles which       
appear amongst vibrios as probably being
 reproductive corpuscles1 and    we had 
likewise witnessed the reabsorption of  
the parts surrounding    them4 ,the     
plate on page #bbh of our 8,studies on  

the ,silkworm ,disease0    represents   
the phenomena in question4    ,footnote 
#he3      ,see ,comptes rendus de       
l',acadmie des ,sciences1 vol4 lviii4 p4
 #add4    ,footnote #hf3      ,the      
plates referred to in this paragraph    
were exhibited at a meeting    of the   
,academy of ,sciences1 ,november #ah1   
#ahgb1 and commented upon by    the     
perpetual secretary1 ,m4 ,dumas4        
,footnote #hg3      ,for these          
observations1 we employed small glass   
cells1 which we made    out of some ,st4
 ,gobain glass by punching holes through
 it1 and then    cementing on one side  
one of the little glasses used for      
covering    objects in microscopical    
examinations4 ,in this manner we made   
small    troughs1 in which we placed    
some wort that had been boiled1 and a   
drop    of the water in which grapes had
 been washed4 ,to prevent evaporation   
we covered the cells with a sheet of    
glass4 ,we examined the liquid in       
these cells by inclining our microscope 

to the angle required4#hh               
,illustration3 ,fig4 #bi4      ,we also 
made use of cells similar to those      
employed by ,,mm4 ,van ,tieghem    and  
,lemonnier#hi in their researches on    
mucorines 7,fig4 #cj74                  
,illustration3 ,fig4 #cj4      ,an      
apparatus similar to that employed by   
,m4 ,duclaux in #ahecij would    do     
equally well4 ,we should be able to work
 with even greater facility    if we    
employed bulbs like some which we       
ordered in ,germany1 some    twelve     
years ago1 of the well-known            
glass-blower1 ,geissler4 ,we have       
heard that these bulbs now sold by that 
maker are much used by ,german          
microscopists4 ,they consist of a tube  
blown out into a flat bulb1 the    sides
 of which1 in the centre1 come          
sufficiently close together to          
enclose but a very thin layer of liquid1
 and to admit of microscopical          
examination4 ,we may fill these         
tube-bulbs completely with liquid1 to   

the exclusion of air or we may surround 
the central drop with air4              
,illustration3 ,fig4 #ca4    ,footnote  
#hh3      ,in our essay on acetic       
fermentation1 published in #ahfd1 we    
have    already described this          
apparatus1 which we employed to follow  
the    multiplication of the jointed    
filaments of mycoderma aceti4 ,see      
,,pasteur1 ,etudes sur le vinaigre1 p4  
#fd1 ,paris1 #ahfh4    ,footnote #hi3   
,,van ,,tieghem and ,,lemonnier1        
,annales des ,sciences naturelles1 #eth 
series1 ,botanique1 t4 xvii4 #ahgc4     
,footnote #ij3      ,,duclaux1 ,comptes 
rendus des sances de l',acadmie des     
,sciences1 t4    lvi4 p4 #abbe4         
,footnote #ia3      ,in experiments of  
this kind there is always a slight      
increase in the    volume of air in the 
jar4 ,this increase may be very         
perceptible even    when the experiment 
made with fresh grapes1 in ,august1 for 
instance1    causes no fermentation due 
to the action of yeast4 ,after the      

oxygen of    the air has been absorbed  
and replaced by carbonic acid gas1      
either by    direct oxidation or by the 
action of moulds1 the grapes1 although  
crushed1 act like fruits plunged into   
carbonic acid gas#ib1 and this    effect
 is even more marked in the case of     
imperfectly crushed grapes4    ,the     
reason is1 that the crushing is never so
 perfect as to injure all    the cells  
of the parenchyma4 ,we may easily       
convince ourselves that the             
experiment on the liberation of carbonic
 acid gas and the formation of          
alcohol by grapes and fruits in general 
when plunged into carbonic    acid      
succeeds very well in the case of       
fragments of fruits or grapes1    and   
succeeds better the less the parts are  
crushed4    ,footnote #ib3      ,see    
paragraph3 ,fermentation in saccharine  
fruits immersed in carbonic    acid gas1
 ,chap4 vi1  #b1 p4 #bff4    ,footnote  
#ic3      ,dr4 ,rees has given the name 
saccharomyces ellipsoideus to the       

ferment of wine represented in ,plates  
,,viii4 to ,,xi4 of our 8,studies on    
,wine10 which we have termed the        
ordinary ferment of wine1 from its      
being the most abundant of the ferments 
found at the end of the    fermentation 
that produces the wine4    ,footnote    
#id3      ,the alcoholic ferments in    
general1 subjected to these weakening   
influences1 have not all the same power 
of resistance4 ,that one which    seems 
to possess this power in the highest    
degree is the    saccharomyces          
pastorianus1 which ferment we had in    
view in writing    the above4           
,footnote #ie3      ,the term exhaustion
 7puisement71 which we have just used1  
was1    perhaps1 not altogether         
felicitously chosen4 ,no doubt we       
exhaust the    cells of yeast when we   
sow an imponderable weight of them in a 
large    quantity of sweetened water2 it
 might1 however1 be better to say that  
in such a case we adopt a particular    
method of preserving the vitality    of 

the cells1 without suffering them to die
 of exhaustion1 or to    multiply by    
budding4 ,we may remark that the yeast1 
in this case1    exists in a state of   
latent life1 which resembles that of    
cells on the    surface of fruit4 ,the  
cells on the surface of fruits1 bunches1
 or    barks1 can no more find around   
them sufficient aliment for their       
propagation than can our yeast-cells in 
a great excess of sweetened    water4   
,we would not1 however1 say of the      
spores on the surface of    fruits1 or  
their woods1 that they are in a state of
 exhaustion2 the    term would be       
misapplied4    ,footnote #if3      ,see 
foot note p4 #gi4--;,d4 ,c4 ,r4         
,footnote #ig3      ,m4 ,bchamp         
7,comptes rendus1 ,november #ahth1      
#ahgb7 asserts that the    air has no   
direct influence on the production of   
ferment or on the    process of         
alcoholic fermentation4 ,that           
experienced chemist deduces    this     
erroneous assertion from experiments on 

sweetened water1 to which    bunches of 
grapes1 petals of corn-poppies and      
petals of robinia    pseudo-acacia had  
been added4 ,as may be seen in our      
8,studies on ,wine0    7p4 #g1 #ast     
edition1 #ahff71 these experiments      
conducted by ,m4 ,bchamp    in #ahgb    
were merely a reproduction of those made
 long before with vine    leaves1 petals
 of elder-flowers1 leaves of sorrel1 c41
 by the ,marquis    de ,bullion1        
,fabroni1 and other experimentalists4   
,m4 ,bchamp has    modified his later   
experiments by not adding the bunches of
 grapes1    leaves1 c41 to the sweetened
 water before having introduced carbonic
    acid gas into the liquid4           
,fermentation having still taken place  
in    spite of this change1 ,m4 ,bchamp 
wrongly concluded that air has no       
direct influence on the production of   
yeast on an alcoholic    fermentation4  
,the introduction of the carbonic acid  
gas could not    remove all the air     
imparted to the sweetened water by the  

objects    placed in it1 and it was this
 air which remained adhering to these   
objects that permitted the production of
 fermentation4 ,we may avail            
ourselves of the opportunity here       
presented to add that1 in this same     
,note of ,november1 #ahgb1 ,m4 ,bchamp  
commences by making various             
assertions concerning the forms assumed 
by cells of the alcoholic    ferment of 
the grape when in process of            
fermentation4 ,this question    was     
discussed by us ten years before1 and   
our conclusions supported by            
sketches1 in a ,note which appeared in  
the ,bulletin de la ,socit    chimique  
de ,paris1 for #ahfb4    ,footnote #ih3 
,the germs of ferments are less widely  
diffused than ,m4 de ,bary    supposes1 
as may be seen from our observations in 
,chap4 ,,iii4 ,see1 too1    our ,memoir 
of #ahfb1 ,sur les ,gnrations dites     
,spontanes1 p4 #di4 ,it    is only in a 
laboratory devoted to researches on     
fermentation1 or    places such as      

vaults1 cellars1 and breweries1 that the
 air holds    appreciably in suspension 
cells of ferments1 ready to germinate in
    saccharine media4 ,if we except     
these particular circumstances1 ferment 
is not very largely diffused1 save on   
the surface of fruits and the    wood of
 the trees which bear them1 and perhaps1
 also1 on some other    plants4 ,the    
particles of dust held in suspension in 
any atmosphere    whatever rarely       
produce fermentation in pure must even  
when we take    all possible            
precautions1 so that the action be not  
overlooked2 for    true fermentation may
 be hidden by fungoid growths1 when     
there is much    air and but a small    
quantity of saccharine liquid present4  
,footnote #ii3      ,in these           
experiments the apiculated ferment      
appeared sometimes1 but    much less    
frequently than saccharomyces           
pastorianus4 ,we also met    with the   
ellipsoidal ferment4 ,we should probably
 have a greater    variety of ferments  

if our experiments could be conducted in
 the open    air1 but insects and       
particles of dust of all kinds brought  
by the    wind render experiments under 
such conditions difficult and           
untrustworthy4 ,in a laboratory we have 
not these difficulties to    contend    
against1 but1 unfortunately1 the        
operations ordinarily carried    on     
there cause the results of our          
experiments to be of a less general     
character than they would be if obtained
 in free contact with country    air4   
,footnote #ajj3      ,a rather serious  
clerical error appears to have here     
crept into the    original1 for on      
referring to ,plate ,i4 and the         
letterpress descriptive    of ,no4 #g   
7p4 #e71 we find it applies to a very   
formidable species of    diseased       
ferment1 whereas the author is here     
speaking of an amorphous    deposit1    
harmless in character1 and more or less 
associated with all    yeasts4          
,doubtless ,no4 #g should stand ,no4 #f1

 see p4 #f4--;,d4 ,c4 ,r4    ,footnote  
#aja3      ,we would here call the      
reader's attention to the following     
extract    from ,dr4 ,graham's          
appreciative review of this work in     
8,nature10    ,january #aath1 #ahgg4 ,he
 says3 8,m4 ,pasteur seems to be in     
error in    stating 7p4 #aij1 ,fr4 ed47 
that the bottom yeast may be            
distinguished    by being less spherical
 than top yeast4 ,it is true that in    
,london and    ,edinburgh yeast1 the    
cells will be found usually round2 hard 
water1    however1 such as that at      
,burton1 or artificially made so1 yields
 yeast    in which the cells are        
distinctly ovoid in appearance1         
resembling very    closely ,bavarian    
bottom yeast40--,d4 ,c4 ,r4    ,footnote
 #ajb3      #dc ,f4 to #df ,f4 or #ei   
,f4 to #fh ,f4    ,footnote #ajc3       
,on this point again ,dr4 ,graham       
expresses some dissent 78,nature10 loc4 
cit473 8,here surely ,m4 ,pasteur must  
be thinking rather of the inferior      

products of the surface fermentation in 
,france and ,germany1 than of    those  
of ,england and ,scotland40--,d4 ,c4 ,r4
    ,footnote #ajd3      #bhd c4c4  #a  
fl4 oz4 approximately4    ,footnote     
#aje3      ,m4 ,pasteur has evidently   
employed the word 8caseous0 to express  
the    curdy nature of the ferment he is
 describing1 its plasticity and other   
peculiarities of physical character2 but
 we are1 nevertheless1 tempted    to    
suggest that he may have had in mind    
also the peculiar 8cheesy0    odour     
given off by these very yeasts1 which he
 refers to in the text    as containing 
a considerable intermixture of 8caseous 
ferment40--,f4 ,f4    ,footnote #ajf3   
,the caseous ferment1 however1 must not 
be exposed to heat1 under the           
afore-mentioned conditions1 when it is  
too young4 ,at the commencement    of   
its development1 for instance1 within a 
few days of having been    sown4 ,in    
such case1 it would be in danger of     
perishing1 probably in    consequence of

 the tenderness of its tissues4 ,at the 
end of a    fermentation1 and even      
several months afterwards1 it might be  
safely    heated to #ej ,c4 7#abb       
,fahr47 without any harm to it4 8,low0  
yeast also    can withstand a           
temperature of #ej ,c4 in the medium in 
question4    ,footnote #ajg3            
,although we believe that the arobian   
ferment of a particular yeast    may be 
produced by a kind of transformation of 
the cells of the    latter1 yet we admit
 that this question is open to some     
doubt4 ,the    facts which we           
unexpectedly discovered in connection   
with the    caseous ferment should make 
us extremely careful1 and disposed to   
inquire whether arobian ferments do not 
originally1 in a state of               
intermixture1 form part of the ferments 
from which they spring4 ,one    reason  
which might incline us to believe this1 
is the fact that a    ferment sometimes 
perishes without the appearance of      
arobian ferment    on the surface4      

,there is nothing very natural indeed in
 the hypothesis    that we advance1     
which sets aside the supposed           
intermixture2 but1 on    the other hand1
 if the arobian ferment is a particular 
ferment1    simply intermixed with some 
other variety and developed by change of
    conditions1 how are we to account   
for its great resemblance in            
appearance and mode of budding to the   
ferment on the surface of which    it   
appears8 ,this resemblance1 however1    
might be accounted for very    naturally
 if the two ferments were originally    
related4    ,footnote #ajh3      ,we    
insist on this fact1 that ,fig4 #ej     
represents the forms on revival    of   
the arobian ferment of saccharomyces    
pastorianus1 when this has    grown in a
 mineral medium4 ,when produced on the  
surface of fermented    wort1 the       
arobian ferment of which we are speaking
 presents no    peculiarity1 nor is     
there any irregularity in its forms or  
in its    development1 and when we      

proceed to cultivate it in a natural    
saccharine medium1 or in wort1 it does  
not produce any forms of    dematium1 as
 in the preceding case2 but the reason  
of this is that1    in consequence of   
the nature of the first medium1 which is
 better    adapted to its nutrition1 it 
assumes at once1 in the second medium1  
the forms of deposit-yeast in the course
 of ordinary germination4    ,footnote  
#aji3      8,la cassure de la levre40   
,footnote #aaj3      ,we have reason to 
believe that the ratio of the           
proportions of these    ferments depends
 greatly on the climatic conditions     
preceding the    period of vintage1 on  
the state of dryness or humidity1 as    
well as the    temperature at the time  
of gathering the grapes1 and also on the
    nature of the vines4                
,,chapter ,,vi4                 ,,the   
,,physiological ,,theory ,,of           
,,fermentation4               ,i4--,on  
the ,relations existing between ,oxygen 
and ,yeast4      ,the object of all     

science is a continuous reduction of the
 number of  unexplained phenomena4 ,it  
is observed1 for instance1 that fleshy  
fruits  are not liable to fermentation  
so long as their epidermis remains      
uninjured4 ,on the other hand1 they     
ferment very readily when they are      
piled up in heaps1 more or less open1   
and immersed in their saccharine  juice4
 ,the mass becomes heated and swells2   
carbonic acid gas is  disengaged1 and   
the sugar disappears and is replaced by 
alcohol4 ,now1 as  to the question of   
the origin of these spontaneous         
phenomena1 so  remarkable in character  
as well as usefulness for man's service1
 modern  knowledge has taught us that   
fermentation is the consequence of a    
development of vegetable cells1 the     
germs of which do not exist in the      
saccharine juices within fruits2 that   
many varieties of these cellular  plants
 exist1 each giving rise to its own     
particular fermentation4 ,the  principal
 products of these various              

fermentations1 although resembling  each
 other in their nature1 differ in their 
relative proportions and in  the        
accessory substances that accompany     
them1 a fact which alone is  sufficient 
to account for wide differences in the  
quality and commercial  value of        
alcoholic beverages4    ,now that the   
discovery of ferments and their living  
nature1 and our  knowledge of their     
origin1 may have solved the mystery of  
the  spontaneous appearance of          
fermentations in natural saccharine     
juices1 we  may ask whether we must     
still regard the reactions that occur in
 these  fermentations as phenomena      
inexplicable by the ordinary laws of    
chemistry4 ,we can readily see that     
fermentations occupy a special place  in
 the series of chemical and biological  
phenomena4 ,what gives to  fermentations
 certain exceptional characters1 of     
which we are only now  beginning to     
suspect the causes1 is the mode of life 
in the minute  plants designated under  

the generic name of ferments1 a mode of 
life  which is essentially different    
from that in other vegetables1 and from 
which result phenomena equally          
exceptional throughout the whole range  
of  the chemistry of living beings4     
,the least reflection will suffice to   
convince us that the alcoholic  ferments
 must possess the faculty of vegetating 
and performing their  functions out of  
contact with air4 ,let us consider1 for 
instance1 the  method of vintage        
practised in the ,jura4 ,the bunches are
 laid at the  foot of the vine in a     
large tub1 and the grapes there stripped
 from  them4 ,when the grapes1 some of  
which are uninjured1 others bruised1 and
  all moistened by the juice issuing    
from the latter1 fill the tub--where    
they form what is commonly called the   
vintage--they are conveyed in  barrels  
to large vessels fixed in cellars of a  
considerable depth4 ,these  vessels are 
not filled to more than three-quarters  
of their capacity4  ,fermentation soon  

takes place in them1 and the carbonic   
acid gas finds  escape through the      
bunghole1 the diameter of which1 in the 
case of the  largest vessels1 is not    
more than ten or twelve centimetres     
7about four  inches74 ,the wine is not  
drawn off before the end of two or three
  months4 ,in this way it seems highly  
probable that the yeast which  produces 
the wine under such conditions must have
 developed1 to a great  extent at least1
 out of contact with oxygen4 ,no doubt  
oxygen is not  entirely absent from the 
first2 nay1 its limited presence is even
 a  necessity to the manifestation of   
the phenomena which follow4 ,the grapes 
are stripped from the bunch in contact  
with air1 and the must which  drops from
 the wounded fruit takes a little of    
this gas into solution4  ,this small    
quantity of air so introduced into the  
must1 at the  commencement of           
operations1 plays a most indispensable  
part1 it being  from the presence of    
this that the spores of ferments which  

are spread  over the surface of the     
grapes and the woody part of the bunches
 derive  the power of starting their    
vital phenomena4#aaa ,this air1 however1
  especially when the grapes have been  
stripped from the bunches1 is in  such  
small proportion1 and that which is in  
contact with the liquid mass  is so     
promptly expelled by the carbonic acid  
gas1 which is evolved as  soon as a     
little yeast has formed1 that it will   
readily be admitted that  most of the   
yeast is produced apart from the        
influence of oxygen1  whether free or in
 solution4 ,we shall revert to this     
fact1 which is of  great importance4 ,at
 present we are only concerned in       
pointing out that1  from the mere       
knowledge of the practices of certain   
localities1 we are  induced to believe  
that the cells of yeast1 after they have
 developed  from their spores1 continue 
to live and multiply without the        
intervention of oxygen1 and that the    
alcoholic ferments have a mode of  life 

which is probably quite exceptional1    
since it is not generally met  with in  
other species1 vegetable or animal4     
,another equally exceptional            
characteristic of yeast and fermentation
 in  general consists in the small      
proportion which the yeast that forms   
bears to the sugar that decomposes4 ,in 
all other known beings the weight  of   
nutritive matter assimilated corresponds
 with the weight of food used  up1 any  
difference that may exist being         
comparatively small4 ,the life of  yeast
 is entirely different4 ,for a certain  
weight of yeast formed1 we  may have ten
 times1 twenty times1 a hundred times as
 much sugar1 or even  more decomposed1  
as we shall experimentally prove        
by-and-bye2 that is to  say1 that whilst
 the proportion varies in a precise     
manner1 according to  conditions which  
we shall have occasion to specify1 it is
 also greatly  out of proportion to the 
weight of the yeast4 ,we repeat1 the    
life of no  other being1 under its      

normal physiological conditions1 can    
show  anything similar4 ,the alcoholic  
ferments1 therefore1 present themselves 
to us as plants which possess at least  
two singular properties3 they can  live 
without air1 that is1 without oxygen1   
and they can cause  decomposition to an 
amount which1 though variable1 yet1 as  
estimated by  weight of product formed1 
is out of all proportion to the weight  
of  their own substance4 ,these are     
facts of so great importance1 and so    
intimately connected with the theory of 
fermentation1 that it is  indispensable 
to endeavour to establish them          
experimentally1 with all  the exactness 
of which they will admit4    ,the       
question before us is whether yeast is  
in reality an anarobian  plant1 and what
 quantities of sugar it may cause to    
ferment1 under the  various conditions  
under which we cause it to act4    ,the 
following experiments were undertaken to
 solve this double  problem3--,we took a
 double-necked flask1 of three litres   

7five pints7  capacity1 one of the tubes
 being curved and forming an escape for 
the  gas2 the other one1 on the right   
hand side 7,fig4 #ei71 being furnished  
with a glass tap4 ,we filled this flask 
with pure yeast-water1 sweetened  with  
#e per cent4 of sugar candy1 the flask  
being so full that there was  not the   
least trace of air remaining above the  
tap or in the escape  tube2 this        
artificial wort had1 however1 been      
itself aerated4 ,the curved  tube was   
plunged in a porcelain vessel full of   
mercury1 resting on a  firm support4 ,in
 the small cylindrical funnel above the 
tap1 the  capacity of which was from #aj
 c4c4 to #ae c4c4 7about half a fluid   
ounce7  we caused to ferment1 at a      
temperature of #bj or #be ,c4 7about #ge
 ,f471  five or six cubic centimetres of
 the saccharine liquid1 by means of a   
trace of yeast1 which multiplied        
rapidly1 causing fermentation1 and      
forming a slight deposit of yeast at the
 bottom of the funnel above the  tap4   

,we then opened the tap1 and some of the
 liquid in the funnel  entered the      
flask1 carrying with it the small       
deposit of yeast1 which  was sufficient 
to impregnate the saccharine liquid     
contained in the  flask4 ,in this manner
 it is possible to introduce as small a 
quantity of  yeast as we wish1 a        
quantity the weight of which1 we may    
say1 is hardly  appreciable4 ,the yeast 
sown multiplies rapidly and produces    
fermentation1 the carbonic acid gas from
 which is expelled into the  mercury4   
,in less than twelve days all the sugar 
had disappeared1 and the  fermentation  
had finished4 ,there was a sensible     
deposit of yeast  adhering to the sides 
of the flask2 collected and dried it    
weighed #bbe  grammes 7#cd grains74 ,it 
is evident that in this experiment the  
total  amount of yeast formed1 if it    
required oxygen to enable it to live1   
could not have absorbed1 at most1 more  
than the volume which was  originally   
held in solution in the saccharine      

liquid1 when that was  exposed to the   
air before being introduced into the    
flask4    ,illustration3 ,fig4 #ei4     
,illustration3 ,fig4 #fj4    ,some exact
 experiments conducted by ,m4 ,raulin in
 our laboratory have  established the   
fact that saccharine worts1 like water1 
soon become  saturated when shaken      
briskly with an excess of air1 and also 
that they  always take into solution a  
little less air than saturated pure     
water  contains under the same          
conditions of temperature and pressure4 
,at a  temperature of #be ,c4 7#gg ,f47 
therefore1 if we adopt the coefficient  
of  the solubility of oxygen in water   
given in ,bunsen's tables1 we find that 
#a litre 7#a-c_/d pints7 of water       
saturated with air contains #ee c4c4    
7#jc  cubic inch7 of oxygen4 ,the three 
litres of yeast-water in the flask1     
supposing it to have been saturated1    
contained less than #afe c4c4 7#a  cubic
 inch7 of oxygen1 or1 in weight1 less   
than #bc milligrammes 7#jce  grains74   

,this was the maximum amount of oxygen1 
supposing the greatest  possible        
quantity to have been absorbed1 that was
 required by the yeast  formed in the   
fermentation of #aej grammes 7#dh ,troy 
ounces7 of sugar4 ,we  shall better     
understand the significance of this     
result later on4 ,let us  repeat the    
foregoing experiment1 but under altered 
conditions4 ,let us  fill1 as before1   
our flask with sweetened yeast-water1   
but let this be  first boiled1 so as to 
expel all the air it contains4 ,to      
effect this we  arrange our apparatus as
 represented in the accompanying sketch 
7,fig4  #fj74 ,we place our flask1 ,a1  
on a tripod above a gas flame1 and in   
place  of the vessel of mercury         
substitute a porcelain dish1 under which
 we can  put a gas flame1 and which     
contains some fermentable1 saccharine   
liquid1  similar to that with which the 
flask is filled4 ,we boil the liquid in 
the flask and that in the basin         
simultaneously1 and then let them cool  

down together1 so that as the liquid in 
the flask cools some of the  liquid is  
sucked from the basin into the flask4   
,from a trial experiment  which we      
conducted1 determining the quantity of  
oxygen that remained in  solution in the
 liquid after cooling1 according to ,m4 
,schtzenberger's  valuable method1 by   
means of hydrosulphite of soda1#aab we  
found that  the three litres in the     
flask1 treated as we have described1    
contained  less than one milligramme    
7#jjae grain7 of oxygen4 ,at the same   
time we  conducted another experiment1  
by way of comparison 7,fig4 #fa74 ,we   
took a  flask1 ,b1 of larger capacity   
than the former one1 which we filled    
about  half with the same volume as     
before of a saccharine liquid of        
identically the same composition4 ,this 
liquid had been previously freed  from  
alterative germs by boiling4 ,in the    
funnel surmounting ,a1 we put a  few    
cubic centimetres of saccharine liquid  
in a state of fermentation1  and when   

this small quantity of liquid was in    
full fermentation1 and the  yeast in it 
was young and vigorous1 we opened the   
tap1 closing it again  immediately1 so  
that a little of the liquid and yeast   
still remained in  the funnel4 ,by this 
means we caused the liquid in ,a to     
ferment4 ,we also  impregnated the      
liquid in ,b with some yeast taken from 
the funnel of ,a4  ,we then replaced the
 porcelain dish in which the curved     
escape tube of ,a  had been plunged1 by 
a vessel filled with mercury4           
,illustration3 ,fig4 #fa4    ,the       
following is a description of two of    
these comparative fermentations  and the
 results they gave4    ,the fermentable 
liquid was composed of yeast-water      
sweetened with #e per  cent4 of         
sugar-candy2 the ferment employed was   
saccharomyces  pastorianus4    ,the     
impregnation took place on ,january     
#bjth4 ,the flasks were placed in  an   
oven at #be ,c4 7#gg ,f474      ,flask  
,a1 without air4          ,january      

#bast4--,fermentation commenced2 a      
little frothy liquid issued      from   
the escape-tube and covered the mercury4
        ,the following days1            
fermentation was active4 ,examining the 
yeast      mixed with the froth that was
 expelled into the mercury by the       
evolution of carbonic acid gas1 we found
 that it was very fine1      young1 and 
actively budding4        ,february      
#crd4--,fermentation still continued1   
showing itself by a      number of      
little bubbles rising from the bottom of
 the liquid1 which      had settled     
bright4 ,the yeast was at the bottom in 
the form of a      deposit4             
,february #gth4--,fermentation still    
continued1 but very languidly4          
,february #ith4--,a very languid        
fermentation still went on1 discernible 
in little bubbles rising from the bottom
 of the flask4      ,flask ,b1 with air4
          ,january #bast4--,a sensible  
development of yeast4        ,the       
following days1 fermentation was active1

 and there was an      abundant froth on
 the surface of the liquid4             
,february #ast4--,all symptoms of       
fermentation had ceased4    ,as the     
fermentation in ,a would have continued 
for a long time1 being so  very languid1
 and as that in ,b had been finished for
 several days1 we  brought to a close   
our two experiments on ,february #ith4  
,to do this we  poured off the liquids  
in ,a and ,b1 collecting the yeasts on  
tared  filters4 ,filtration was an easy 
matter1 more especially in the case of  
,a4 ,examining the yeasts under the     
microscope1 immediately after           
decantation1 we found that both of them 
remained very pure4 ,the yeast in  ,a   
was in little clusters1 the globules of 
which were collected together1  and     
appeared by their well defined borders  
to be ready for an easy  revival in     
contact with air4    ,as might have been
 expected1 the liquid in the flask ,b   
did not contain  the least trace of     
sugar2 that in the flask ,a still       

contained some1 as  was evident from the
 non-completion of fermentation1 but not
 more than  #df grammes 7#ga grains74   
,now1 as each flask originally contained
 #c  litres of liquid1 holding in       
solution #e per cent4 of sugar1 it      
follows  that #aej grammes 7#b1caj      
grains7 of sugar had fermented in the   
flask ,b1  and #aded grammes 7#b1bcib   
grains7 in the flask ,a4 ,the weights of
 yeast  after drying at #ajj ,c4 7#bab  
,f47 were--         ,for the flask ,b1  
with air      #aigj grammes 7#cjd       
grains74       ,for the flask ,a1       
without air   #acfh grammes4#aac    ,the
 proportions were #a of yeast to #gf of 
fermented sugar in the first  case1 and 
#a of yeast to #hi of fermented sugar in
 the second4    ,from these facts the   
following consequences may be deduced3  
#a4 ,the fermentable liquid 7flask ,b71 
which since it had been in contact  with
 air1 necessarily held air in solution1 
although not to the point of            
saturation1 inasmuch as it had been once

 boiled to free it from all  foreign    
germs1 furnished a weight of yeast      
sensibly greater than that  yielded by  
the liquid which contained no air at all
 7flask ,a71 or1 at  least1 which could 
only have contained an exceedingly      
minute quantity4    #b4 ,this same      
slightly aerated fermentable liquid     
fermented much more  rapidly than the   
other4 ,in eight or ten days it         
contained no more sugar2  while the     
other1 after twenty days1 still         
contained an appreciable  quantity4     
,is this last fact to be explained by   
the greater quantity of yeast  formed in
 ,b8 ,by no means4 ,at first1 when the  
air has access to the  liquid1 much     
yeast is formed and little sugar        
disappears1 as we shall  prove          
immediately2 nevertheless the yeast     
formed in contact with the air  is more 
active than the other4 ,fermentation is 
correlative1 first to the  development  
of the globules1 and then to the        
continued life of those  globules once  

formed4 ,the more oxygen these last     
globules have at their  disposal during 
their formation1 the more vigorous1     
transparent1 and  turgescent1 and1 as a 
consequence of this last quality1 the   
more active  they are in decomposing    
sugar4 ,we shall revert hereafter to    
these facts4    #c4 ,in the airless     
flask the proportion of yeast to sugar  
was #a_/hi2 it  was only #a_/gf in the  
flask which had air at first4    ,the   
proportion that the weight of yeast     
formed bears to the weight of  the sugar
 is1 therefore1 variable1 and this      
variation depends1 to a  certain extent1
 upon the presence of air and the       
possibility of oxygen  being absorbed by
 the yeast4 ,we shall presently show    
that yeast  possesses the power of      
absorbing that gas and emitting carbonic
 acid1  like ordinary fungi1 that even  
oxygen may be reckoned amongst the      
number  of food-stuffs that may be      
assimilated by this plant1 and that this
  fixation of oxygen in yeast1 as well  

as the oxidations resulting from  it1   
have the most marked effect on the life 
of yeast1 on the  multiplication of its 
cells1 and on their activity as ferments
 acting  upon sugar1 whether immediately
 or afterwards1 apart from supplies of  
oxygen or air4    ,in the preceding     
experiment1 conducted without the       
presence of air1  there is one          
circumstance particularly worthy of     
notice4 ,this experiment  succeeds1 that
 is to say1 the yeast sown in the medium
 deprived of  oxygen develops1 only when
 this yeast is in a state of great      
vigour4 ,we  have already explained the 
meaning of this last expression4 ,but we
 wish  now to call attention to a very  
evident fact in connection with this    
point4 ,we impregnate a fermentable     
liquid2 yeast develops and  fermentation
 appears4 ,this lasts for several days  
and then ceases4 ,let  us suppose that1 
from the day when fermentation first    
appears in the  production of a minute  
froth1 which gradually increases till it

 whitens  the surface of the liquid1 we 
take1 every twenty-four hours1 or at    
longer intervals1 a trace of the yeast  
deposited on the bottom of the  vessel  
and use it for starting fresh           
fermentations4 ,conducting these        
fermentations all under precisely the   
same conditions of temperature1         
character1 and volume of liquid1 let us 
continue this for a prolonged  time1    
even after the original fermentation is 
finished4 ,we shall have no  difficulty 
in seeing that the first signs of action
 in each of our  series of second       
fermentations appear always later and   
later in  proportion to the length of   
time that has elapsed from the          
commencement  of the original           
fermentation4 ,in other words1 the time 
necessary for the  development of the   
germs and the production of that amount 
of yeast  sufficient to cause the first 
appearance of fermentation varies with  
the  state of the impregnating cells1   
and is longer in proportion as the      

cells are further removed from the      
period of their formation4 ,it is       
essential1 in experiments of this kind1 
that the quantities of yeast            
successively taken should be as nearly  
as possible equal in weight or  volume1 
since1 ceteris paribus1 fermentations   
manifest themselves more  quickly the   
larger the quantity of yeast employed in
 impregnation4    ,if we compare under  
the microscope the appearance and       
character of the  successive quantities 
of yeast taken1 we shall see plainly    
that the  structure of the cells        
undergoes a progressive change4 ,the    
first sample  which we take1 quite at   
the beginning of the original           
fermentation1  generally gives us cells 
rather larger than those later on1 and  
possessing a remarkable tenderness4     
,their walls are extremely thin1 the    
consistency and softness of their       
protoplasm is akin to fluidity1 and     
their granular contents appear in the   
form of scarcely visible spots4  ,the   

borders of the cells soon become more   
marked1 a proof that their  walls       
undergo a thickening2 their protoplasm  
also becomes denser1 and  the           
granulations more distinct4 ,cells of   
the same organ1 in the states  of       
infancy and old age1 should not differ  
more than the cells of which  we are    
speaking1 taken in their extreme states4
 ,the progressive changes  in the cells1
 after they have acquired their normal  
form and volume1  clearly demonstrate   
the existence of a chemical work of a   
remarkable  intensity1 during which     
their weight increases1 although in     
volume they  undergo no sensible change1
 a fact that we have often characterized
 as  8the continued life of cells       
already formed40 ,we may call this work 
a  process of maturation on the part of 
the cells1 almost the same that we  see 
going on in the case of adult beings in 
general1 which continue to  live for a  
long time1 even after they have become  
incapable of  reproduction1 and long    

after their volume has become           
permanently fixed4    ,this being so it 
is evident1 we repeat1 that1 to multiply
 in a  fermentable medium1 quite out of 
contact with oxygen1 the cells of yeast 
must be extremely young1 full of life   
and health1 and still under the         
influence of the vital activity which   
they owe to the free oxygen which  has  
served to form them1 and which they have
 perhaps stored up for a  time4 ,when   
older1 they reproduce themselves with   
much difficulty when  deprived of air1  
and gradually become more languid2 and  
if they do  multiply1 it is in strange  
and monstrous forms4 ,a little older    
still1  they remain absolutely inert in 
a medium deprived of free oxygen4 ,this 
is not because they are dead2 for in    
general they may be revived in a        
marvellous manner in the same liquid if 
it has been first aerated before  they  
are sown4 ,it would not surprise us to  
learn that at this point  certain       
preconceived ideas suggest themselves to

 the mind of an  attentive reader on the
 subject of the causes that may serve to
 account  for such strange phenomena in 
the life of these beings which our      
ignorance hides under the expressions of
 youth and age2 this1  however1 is a    
subject that we cannot pause to consider
 here4    ,at this point we must        
observe--for it is a matter of great    
importance--that1 in the operations of  
the brewer there is always a time  when 
the yeasts are in this state of vigorous
 youth of which we have  been speaking1 
acquired under the influence of free    
oxygen1 since all  the worts and all the
 yeasts of commerce are necessarily     
manipulated in  contact with air1 and so
 impregnated more or less with oxygen4  
,the yeast  immediately seizes upon this
 gas and acquires a state of freshness  
and  activity1 which permits it to live 
afterwards out of contact with air1  and
 to act as a ferment4 ,thus1 in ordinary
 brewery practice1 we find the  yeast   
already formed in abundance even before 

the earliest external  signs of         
fermentation have made their appearance4
 ,in this first phase of  its existence1
 yeast lives chiefly like an ordinary   
fungus4    ,from the same circumstances 
it is clear that the brewer's           
fermentations  may1 speaking quite      
strictly1 last for an indefinite time1  
in  consequence of the unceasing supply 
of fresh wort1 and from the fact1       
moreover1 that the exterior air is      
constantly being introduced during  the 
work1 and that the air contained in the 
fresh worts keeps up the  vital activity
 of the yeast1 as the act of breathing  
keeps up the vigour  and life of cells  
in all living beings4 ,if the air could 
not renew  itself in any way1 the vital 
activity which the cells originally     
received1 under its influence1 would    
become more and more exhausted1 and  the
 fermentation eventually come to an end4
    ,we may recount one of the results  
obtained in other experiments similar   
to the last1 in which1 however1 we      

employed yeast which was still older    
than that used for our experiment with  
flask ,a 7,fig4 #fj71 and moreover  took
 still greater precautions to prevent   
the presence of air4 ,instead  of       
leaving the flask1 as well as the dish1 
to cool slowly1 after having  expelled  
all air by boiling1 we permitted the    
liquid in the dish to  continue boiling 
whilst the flask was being cooled by    
artificial means2  the end of the escape
 tube was then taken out of the still   
boiling dish  and plunged into the      
mercury trough4 ,in impregnating the    
liquid1 instead  of employing the       
contents of the small cylindrical funnel
 whilst still  in a state of            
fermentation1 we waited until this was  
finished4 ,under  these conditions1     
fermentation was still going on in our  
flask1 after a  lapse of three months4  
,we stopped it and found that #jbee     
gramme 7#ci  grains7 of yeast had been  
formed1 and that #de grammes 7#fic      
grains7 of  sugar had fermented1 the    

ratio between the weights of yeast and  
sugar  being thus #jbee_/de  #a_/agf4   
,in this experiment the yeast developed 
with  much difficulty1 by reason of the 
conditions to which it had been         
subjected4 ,in appearance the cells     
varied much1 some were to be found      
large1 elongated1 and of tubular aspect1
 some seemed very old and were          
extremely granular1 whilst others were  
more transparent4 ,all of them  might be
 considered abnormal cells4    ,in such 
experiments we encounter another        
difficulty4 ,if the yeast sown  in the  
non-aerated fermentable liquid is in the
 least degree impure1  especially if we 
use sweetened yeast-water1 we may be    
sure that  alcoholic fermentation will  
soon cease1 if1 indeed1 it ever         
commences1  and that accessory          
fermentations will go on4 ,the vibrios  
of butyric  fermentation1 for instance1 
will propagate with remarkable facility 
under these circumstances4 ,clearly     
then1 the purity of the yeast at the    

moment of impregnation1 and the purity  
of the liquid in the funnel1 are        
conditions indispensable to success4    
,to secure the latter of these          
conditions1 we close the funnel1 as     
shown  in ,fig4 #fj1 by means of a cork 
pierced with two holes1 through one of  
which a short tube passes1 to which a   
short length of india-rubber  tubing    
provided with a glass stopper is        
attached2 through the other hole  a thin
 curved tube is passed4 ,thus fitted1   
the funnel can answer the  same purposes
 as our double-necked flasks4 ,a few    
cubic centimetres of  sweetened         
yeast-water are then put in it and      
boiled1 so that the steam  may destroy  
any germs adhering to the sides4 ,when  
cold the liquid is  impregnated by means
 of a trace of pure yeast1 introduced   
through the  glass-stoppered tube4 ,if  
these precautions are neglected it is   
scarcely  possible to secure a          
successful fermentation in our flasks1  
because the  yeast sown is immediately  

held in check by a development of       
anarobian  vibrios4 ,for greater        
security1 we may add to the fermentable 
liquid1 at  the moment when it is       
prepared1 a very small quantity of      
tartaric acid1  which will prevent the  
development of butyric vibrios4         
,illustration3 ,fig4 #fb4    ,the       
variation of the ratio between the      
weight of the yeast and that of  the    
sugar decomposed by it now claims       
special attention4 ,side by side  with  
the experiments which we have just      
described1 we conducted a third  lot by 
means of the flask ,c 7,fig4 #fb71      
holding #dg litres 7#h-a_/d pints71  and
 fitted up like the usual two-necked    
flasks1 with the object of  freeing the 
fermentable liquid from foreign germs1  
by boiling it to  begin with1 so that we
 might carry on our work under          
conditions of  purity4 ,the volume of   
yeast-water 7containing #e per cent4 of 
sugar7 was  only #bjj c4c4 7#g fl4 oz471
 and consequently1 taking into account  

the  capacity of the flask1 it formed   
but a very thin layer at the bottom4 ,on
  the day after impregnation the deposit
 of yeast was already  considerable1 and
 forty-eight hours afterwards the       
fermentation was  completed4 ,on the    
third day we collected the yeast1 after 
having  analyzed the gas contained in   
the flask4 ,this analysis was easily    
accomplished by placing the flask in a  
hot-water bath1 whilst the end of  the  
curved tube was plunged under a cylinder
 of mercury4 ,the gas  contained #dad   
per cent4 of carbonic acid1 and1 after  
the absorption1  the remaining air      
contained--                             
,oxygen           #aig                  
,nitrogen         #hjc                  
-----                                   
#ajjj    ,taking into consideration the 
volume of the flask1 this shows a       
minimum  of #ej c4c4 7#cje cub4 in47 of 
oxygen to have been absorbed by the     
yeast4  ,the liquid contained no more   
sugar1 and the weight of the yeast1     

dried  at a temperature of #ajj ,c4     
7#bab ,f471 was #jdd gramme 7#fh        
grains74 ,the  ratio between the weight 
of the yeast and that of the sugar was1 
therefore1 #jdd_/aadaj  #a_/bbg4 ,on    
this occasion1 where we had  increased  
the quantity of oxygen held in solution1
 so as to yield itself  for assimilation
 at the beginning and during the earlier
 developments of  the yeast1 we found   
instead of the previous ratio of #a_/gf 
that of #a_/bc4    ,illustration3 ,fig4 
#fc4    ,the next experiment was to     
increase the proportion of oxygen to a  
still  greater extent1 by rendering the 
diffusion of gas a more easy matter     
than it is in a flask1 the air in which 
is in a state of perfect  quiescence4   
,such a state of matters hinders the    
supply of oxygen1  inasmuch as the      
carbonic acid1 as soon as it is         
liberated1 at once forms  an immovable  
layer on the surface of the liquid1 and 
so separates off  the oxygen4 ,to effect
 the purpose of our present experiment1 

we used  flat basins having glass       
bottoms and low sides1 also of glass1 in
 which  the depth of the liquid is not  
more than a few millimetres 7less than  
#a_/d-;inch7 7,fig4 #fc74 ,the following
 is one of our experiments so           
conducted3--,on ,april #afth1 #ahfj1 we 
sowed a trace of beer yeast 78high0     
yeast7 in #bjj c4c4 7#g fl4 oz47 of a   
saccharine liquid containing #agbj      
grammes 7#bfb grains7 of sugar-candy4   
,from ,april #ahth our yeast was in     
good condition and well developed4 ,we  
collected it1 after having added  to the
 liquid a few drops of concentrated     
sulphuric acid1 with the  object of     
checking the fermentation to a great    
extent1 and facilitating  filtration4   
,the sugar remaining in the filtered    
liquid1 determined by  ,fehling's       
solution1 showed that #ajd grammes 7#af 
grains7 of sugar had  disappeared4 ,the 
weight of the yeast1 dried at #ajj ,c4  
7#bab ,f471 was  #jabg gramme 7#b       
grains71 which gives us the ratio       

between the weight of  the yeast and    
that of the fermented sugar             
,illustration3 ,formula #a3 #jabg_/ajd  
#a_/ha4    which is considerably higher 
than the preceding ones4    ,we may     
still further increase this ratio by    
making our estimation as  soon as       
possible after the impregnation1 or the 
addition of the ferment4  ,it will be   
readily understood why yeast1 which is  
composed of cells that  bud and         
subsequently detach themselves from one 
another1 soon forms a  deposit at the   
bottom of the vessels4    ,in           
consequence of this habit of growth1 the
 cells constantly covering  each other  
prevents the lower layers from having   
access to the oxygen  held in solution  
in the liquid1 which is absorbed by the 
upper ones4  ,hence1 those which are    
covered and deprived of this gas act on 
the sugar  without deriving any vital   
benefit from the oxygen--a circumstance 
which  must tend to diminish the ratio  
of which we are speaking4 ,once more    

repeating the preceding experiment1 but 
stopping it as soon as we think  that   
the weight of yeast formed may be       
determined by the balance 7we  find that
 this may be done twenty-four hours     
after impregnation with an              
inappreciable quantity of yeast7 in this
 case the ratio between the  weights of 
yeast and sugar is    ,illustration3    
,formula #b3 7#j;gr#jbd                 
yeast7_/7#j;gr#jih sugar7  #a_/d4       
,this is the highest ratio that we have 
been able to obtain4    ,under these    
conditions the fermentation of sugar is 
extremely languid3  the ratio obtained  
is very nearly the same that ordinary   
fungoid growths  would give4 ,the       
carbonic acid evolved is principally    
formed by the  decompositions which     
result from the assimilation of         
atmospheric oxygen4  ,the yeast1        
therefore1 lives and performs its       
functions after the manner  of ordinary 
fungi3 so far it is no longer a ferment1
 so to say2  moreover1 we might expect  

to find it cease to be a ferment at all 
if we  could only surround each cell    
separately with all the air that it     
required4 ,this is what the preceding   
phenomena teach us2 we shall have       
occasion to compare them later on with  
others which relate to the vital  action
 exercised on yeast by the sugar of     
milk4    ,we may here be permitted to   
make a digression4    ,in his work on   
fermentations1 which ,m4 ,schtzenberger 
has recently  published1 the author     
criticises the deductions that we have  
drawn from  the preceding experiments1  
and combats the explanation which we    
have  given of the phenomena of         
fermentation4#aae ,it is an easy matter 
to  show the weak point of ,m4          
,schtzenberger's reasoning4 ,we         
determined the  power of the ferment by 
the relation of the weight of sugar     
decomposed  to the weight of yeast      
produced4 ,m4 ,schtzenberger asserts    
that in doing  this we lay down a       
doubtful hypothesis1 and he thinks that 

this power1  which he terms fermentative
 energy1 may be estimated more correctly
 by  the quantity of sugar decomposed by
 the unit-weight of yeast in  unit-time2
 moreover1 since our experiments show   
that yeast is very  vigorous when it has
 a sufficient supply of oxygen1 and     
that1 in such a  case1 it can decompose 
much sugar in a little time1 ,m4        
,schtzenberger  concludes that it must  
then have great power as a ferment1 even
 greater  than it has when it performs  
its functions without the aid of air1   
since  under this condition it          
decomposes sugar very slowly4 ,in short1
 he is  disposed to draw from our       
observations the very opposite          
conclusion to  that which we arrived at4
    ,m4 ,schtzenberger has failed to    
notice that the power of a ferment is   
independent of the time during which it 
performs its functions4 ,we  placed a   
trace of yeast in one litre of          
saccharine wort2 it propagated1  and all
 the sugar was decomposed4 ,now1 whether

 the chemical action  involved in this  
decomposition of sugar had required for 
its completion  one day1 or one month1  
or one year1 such a factor was of no    
more  importance in this matter than the
 mechanical labour required to raise a  
ton of materials from the ground to the 
top of a house would be affected  by the
 fact that it had taken twelve hours    
instead of one4 ,the notion of  time has
 nothing to do with the definition of   
work4 ,m4 ,schtzenberger  has not       
perceived that in introducing the       
consideration of time into the          
definition of the power of a ferment1 he
 must introduce1 at the same  time1 that
 of the vital activity of the cells1    
which is independent of  their character
 as a ferment4 ,apart from the          
consideration of the  relation existing 
between the weight of fermentable       
substance decomposed  and that of       
ferment produced1 there is no occasion  
to speak of  fermentations or of        
ferments4 ,the phenomena of fermentation

 and of  ferments have been placed apart
 from others1 precisely because1 in     
certain chemical actions1 that ratio has
 been out of proportion2 but the  time  
that these phenomena require for their  
accomplishment has nothing  to do either
 with their existence proper1 or with   
their power4 ,the cells  of a ferment   
may1 under some circumstances1 require  
eight days for  revival and propagation1
 whilst1 under other conditions1 only a 
few  hours are necessary2 so that1 if we
 introduce the notion of time into  our 
estimate of their power of              
decomposition1 we may be led to conclude
  that in the first case that power was 
entirely wanting1 and that in the       
second case it was considerable1        
although all the time we are dealing    
with the same organism--the identical   
ferment4    ,m4 ,schtzenberger is       
astonished that fermentation can take   
place in the  presence of free oxygen1  
if1 as we suppose1 the decomposition of 
the  sugar is the consequence of the    

nutrition of the yeast1 at the expense  
of the combined oxygen1 which yields    
itself to the ferment4 ,at all  events1 
he argues1 fermentation ought to be     
slower in the presence of  free oxygen4 
,but why should it be slower8 ,we have  
proved that in the  presence of oxygen  
the vital activity of the cells         
increases1 so that1  as far as rapidity 
of action is concerned1 its power cannot
 be  diminished4 ,it might1             
nevertheless1 be weakened as a ferment1 
and this  is precisely what happens4    
,free oxygen imparts to the yeast an    
increased  vital activity1 but at the   
same time impairs rapidly its power as  
yeast--qu yeast1 inasmuch as under this 
condition it approaches the  state in   
which it can carry on its vital         
processes after the manner of  an       
ordinary fungus2 the mode of life1 that 
is1 in which the ratio  between the     
weight of sugar decomposed and the      
weight of the new cells  produced will  
be the same as holds generally among    

organisms which are  not ferments4 ,in  
short1 varying our form of expression a 
little1 we may  conclude with perfect   
truth1 from the sum total of observed   
facts1 that  the yeast which lives in   
the presence of oxygen and can          
assimilate as  much of that gas as is   
necessary to its perfect nutrition1     
ceases  absolutely to be a ferment at   
all4 ,nevertheless1 yeast formed under  
these conditions and subsequently       
brought into the presence of sugar1  out
 of the influence of air1 would         
decompose more in a given time  than in 
any other of its states4 ,the reason is 
that yeast which has  formed in contact 
with air1 having the maximum of free    
oxygen that it  can assimilate1 is      
fresher and possessed of greater vital  
activity than  that which has been      
formed without air or with an           
insufficiency of air4  ,m4              
,schtzenberger would associate this     
activity with the notion of time  in    
estimating the power of the ferment2 but

 he forgets to notice that  yeast can   
only manifest this maximum of energy    
under a radical change of  its          
life-conditions2 by having no more air  
at its disposal and breathing  no more  
free oxygen4 ,in other words1 when its  
respiratory power becomes  null1 its    
fermentative power is at its greatest4  
,m4 ,schtzenberger  asserts exactly the 
opposite 7p4 #aea of his work--,paris1  
#ahge71aaf and  so gratuitously places  
himself in opposition to facts4         
,illustration3 ,fig4 #fd4    ,in        
presence of abundant air-supply1 yeast  
vegetates with extraordinary  activity4 
,we see this in the weight of new yeast1
 comparatively large1  that may be      
formed in the course of a few hours4    
,the microscope still  more clearly     
shows this activity in the rapidity of  
budding1 and the  fresh and active      
appearance of all the cells4 ,fig4 #fd  
represents the  yeast of our last       
experiment at the moment when we stopped
 the  fermentation4 ,nothing has been   

taken from imagination1 all the groups  
have been faithfully sketched as they   
were4#aag    ,in passing it is of       
interest to note how promptly the       
preceding results  were turned to good  
account practically4 ,in well-managed   
distilleries1  the custom of aerating   
the wort and the juices1 to render them 
more  adapted to fermentation1 has been 
introduced4 ,the molasses1 mixed with   
water1 is permitted to run in thin      
threads through the air at the moment   
when the yeast is added4 ,manufactories 
have been erected1 in which the         
manufacture of yeast is almost          
exclusively carried on4 ,the saccharine 
worts1 after the addition of yeast1 are 
left to themselves1 in contact  with    
air1 in shallow vats of large           
superficial area1 realizing thus on  an 
immense scale the conditions of the     
experiments which we undertook in       
#ahfa1 and which we have already        
described in determining the rapid and  
easy multiplication of yeast in contact 

with air4    ,the next experiment       
attempted was to determine the volume of
 oxygen  absorbed by a known quantity of
 yeast1 the yeast living in contact with
  air1 and under such conditions that   
the absorption of air was  comparatively
 easy and abundant4    ,illustration3   
,fig4 #fe4    ,with this object we      
repeated the experiment that we         
performed with the  large-bottomed flask
 7,fig4 #fb71 employing a vessel shaped 
like ,fig4 ,b4  7,fig4 #fe71 which is1  
in point of fact1 the flask ,a with its 
neck drawn  out and closed in a flame1  
after the introduction of a thin layer  
of  some saccharine juice impregnated   
with a trace of pure yeast4 ,the        
following are the data and results of an
 experiment of this kind4    ,we        
employed #fj c4c4 7about #b fluid       
ounces7 of yeast-water1 sweetened  with 
#b per cent4 of sugar and impregnated   
with a trace of yeast4 ,after  having   
subjected our vessel to a temperature of
 #be ,c4 7#gg ,f47 in an  oven for      

fifteen hours1 the drawn-out point was  
brought under an  inverted jar filled   
with mercury and the point broken off4  
,a portion of  the gas escaped and was  
collected in the jar4    ,for #be c4c4  
of this gas we found1 after absorption  
by potash1 #bjf1 and  after absorption  
by pyrogallic acid1 #agc4 ,taking into  
account the  volume which remained free 
in the flask1 which held #cae c4c41     
there was  a total absorption of #ade   
c4c4 7#jhh cub4 in47 of oxygen4#aah ,the
  weight of yeast1 in a state of        
dryness1 was #jjce gramme4    ,it       
follows that in the production of #ce   
milligrammes 7#jebd grain7 of  yeast    
there was an absorption of #ad or #ae   
c4c4 7about #g_/h cubic inch7 of        
oxygen1 even supposing that the yeast   
was formed entirely under the  influence
 of that gas3 this is equivalent to not 
less than #dad c4c4 for  #a gramme of   
yeast 7or about #cc cubic inches for    
every #bj grains74#aai    ,such is the  
large volume of oxygen necessary for the

 development of one  gramme of yeast    
when the plant can assimilate this gas  
after the manner  of an ordinary fungus4
    ,let us now return to the first     
experiment described in this paragraph  
7page #bch71 in which a flask of three  
litres capacity was filled with         
fermentable liquid1 which1 when caused  
to ferment1 yielded #bbe grammes  of    
yeast1 under circumstances where it     
could not obtain a greater supply  of   
free oxygen than #afe c4c4 7about one   
cubic inch74 ,according to what  we have
 just stated1 if this #bbe grammes 7#cd 
grains7 of yeast had not  been able to  
live without oxygen1 in other words1 if 
the original cells  had been unable to  
multiply otherwise than by absorbing    
free oxygen1 the  amount of that gas    
required could not have been less than  
#bbe  #dad  c4c41 that is1 #icae c4c4   
7#efhe cubic inches74 ,the greater part 
of the  #bbe grammes1 therefore1 had    
evidently been produced as the growth of
 an  anarobian plant4    ,ordinary fungi

 likewise require large quantities of   
oxygen for their  development1 as we may
 easily prove by cultivating any mould  
in a closed  vessel full of air1 and    
then taking the weight of plant formed  
and  measuring the volume of oxygen     
absorbed4 ,to do this1 we take a flask  
of  the shape shown in ,fig4 #ff1       
capable of holding about #cjj c4c4 7#aj-
  fluid ounces71 and containing a liquid
 adapted to the life of moulds4 ,we     
boil this liquid and seal the drawn-out 
point1 after the steam has  expelled the
 air wholly or in part2 we then open the
 flask in a garden  or in a room4       
,should a fungus-spore enter the flask1 
as will invariably  be the case in a    
certain number of flasks out of several 
used in the  experiment1 except under   
special circumstances1 it will develop  
there  and gradually absorb all the     
oxygen contained in the air of the      
flask4  ,measuring the volume of this   
air1 and weighing1 after drying1 the    
amount  of plant formed1 we find that   

for a certain quantity of oxygen        
absorbed  we have a certain weight of   
mycelium1 or of mycelium together with  
its  organs of fructification4 ,in an   
experiment of this kind1 in which the   
plant was weighed a year after its      
development1 we found for #jjjh  gramme 
7#jabc grain7 of mycelium1 dried at #ajj
 ,c4 7#bab ,f471 an  absorption that    
amounted to not less than #dc c4c4 7#ae 
cubic inches7 of  oxygen1 at #be4 ,these
 numbers1 however1 must vary sensibly   
with the  nature of the mould employed1 
and also with the greater or less       
activity  of its development1 because   
the phenomenon is complicated by the    
presence of accessory oxidations1 such  
as we find in the case of  mycoderma    
vini and aceti1 to which cause the large
 absorption of  oxygen in our last      
experiment may doubtless be             
attributed4#abj    ,illustration3 ,fig4 
#ff4    ,the conclusions to be drawn    
from the whole of the preceding facts   
can  scarcely admit of doubt4 ,as for   

ourselves1 we have no hesitation in     
finding in them the foundation of the   
true theory of fermentation4 ,in  the   
experiments which we have described1    
fermentation by yeast1 that is  to say1 
by the type of ferments properly so     
called1 is presented to us1  in a word1 
as the direct consequence of the        
processes of nutrition1  assimilation1  
and life1 when these are carried on     
without the agency of  free oxygen4 ,the
 heat required in the accomplishment of 
that work must  necessarily have been   
borrowed from the decomposition of the  
fermentable  matter1 that is from the   
saccharine substance which1 like other  
unstable  substances1 liberates heat in 
undergoing decomposition4 ,fermentation 
by  means of yeast appears1 therefore1  
to be essentially connected with the    
property possessed by this minute       
cellular plant of performing its        
respiratory functions1 somehow or other1
 with oxygen existing combined  in      
sugar4 ,its fermentative power--which   

power must not be confounded with  the  
fermentative activity or the intensity  
of decomposition in a given             
time--varies considerably between two   
limits1 fixed by the greatest and  least
 possible access to free oxygen which   
the plant has in the process  of        
nutrition4 ,if we supply it with a      
sufficient quantity of free oxygen  for 
the necessities of its life1 nutrition1 
and respiratory combustions1  in other  
words1 if we cause it to live after the 
manner of a mould1  properly so called1 
it ceases to be a ferment1 that is1 the 
ratio  between the weight of the plant  
developed and that of the sugar         
decomposed1 which forms its principal   
food1 is similar in amount to that  in  
the case of fungi4#aba ,on the other    
hand1 if we deprive the yeast of  air   
entirely1 or cause it to develop in a   
saccharine medium deprived of  free     
oxygen1 it will multiply just as if air 
were present1 although with  less       
activity1 and under these circumstances 

its fermentative character  will be most
 marked2 under these circumstances1     
moreover1 we shall find  the greatest   
disproportion1 all other conditions     
being the same1 between  the weight of  
yeast formed and the weight of sugar    
decomposed4 ,lastly1  if free oxygen    
occurs in varying quantities1 the       
ferment-power of the  yeast may pass    
through all the degrees comprehended    
between the two  extreme limits of which
 we have just spoken4 ,it seems to us   
that we  could not have a better proof  
of the direct relation that fermentation
  bears to life1 carried on in the      
absence of free oxygen1 or with a       
quantity of that gas insufficient for   
all the acts of nutrition and           
assimilation4    ,another equally       
striking proof of the truth of this     
theory is the fact1  demonstrated in    
,chapter ,,iv41 that the ordinary moulds
 assume the  character of a ferment when
 compelled to live without air1 or with 
quantities of air too scant to permit of

 their organs having around them  as    
much of that element as is necessary for
 their life as arobian  plants4         
,ferments1 therefore1 only possess in a 
higher degree a character  which belongs
 to many common moulds1 if not to all1  
and which they  share1 probably1 more or
 less1 with all living cells1 namely the
 power  of living either an arobian or  
anarobian life1 according to the        
conditions under which they are placed4 
,it may be readily understood how1 in   
their state of arobian life1 the        
alcoholic ferments have failed to       
attract attention4 ,those ferments are  
only cultivated out of contact with air1
 at the bottom of liquids which  soon   
become saturated with carbonic acid gas4
 ,air is only present in the  earlier   
developments of their germs1 and without
 attracting the  attention of the       
operator1 whilst in their state of      
anarobian growth  their life and action 
are of prolonged duration4 ,we must have
 recourse  to special experimental      

apparatus to enable us to demonstrate   
the mode  of life of alcoholic ferments 
under the influence of free oxygen2 it  
is  their state of existence apart from 
air1 in the depths of liquids that      
attracts all our attention4 ,the results
 of their action are1 however1          
marvellous1 if we regard the products   
resulting from them1 in the  important  
industries of which they are the life   
and soul4 ,in the case of  ordinary     
moulds1 the opposite holds good4 ,what  
we want to use special  experimental    
apparatus for with them is to enable us 
to demonstrate the  possibility of their
 continuing to live for a time out of   
contact with  air1 and all our          
attention1 in their case1 is attracted  
by the facility  with which they develop
 under the influence of oxygen4 ,thus   
the  decomposition of saccharine        
liquids1 which is the consequence of the
  life of fungi without air1 is scarcely
 perceptible1 and so is of no  practical
 importance4 ,their aerial life1 on the 

other hand1 in which  they respire and  
accomplish their process of oxidation   
under the  influence of free oxygen1 is 
a normal phenomenon1 and one of         
prolonged  duration which cannot fail to
 strike the least thoughtful of         
observers4  ,we are convinced that a day
 will come when moulds will be utilized 
in  certain industrial operations1 on   
account of their power of destroying    
organic matter4 ,the conversion of      
alcohol into vinegar in the process of  
acetification1 and the production of    
gallic acid by the action of fungi  on  
wet gall-nuts1 are already connected    
with this kind of  phenomena4#abb ,on   
this last subject1 the important work of
 ,m4 ,van  ,tieghem 7,annales           
,scientifiques de l'cole ,normale1 vol4 
vi47 may be  consulted4    ,the         
possibility of living without oxygen1 in
 the case of ordinary  moulds1 is       
connected with certain morphological    
modifications which are  more marked in 
proportion as this faculty is itself    

more developed4  ,these changes in the  
vegetative forms are scarcely           
perceptible in the  case of penicillium 
and mycoderma vini1 but they are very   
evident in  the case of aspergillus1    
consisting of a marked tendency on the  
part  of the submerged mycelial         
filaments to increase in diameter1 and  
to  develop cross partitions at short   
intervals1 so that they sometimes bear  
a resemblance to chains of conidia4 ,in 
mucor1 again1 they are very  marked1 the
 inflated filaments which1 closely      
interwoven1 present chains  of cells    
which fall off and bud1 gradually       
producing a mass of cells4 ,if  we      
consider the matter carefully1 we shall 
see that yeast presents the  same       
characteristics4 ,for instance1 what can
 more closely resemble the  mucor of    
,plates ,v4 and ,,vi4 than the          
saccharomyces of ,figs4 #cc and #cg8    
,have we not in each case ramified      
chains of elongated cells or joints1    
more or less narrowed in the middle1 and

 shorter segments or cells  dropping off
 at the constrictions1 and proceeding to
 bud in the liquid  on their own        
account8 ,moreover1 the less oxygen     
there is present1 the  more marked is   
the tendency to the formation of these  
budding cells1  which isolate themselves
 and soon drop off4 ,who could ever     
imagine1 in  examining the ferment of   
mucor represented in ,plate ,,vi41 that 
its  first germ was the ordinary mucor  
that is found everywhere1 with fine     
filaments1 straight or ramified         
according to the variety1 which send up 
aerial hyphae1 terminating in little    
round heads bearing spores4 ,so  was it 
that in the ferment of ,plate ,,xi4 we  
could scarcely recognize the  ramified  
filaments of ,figs4 #cc and #cg4    ,it 
is a great presumption in favour of the 
truth of theoretical ideas  when the    
results of experiments undertaken on the
 strength of those  ideas are confirmed 
by various facts more recently added to 
science1 and  when those ideas force    

themselves more and more on our minds1  
in spite  of a prim facie improbability4
 ,this is exactly the character of those
  ideas which we have just expounded4   
,we propounded them in #ahfa1 and not   
only have they remained unshaken since1 
but they have served to  foreshadow new 
facts1 so that it is much easier to     
defend them in the  present day than it 
was to do so fifteen years ago4 ,we     
first called  attention to them in      
various notes1 which we read before the 
,chemical  ,society of ,paris1 notably  
at its meetings of ,april #abth and     
,june #bhth1  #ahfa1 and in papers in   
the ,comptes rendus de l',acadmie des   
,sciences4  ,it may be of some interest 
to quote here1 in its entirety1 our     
communication of ,june #bhth1 #ahfa1    
entitled1 8,influences of ,oxygen on the
  ,development of ,yeast and on         
,alcoholic ,fermentation10 which we     
extract  from the ,bulletin de la ,socit
 ,chimique de ,paris3--    8,m4 ,pasteur
 gives the results of his researches on 

the fermentation of  sugar and the      
development of yeast-cells1 according as
 that fermentation  takes place apart   
from the influence of free oxygen or in 
contact with  that gas4 ,his            
experiments1 however1 have nothing in   
common with those of  ,gay-,lussac1     
which were performed with the juice of  
grapes1 crushed under  conditions where 
they would not be affected by air1 and  
then brought in  contact with oxygen4   
8,yeast1 when perfectly developed1 is   
able to bud and grow in a  saccharine   
and albuminous liquid1 in the complete  
absence of oxygen or  air4 ,in this case
 but little yeast is formed1 and a      
comparatively large  quantity of sugar  
disappears--sixty or eighty parts for   
one of yeast  formed4 ,under these      
conditions fermentation is very         
sluggish4    8,if the experiment is made
 in contact with the air1 and with a    
great  surface of liquid1 fermentation  
is rapid4 ,for the same quantity of     
sugar  decomposed much more yeast is    

formed4 ,the air with which the liquid  
is  in contact is absorbed by the yeast4
 ,the yeast develops very actively1  but
 its fermentative character tends to    
disappear under these  conditions2 we   
find1 in fact1 that for one part of     
yeast formed1 not  more than from four  
to ten parts of sugar are transformed4  
,the  fermentative character of this    
yeast1 nevertheless1 continues1 and     
produces even increased effects1 if it  
is made to act on sugar apart  from the 
influence of free oxygen4    8,it seems1
 therefore1 natural to admit that when  
yeast functions as a  ferment by living 
apart from the influence of air1 it     
derives oxygen  from the sugar1 and that
 this is the origin of its fermentative 
character4    8,m4 ,pasteur explains the
 fact of the immense activity at the    
commencement of fermentations by the    
influence of the oxygen of the air  held
 in solution in the liquids1 at the time
 when the action commences4  ,the author
 has found1 moreover1 that the yeast of 

beer sown in an  albuminous liquid1 such
 as yeast-water1 still multiplies1 even 
when  there is not a trace of sugar in  
the liquid1 provided always that        
atmospheric oxygen is present in large  
quantities4 ,when deprived of air1      
under these conditions1 yeast does not  
germinate at all4 ,the same  experiments
 may be repeated with albuminous liquid1
 mixed with a  solution of              
non-fermentable sugar1 such as ordinary 
crystallized  milk-sugar4 ,the results  
are precisely the same4    8,yeast      
formed thus in the absence of sugar does
 not change its nature2  it is still    
capable of causing sugar to ferment1 if 
brought to bear upon  that substance    
apart from air4 ,it must be remarked1   
however1 that the  development of yeast 
is effected with great difficulty when  
it has not a  fermentable substance for 
its food4 ,in short1 the yeast of beer  
acts in  exactly the same manner as an  
ordinary plant1 and the analogy would be
  complete if ordinary plants had such  

an affinity for oxygen as permitted     
them to breathe by appropriating this   
element from unstable compounds1  in    
which case1 according to ,m4 ,pasteur1  
they would appear as ferments  for those
 substances4    8,m4 ,pasteur declares  
that he hopes to be able to realize this
 result1  that is to say1 to discover   
the conditions under which certain      
inferior  plants may live apart from air
 in the presence of sugar1 causing that 
substance to ferment as the yeast of    
beer would do40    ,this summary and the
 preconceived views that it set forth   
have lost  nothing of their exactness2  
on the contrary1 time has strengthened  
them4  ,the surmises of the last two    
paragraphs have received a valuable     
confirmation from recent observations   
made by ,messrs4 ,lechartier and        
,bellamy1 as well as by ourselves1 an   
account of which we must put before  our
 readers4 ,it is necessary1 however1    
before touching upon this curious       
feature in connection with fermentations

 to insist on the accuracy of a  passage
 in the preceding summary1 the          
statement1 namely1 that yeast  could    
multiply in an albuminous liquid1 in    
which it found a  non-fermentable sugar1
 milk-sugar for example4 ,the following 
is an  experiment on this point3--,on   
,august #aeth1 #ahge1 we sowed a trace  
of  yeast in #aej c4c4 7rather more than
 #e fluid ounces7 of yeast-water1       
containing #b- per cent4 of milk-sugar4 
,the solution was prepared in one  of   
our double-necked flasks1 with the      
necessary precautions to secure  absence
 of germs1 and the yeast sown was itself
 perfectly pure4 ,three  months         
afterwards1 ,november #aeth1 #ahge1 we  
examined the liquid for  alcohol2 it    
contained only the smallest trace2 as   
for the yeast1 which  had sensibly      
developed1 collected and dried on a     
filter paper1 it  weighed #jjej gramme  
7#jgf grain74 ,in this case we have the 
yeast  multiplying without giving rise  
to the least fermentation1 like a       

fungoid growth1 absorbing oxygen1 and   
evolving carbonic acid1 and there  is no
 doubt that the cessation of its        
development in this experiment was  due 
to the progressive deprivation of oxygen
 that occurred4 ,as soon as  the gaseous
 mixture in the flask consisted entirely
 of carbonic acid and  nitrogen1 the    
vitality of the yeast was dependent on1 
and in proportion  to1 the quantity of  
air which entered the flask in          
consequence of  variations of           
temperature4 ,the question now arose1   
was this yeast1 which  had developed    
wholly as an ordinary fungus1 still     
capable of manifesting  the character of
 a ferment8 ,to settle this point we had
 taken the  precaution1 on ,august      
#aeth1 #ahge1 of preparing another      
flask1 exactly  similar to the preceding
 one in every respect1 and which gave   
results  identical with those described4
 ,we decanted this on ,november #aeth1  
pouring some wort on the deposit of the 
plant1 which remained in the  flask4 ,in

 less than five hours from the time when
 we placed it in the  oven1 the plant   
had started fermentation in the wort1 as
 we could see by  the bubbles of gas    
rising to form patches on the surface of
 the liquid4  ,we may add that yeast in 
the medium which we have been discussing
 will  not develop at all without air4  
,the importance of these results can    
escape no one2 they prove clearly  that 
the fermentative character is not an    
invariable phenomenon of  yeast-life1   
they show that yeast is a plant which   
does not differ from  ordinary plants1  
and which manifests its fermentative    
power solely in  consequence of         
particular conditions under which it is 
compelled to  live4 ,it may carry on its
 life as a ferment or not1 and after    
having  lived without manifesting the   
slightest symptom of fermentative       
character1 it is quite ready to manifest
 that character when brought  under     
suitable conditions4 ,the fermentative  
property1 therefore1 is not  a power    

peculiar to cells of a special nature4  
,it is not a permanent  character of a  
particular structure1 like1 for         
instance1 the property of  acidity or   
alkalinity4 ,it is a peculiarity        
dependent on external  circumstances and
 on the nutritive conditions of the     
organism4        ,,ii4--,fermentation in
 ,saccharine ,fruits ,immersed in       
,carbonic ,acid ,gas4      ,the theory  
which we have1 step by step1 evolved1 on
 the subject of the  causes of the      
chemical phenomena of fermentation1 may 
claim a character  of simplicity and    
generality that is well worthy of       
attention4  ,fermentation is no longer  
one of those isolated and mysterious    
phenomena  which do not admit of        
explanation4 ,it is the consequence of a
 peculiar  vital process of nutrition   
which occurs under certain conditions1  
differing from those which characterize 
the life of all ordinary beings1  animal
 or vegetable1 but by which the latter  
may be affected1 more or  less1 in a way

 which brings them1 to some extent4     
within the class of  ferments1 properly 
so called4 ,we can even conceive that   
the fermentative  character may belong  
to every organized form1 to every animal
 or  vegetable cell1 on the sole        
condition that the chemico-vital acts of
  assimilation and excretion must be    
capable of taking place in that cell    
for a brief period1 longer or shorter it
 may be1 without the necessity  for     
recourse to supplies of atmospheric     
oxygen2 in other words1 the cell  must  
be able to derive its needful heat from 
the decomposition of some  body which   
yields a surplus of heat in the process4
    ,as a consequence of these          
conclusions it should be an easy matter 
to  show1 in the majority of living     
beings1 the manifestation of the        
phenomena of fermentation2 for there    
are1 probably1 none in which all        
chemical action entirely disappears1    
upon the sudden cessation of life4  ,one
 day1 when we were expressing these     

views in our laboratory1 in the         
presence of ,m4 ,dumas1 who seemed      
inclined to admit their truth1 we       
added3 8,we would make a wager that if  
we were to plunge a bunch of  grapes    
into carbonic acid gas1 there would be  
immediately produced  alcohol and       
carbonic acid1 in consequence of a      
renewed action starting  in the interior
 cells of the grapes1 in such a way that
 these cells  would assume the function 
of yeast-cells4 ,we will make the       
experiment1  and when you come          
to-morrow--it was our good fortune to   
have ,m4 ,dumas  working in our         
laboratory at that time--we will give   
you an account of  the result40 ,our    
predictions were realized4 ,we then     
endeavoured to find1  in the presence of
 ,m4 ,dumas1 who assisted us in our     
endeavour1 cells of  yeast in the       
grapes2 but it was quite impossible to  
discover any4#abc    ,encouraged by this
 result1 we undertook fresh experiments 
on grapes1 on  a melon1 on oranges1 on  

plums1 and on rhubarb leaves1 gathered  
in the  garden of the cole ,normale1    
and1 in every case1 our substance when  
immersed in carbonic acid gas1 gave rise
 to the production of alcohol  and      
carbonic acid4 ,we obtained the         
following surprising results from  some 
prunes de ,monsieur#abd3--,on ,july     
#cast1 #ahgb1 we placed  twenty-four of 
these plums under a glass cylinder1     
which we immediately  filled with       
carbonic acid gas4 ,the plums had been  
gathered on the  previous day4 ,by the  
side of the cylinder we placed other    
twenty-four  plums1 which were left     
there uncovered4 ,eight days afterwards1
 in the  course of which time there had 
been a considerable evolution of        
carbonic  acid from the cylinder1 we    
withdrew the plums and compared them    
with  those which had been left exposed 
to the air4 ,the difference was         
striking1 almost incredible4 ,whilst the
 plums which had been surrounded  with  
air 7the experiments of ,brard have long

 since taught us that1  under this      
latter condition1 fruits absorb oxygen  
from the air and emit  carbonic acid gas
 in almost equal volume7 had become very
 soft and  watery and sweet1 the plums  
taken from under the jar had remained   
very  firm and hard1 the flesh was by no
 means watery1 but they had lost much   
sugar4 ,lastly1 when submitted to       
distillation1 after crushing1 they      
yielded #fe grammes 7#iig grains7 of    
alcohol1 more than #a per cent4 of  the 
total weight of the plums4 ,what better 
proof could we have than  these facts of
 the existence of a considerable        
chemical action in the  interior of     
fruit1 an action which derives the heat 
necessary for its  manifestation from   
the decomposition of the sugar present  
in the cells8  ,moreover1 and this      
circumstance is especially worthy of our
 attention1  in all these experiments we
 found that there was a liberation of   
heat1  of which the fruits and other    
organs were the seat1 as soon as they   

were  plunged in the carbonic acid gas4 
,this heat is so considerable that it   
may at times be detected by the hand1 if
 the two sides of the cylinder1  one of 
which is in contact with the objects1   
are touched alternately4 ,it  also makes
 itself evident in the formation of     
vapour1 which condenses in  little drops
 on those parts of the bell which are   
less directly exposed  to the influence 
of the heat resulting from the          
decomposition of the  sugar of the      
cells4#abe    ,in short1 fermentation is
 a very general phenomenon4 ,it is life 
without  air1 or life without free      
oxygen1 or1 more generally still1 it is 
the  result of a chemical process       
accomplished on a fermentable substance1
  i4e4 a substance capable of producing 
heat by its decomposition1 in  which    
process the entire heat used up is      
derived from a part of the heat  that   
the decomposition of the fermentable    
substance sets free4 ,the class  of     
fermentations1 properly so called1 is1  

however1 restricted by the  small number
 of substances capable of decomposing   
with the production of  heat1 and at the
 same time of serving for the           
nourishment of lower forms  of life1    
when deprived of the presence and action
 of air4 ,this1 again1  is a consequence
 of our theory1 which is well worthy of 
notice4    ,the facts that we have just 
mentioned in reference to the formation 
of  alcohol and carbonic acid in the    
substance of ripe fruits1 under certain 
special conditions1 and apart from the  
action of ferment1 are already  known to
 science4 ,they were discovered in #ahfi
 by ,m4 ,lechartier1  formerly a pupil  
in the cole ,normale ,suprieure1 and his
 coadjutor1  ,m4 ,bellamy4#abf ,in      
#ahba1 in a very remarkable work1       
especially when we  consider the period 
when it appeared1 ,brard demonstrated   
several  important propositions in      
connection with the maturation of       
fruits3--    ,i4 ,all fruits1 even those
 that are still green1 and likewise even

 those  that are exposed to the sun1    
absorb oxygen and set free an almost    
equal  volume of carbonic acid gas4     
,this is a condition of their proper    
ripening4    ,,ii4 ,ripe fruits placed  
in a limited atmosphere1 after having   
absorbed  all the oxygen and set free an
 almost equal volume of carbonic acid1  
continue to emit that gas in notable    
quantity1 even when no bruise is to  be 
seen--8as though by a kind of           
fermentation10 as ,brard actually       
observes--and lose their saccharine     
particles1 a circumstance which  causes 
the fruits to appear more acid1 although
 the actual weight of  their acid may   
undergo no augmentation whatever4    ,in
 this beautiful work1 and in all        
subsequent ones of which the ripening   
of fruits has been the subject1 two     
facts of great theoretical value  have  
escaped the notice of the authors2 these
 are the two facts which  ,messrs4      
,lechartier and ,bellamy pointed out1   
for the first time1 namely1  the        

production of alcohol and the absence of
 cells of ferments4 ,it is  worthy of   
remark that these two facts1 as we have 
shown above1 were  actually foreshadowed
 in the theory of fermentation that we  
advocated as  far back as #ahfa1 and we 
are happy to add that ,messrs4          
,lechartier and  ,bellamy1 who1 at      
first1 had prudently drawn no           
theoretical conclusions  from their     
work1 now entirely agree with the theory
 we have  advanced4#abg ,their mode of  
reasoning is very different from that of
  the savants with whom we discussed the
 subject before the ,academy1 on  the   
occasion when the communication which we
 addressed to the ,academy1  in         
,october1 #ahgb1 attracted attention    
once more to the remarkable             
observations of ,messrs4 ,lechartier and
 ,bellamy4#abh ,m4 ,fremy1 in           
particular1 was desirous of finding in  
those observations a confirmation  of   
his views on the subject of             
hemi-organism1 and a condemnation of    

ours1 notwithstanding the fact that the 
preceding explanations and1 more        
particularly our ,note of #ahfa1 which  
we have quoted word for word in the     
last paragraph1 furnish the most        
conclusive evidence in favour of those  
ideas which we advocate4 ,indeed1 as far
 back as #ahfa we pointed out very      
clearly that if we could find plants    
able to live when deprived of air1  in  
the presence of sugar1 they would bring 
about a fermentation of that  substance1
 in the same manner as yeast does4 ,such
 is the case with the  fungi already    
studied in ,chapter ,,iv42 such1 too1 is
 the case with the  fruits employed in  
the experiments of ,messrs4 ,lechartier 
and ,bellamy1  and in our own           
experiments1 the results of which not   
only confirm those  obtained by these   
gentlemen1 but even extend them1 in so  
far as we have  shown that fruits1 when 
surrounded with carbonic acid gas1      
immediately  produce alcohol4 ,when     
surrounded with air1 they live in their 

arobian  state1 and we have no          
ferment-action2 immersed immediately    
afterwards in  carbonic acid gas1 they  
now assume their anarobian state1 and at
 once  begin to act upon the sugar in   
the manner of ferments1 and emit heat4  
,as  for seeing in these facts anything 
like a confirmation of the theory of    
hemi-organism1 imagined by ,m4 ,fremy1  
the idea of such a thing is absurd4     
,the following1 for instance1 is the    
theory of the fermentation of the       
vintage1 according to ,m4 ,fremy4#abi   
8,to speak here of alcoholic            
fermentation alone10#acj our author     
says1  8,i hold that in the production  
of wine it is the juice of the fruit    
itself that1 in contact with air1       
produces grains of ferment1 by the      
transformation of the albuminous matter2
 ,m4 ,pasteur1 on the other hand1       
maintains that the fermentation is      
produced by germs existing outside  the 
skin of the grapes40    ,now what       
bearing on this purely imaginary theory 

can the fact have1 that  a whole fruit1 
immersed in carbonic acid gas1          
immediately produces  alcohol and       
carbonic acid8 ,in the preceding        
passage1 which we have  borrowed from   
,m4 ,fremy1 an indispensable condition  
of the transformation  of the albuminous
 matter is the contact with air and the 
crushing of the  grapes4 ,here1 however1
 we are dealing with uninjured fruits in
 contact  with carbonic acid gas4 ,our  
theory1 on the other hand1 which1 we may
  repeat1 we have advocated since #ahfa1
 maintains that all cells become        
fermentative when their vital action is 
protracted in the absence of  air1 which
 are precisely the conditions that hold 
in the experiment on  fruits immersed in
 carbonic acid gas4 ,the vital energy is
 not  immediately suspended in their    
cells1 and the latter are deprived of   
air4 ,consequently1 fermentation must   
result4 ,moreover1 we may add1 if we    
destroy the fruit1 or crush it before   
immersing it in the gas1 it no  longer  

produces alcohol or fermentation of any 
kind1 a circumstance that  may be       
attributed to the fact of the           
destruction of vital action in the      
crushed fruit4 ,on the other hand1 in   
what way ought this crushing to  affect 
the hypothesis of hemi-organism8 ,the   
crushed fruit ought to act  quite as    
well1 or even better than that which is 
uncrushed4 ,in short1  nothing can be   
more directly opposed to the theory of  
the mode of  manifestation of that      
hidden force to which the name of       
hemi-organism  has been given1 than the 
discovery of the production of these    
phenomena  of fermentation in fruits    
surrounded with carbonic acid gas2      
whilst the  theory1 which sees in       
fermentation a consequence of vital     
energy in  absence of air1 finds in     
these facts the strictest confirmation  
of an  express prediction1 which from   
the first formed an integral part of its
  statement4    ,we should not be       
justified in devoting further time to   

opinions which  are not supported by any
 serious experiment4 ,abroad1 as well as
 in  ,france1 the theory of the         
transformation of albuminous substances 
into  organized ferments had been       
advocated long before it was taken up by
 ,m4  ,fremy4 ,it no longer commands the
 slightest credit1 nor do any observers 
of note any longer give it the least    
attention2 it might even be said  that  
it has become a subject of ridicule4    
,an attempt has also been made to prove 
that we have contradicted  ourselves1   
inasmuch as in #ahfj we published our   
opinion that alcoholic  fermentation can
 never occur without a simultaneous     
occurrence of  organization1            
development1 and multiplication of      
globules2 or continued  life1 carried on
 from globules already formed4#aca      
,nothing1 however1  can be truer than   
that opinion1 and at the present moment1
 after fifteen  years of study devoted  
to the subject1 since the publication to
 which we  have referred1 we need no    

longer say 8we think10 but instead1 8we 
affirm0 that it is correct4 ,it is1 as a
 matter of fact1 to alcoholic           
fermentation1 properly so called1 that  
the charge to which we have  referred   
relates--to that fermentation which     
yields1 besides alcohol1  carbonic acid1
 succinic acid1 glycerine1 volatile     
acids1 and other  products4 ,this       
fermentation undoubtedly requires the   
presence of  yeast-cells1 under the     
conditions that we have named4 ,those   
who have  contradicted us have fallen   
into the error of supposing that the    
fermentation of fruits is an ordinary   
alcoholic fermentation1 identical  with 
that produced by beer-yeast1 and that1  
consequently1 the cells of  that yeast  
must1 according to our own theory1 be   
always present4 ,there  is not the least
 authority for such a supposition4 ,when
 we come to exact  quantitative         
estimations--and these are to be found  
in the figures  supplied by ,messrs4    
,lechartier and ,bellamy--it will be    

seen that the  proportions of alcohol   
and carbonic acid gas produced in the   
fermentation of fruits differ widely    
from those that we find in  alcoholic   
fermentations1 properly so called1 as   
must necessarily be the  case1 since1 in
 the former1 the ferment-action is      
effected by the cells  of a fruit1 but  
in the latter by cells of ordinary      
alcoholic ferment4  ,indeed we have a   
strong conviction that each fruit would 
be found to  give rise to a special     
action1 the chemical equation of which  
would be  different from that in the    
case of other fruits4 ,as for the       
circumstance  that the cells of these   
fruits cause fermentation1 without      
multiplying1  this comes under the kind 
of activity1 which we have already      
distinguished by the expression         
continuous life in cells already        
formed4    ,we will conclude this       
paragraph with a few remarks on the     
subject of the  equations of            
fermentations1 which have been suggested

 to us principally  in attempts to      
explain the results derived from the    
fermentation of  fruits immersed in     
carbonic acid gas4    ,originally1 when 
fermentations were put amongst the class
 of  decompositions by contact-action1  
it seemed probable1 and1 in fact1 was   
believed1 that every fermentation had   
its own well-defined equation1  which   
never varied4 ,in the present day1 on   
the contrary1 it must be  borne in mind 
that the equation of a fermentation     
varies essentially  with the conditions 
under which that fermentation is        
accomplished1 and  that a statement of  
this equation is a problem no less      
complicated than  that in the case of   
the nutrition of a living being4 ,to    
every  fermentation may be assigned an  
equation in a general sort of way1 an   
equation1 however1 which1 in numerous   
points of detail1 is liable to the      
thousand variations connected with the  
phenomena of life4 ,moreover1  there    
will be as many distinct fermentations  

brought about by one  ferment as there  
are fermentable substances capable of   
supplying the  carbon element of the    
food of that same ferment1 in the same  
way that  the equation of the nutrition 
of an animal will vary with the nature  
of  the food which it consumes4 ,as     
regards fermentation producing alcohol1 
which may be effected by several        
different ferments1 there will be1 in   
the case of a given sugar1 as many      
general equations as there are          
ferments1 whether they be ferment-cells1
 properly so called1 or cells of  the   
organs of living beings functioning as  
ferments4 ,in the same way the  equation
 of nutrition varies in the case of     
different animals nourished  on the same
 food4 ,and it is from the same reason  
that ordinary wort  produces such a     
variety of beers when treated with the  
numerous  alcoholic ferments which we   
have described4 ,these remarks are      
applicable  to all ferments alike2 for  
instance1 butyric ferment is capable of 

producing a host of distinct            
fermentations1 in consequence of its    
ability to derive the carbonaceous part 
of its food from very different         
substances1 from sugar1 or lactic acid1 
or glycerine1 or mannite1 and  many     
others4    ,when we say that every      
fermentation has its own peculiar       
ferment1 it  must be understood that we 
are speaking of the fermentation        
considered  as a whole1 including all   
the accessory products4 ,we do not mean 
to  imply that the ferment in question  
is not capable of acting on some  other 
fermentable substance and giving rise to
 fermentation of a very  different kind4
 ,moreover1 it is quite erroneous to    
suppose that the  presence of a single  
one of the products of a fermentation   
implies the  co-existence of a          
particular ferment4 ,if1 for example1 we
 find alcohol  among the products of a  
fermentation1 or even alcohol and       
carbonic acid  gas together1 this does  
not prove that the ferment must be an   

alcoholic  ferment1 belonging to        
alcoholic fermentations1 in the strict  
sense of  the term4 ,nor1 again1 does   
the mere presence of lactic acid        
necessarily  imply the presence of      
lactic ferment4 ,as a matter of fact1   
different  fermentations may give rise  
to one or even several identical        
products4  ,we could not say with       
certainty1 from a purely chemical point 
of view1  that we were dealing1 for     
example1 with an alcoholic fermentation1
  properly so called1 and that the yeast
 of beer must be present in it1 if  we  
had not first determined the presence of
 all the numerous products of  that     
particular fermentation1 and that they  
were present in those  proportions1     
characteristic of that fermentation     
under conditions  similar to those under
 which the fermentation in question had 
occurred4  ,in works on fermentation1   
the reader will often find those        
confusions  against which we are now    
attempting to guard him4 ,it is         

precisely in  consequence of not having 
had their attention drawn to such       
observations  that some have imagined   
that the fermentation in fruits1        
immersed in  carbonic acid gas1 is in   
contradiction to the assertion which we 
originally made in our ,memoir on       
alcoholic fermentation1 published in    
#ahfj1 the exact words of which we may  
here repeat3--8,the chemical  phenomena 
of fermentation are related essentially 
to a vital activity1  beginning and     
ending with the latter2 we believe that 
alcoholic  fermentation never           
occurs0--we were discussing the question
 of ordinary  alcoholic fermentation    
produced by the yeast of beer--8without 
the  simultaneous occurrence of         
organization1 development1 and          
multiplication  of globules1 or         
continued life1 carried on by means of  
globules already  formed4 ,the general  
results of the present ,memoir seem to  
us to be in  direct opposition to the   
opinions of ,,mm4 ,liebig and           

,berzelius40 ,these  conclusions1 we    
repeat1 are as true now as they ever    
were1 and are as  applicable to the     
fermentation of fruits1 of which nothing
 was known in  #ahfj1 as they are to the
 fermentation produced by means of      
yeast4 ,only1  in the case of fruits1 it
 is the cells of the parenchyma that    
function  as ferment1 by a continuation 
of their vital activity in carbonic acid
  gas1 whilst in the other case the     
ferment consists of the cells of  yeast4
    ,there should be nothing very       
surprising in the fact that fermentation
  can originate in fruits and form      
alcohol1 without the presence of yeast1 
if the fermentation of fruits were not  
confounded completely with  ordinary    
alcoholic fermentation1 yielding the    
same products and in the  same          
proportions4 ,it is through the misuse  
of words that the  fermentation of      
fruits has been termed alcoholic1 in a  
way which has  misled many persons4#acb 
,in this fermentation1 neither alcohol  

nor  carbonic acid gas exists in those  
proportions in which they are found in  
fermentations produced by yeast2 and    
although we may determine in it the     
presence of succinic acid1 glycerine1   
and a small quantity of volatile        
acids1#acc the relative proportions of  
these substances will be  different from
 what they are in the case of alcoholic 
fermentation4       ,,iii4--,reply to   
certain ,critical ,observations of the  
,german ,naturalists1                   
,oscar ,brefeld and ,moritz ,traube4    
,the essential point of the theory of   
fermentation1 which we have been        
concerned in proving in preceding       
paragraphs1 may be briefly put in the   
statement that ferments1 properly so    
called1 constitute a class of  beings   
possessing the faculty of living out of 
contact with free oxygen2  or1 more     
concisely still1 we may say1            
fermentation is a result of life        
without air4    ,if our affirmation were
 inexact1 if ferment-cells did require  

for their  growth or for their increase 
in number or weight1 as all other       
vegetable  cells do1 the presence of    
oxygen1 whether gaseous or held in      
solution in  liquids1 this new theory   
would lose all value1 its very raison   
d'tre  would be gone1 at least as far as
 the most important part of             
fermentations is concerned4 ,this is    
precisely what ,m4 ,oscar ,brefeld has  
endeavoured to prove1 in a ,memoir read 
to the ,physico-,medical ,society of    
,wurzburg1 on ,july #bfth1 #ahgc1 in    
which1 although we have ample evidence  
of the great experimental skill of its  
author1 he has1 nevertheless1 in  our   
opinion1 arrived at conclusions entirely
 opposed to fact4    8,from the         
experiments which ,i have just          
described10 he says1 8it  follows1 in   
the most indisputable manner1 that a    
ferment cannot  increase without free   
oxygen4 ,pasteur's supposition that a   
ferment1  unlike all other living       
organisms1 can live and increase at the 

expense  of oxygen held in combination1 
is1 consequently1 altogether wanting in 
any solid basis of experimental proof4  
,moreover1 since1 according to the      
theory of ,pasteur1 it is precisely this
 faculty of living and increasing  at   
the expense of the oxygen held in       
combination that constitutes the        
phenomenon of fermentation1 it follows  
that the whole theory1 commanding       
though it does such general assent1 is  
shown to be untenable2 it is  simply    
inaccurate40    ,the experiments to     
which ,dr4 ,brefeld alludes1 consisted  
in keeping under  continued study with  
the microscope1 in a room specially     
prepared for  the purpose1 one or more  
cells of ferment in wort1 in an         
atmosphere of  carbonic acid gas1 free  
from the least traces of free oxygen4   
,we have1  however1 recognized the fact 
that the increase of a ferment out of   
contact with air is only possible in the
 case of a very young specimen2  but our
 author employed brewer's yeast taken   

after fermentation1 and to  this fact we
 may attribute the non-success of his   
growths4 ,dr4 ,brefeld1  without knowing
 it1 operated on yeast in one of the    
states in which it  requires gaseous    
oxygen to enable it to germinate again4 
,a perusal of  what we have previously  
written on the subject of the revival of
 yeast1  according to its age1 will show
 how widely the time required for such  
revival may vary in different cases4    
,what may be perfectly true of the      
state of a yeast to-day may not be so   
to-morrow1 since yeast is  continually  
undergoing modifications4 ,we have      
already shown the energy  and activity  
with which a ferment can vegetate in the
 presence of free  oxygen1 and we have  
pointed out the great extent to which a 
very small  quantity of oxygen held in  
solution in fermenting liquids can      
operate at  the beginning of            
fermentation4 ,it is this oxygen that   
produces revival  in the cells of the   
ferment and enables them to resume the  

faculty of  germinating and continuing  
their life1 and of multiplying when     
deprived  of air4    ,in our opinion1 a 
simple reflection should have guarded   
,dr4 ,brefeld  against the              
interpretation which he has attached to 
his observations4 ,if  a cell of ferment
 cannot bud or increase without         
absorbing oxygen1  either free or held  
in solution in the liquid1 the ratio    
between the  weight of ferment formed   
during fermentation and that of oxygen  
used up  must be constant4 ,we had1     
however1 clearly established1 as far    
back as  #ahfa1 the fact that this ratio
 is extremely variable1 a fact1         
moreover1  which is placed beyond doubt 
by the experiments described in the     
preceding paragraph4 ,though but small  
quantities of oxygen are absorbed1  a   
considerable weight of ferment may be   
generated2 whilst if the ferment  has   
abundance of oxygen at its disposal1 it 
will absorb much1 and the  weight of    
yeast formed will be still greater4 ,the

 ratio between the  weight of ferment   
formed and that of sugar decomposed may 
pass through  all stages between certain
 very wide limits1 the variations       
depending on  the greater or less       
absorption of free oxygen4 ,and in this 
fact1 we  believe1 lies one of the most 
essential supports of the theory which  
we  advocate4 ,in denouncing the        
impossibility1 as he considered it1 of a
  ferment living without air or oxygen1 
and so acting in defiance of that  law  
which governs all living beings1 animal 
or vegetable1 ,dr4 ,brefeld  ought also 
to have borne in mind the fact which we 
have pointed out1  that alcoholic yeast 
is not the only organized ferment which 
lives in an  anarobian state4 ,it is    
really a small matter that one more     
ferment  should be placed in a list of  
exceptions to the generality of living  
beings1 for whom there is a rigid law in
 their vital economy which  requires for
 continued life a continuous            
respiration1 a continuous  supply of    

free oxygen4 ,why1 for instance1 has    
,dr4 ,brefeld omitted the  facts bearing
 on the life of the vibrios of butyric  
fermentation8  ,doubtless he thought we 
were equally mistaken in these3 a few   
actual  experiments would have put him  
right4    ,these remarks on the         
criticisms of ,dr4 ,brefeld are also    
applicable to  certain observations of  
,m4 ,moritz ,traube's1 although1 as     
regards the  principal object of ,dr4   
,brefeld's attack1 we are indebted to   
,m4 ,traube  for our defence4 ,this     
gentleman maintained the exactness of   
our results  before the ,chemical       
,society of ,berlin1 proving by fresh   
experiments that  yeast is able to live 
and multiply without the intervention of
 oxygen4  8,my researches10 he said1    
8confirm in an indisputable manner ,m4  
,pasteur's assertion that the           
multiplication of yeast can take place  
in  media which contain no trace of free
 oxygen4444 ,m4 ,brefeld's assertion  to
 the contrary is erroneous40 ,but1      

immediately afterwards1 ,m4 ,traube     
adds3 8,have we here a confirmation of  
,pasteur's theory8 ,by no means4 ,the   
results of my experiments demonstrate1  
on the contrary1 that this theory  has  
no sure foundation40 ,what were these   
results8 ,whilst proving that  yeast    
could live without air1 ,m4 ,traube1 as 
we ourselves did1 found that  it had    
great difficulty in living under these  
conditions2 indeed he  never succeeded  
in obtaining more than the first stages 
of true  fermentation4 ,this was        
doubtless for the two following         
reasons--first1 in  consequence of the  
accidental production of secondary and  
diseased  fermentations1 which          
frequently prevent the propagation of   
alcoholic  ferment2 and1 secondly1 in   
consequence of the original exhausted   
condition of the yeast employed4 ,as    
long ago as #ahfa we pointed out the    
slowness and difficulty of the vital    
action of yeast when deprived of  air1  
and a little way back1 in the preceding 

paragraph1 we have called  attention to 
certain fermentations that cannot be    
completed under such  conditions without
 going into the causes of these         
peculiarities4 ,m4  ,traube expresses   
himself thus3 8,pasteur's conclusion1   
that yeast in the  absence of air is    
able to derive the oxygen necessary for 
its  development from sugar1 is         
erroneous2 its increase is arrested1    
even  when the greater part of the sugar
 still remains undecomposed4 ,it is in  
a mixture of albuminous substances that 
yeast1 when deprived of air1  finds the 
materials for its development40 ,this   
last assertion of ,m4  ,traube's is     
entirely disproved by those fermentation
 experiments in  which1 after           
suppressing the presence of albuminous  
substances1 the  action1 nevertheless1  
went on in a purely inorganic medium1   
out of  contact with air1 a fact of     
which we shall give irrefutable         
proofs4#acd                             
,,iv4--,fermentation of                 

,dextro-,tartrate of ,lime4#ace         
,tartrate of lime1 in spite of its      
insolubility in water1 is capable of    
complete fermentation in a mineral      
medium4    ,if we put some pure tartrate
 of lime1 in the form of a granulated1  
crystalline powder1 into pure water1    
together with some sulphate of  ammonia 
and phosphates of potassium and         
magnesium1 in very small  proportions1 a
 spontaneous fermentation will take     
place in the deposit  in the course of a
 few days1 although no germs of ferment 
have been  added4 ,a living1 organized  
ferment1 of the vibrionic type1         
filiform1  with tortuous motions1 and   
often of immense length1 forms          
spontaneously  by the development of    
some germs derived in some way from the 
inevitable  particles of dust floating  
in the air or resting on the surface of 
the  vessels or materials which we      
employ4 ,the germs of the vibrios       
concerned  in putrefaction are diffused 
around us on every side1 and1 in all    

probability1 it is one or more of these 
germs that develop in the medium  in    
question4 ,in this way they effect the  
decomposition of the tartrate1  from    
which they must necessarily obtain the  
carbon of their food1  without which    
they cannot exist1 while the nitrogen is
 furnished by the  ammonia of the       
ammoniacal salt1 the mineral principles 
by the phosphate  of potassium and      
magnesium1 and the sulphur by the       
sulphate of ammonia4  ,how strange to   
see organization1 life1 and motion      
originating under such  conditions6     
,stranger still to think that this      
organization1 life1 and  motion are     
effected without the participation of   
free oxygen4 ,once the  germ gets a     
primary impulse on its living career by 
access of oxygen1 it  goes on           
reproducing indefinitely1 absolutely    
without atmospheric air4  ,here then we 
have a fact which it is important to    
establish beyond the  possibility of    
doubt1 that we may prove that yeast is  

not the only  organized ferment able to 
live and multiply when out of the       
influence of  free oxygen4    ,into a   
flask1 like that represented in ,fig4   
#fg1 of #be litres 7about  four pints7  
in capacity1 we put3--                  
,pure1 crystallized1 neutral tartrate of
  #ajj grammes4           lime          
,phosphate of ammonia                   
#a gramme4             ,phosphate of    
magnesium                      #a       
gramme4             ,phosphate of       
potassium                    #je gramme4
             ,sulphate of ammonia       
#je gramme4             7#a gramme#aedc 
grains47    ,to this we added pure      
distilled water1 so as to entirely fill 
the flask4    ,in order to expel all the
 air dissolved in the water and adhering
 to the  solid substances1 we first     
placed our flask in a bath of chloride  
of  calcium1 in a large cylindrical     
white iron pot1 set over a flame4 ,the  
exit-tube of the flask was plunged in a 
test-tube of ,bohemian glass            

three-quarters full of distilled water1 
and also heated by a flame4 ,we  boiled 
the liquids in the flask and test-tube  
for a sufficient time to  expel all the 
air contained in them4 ,we then withdrew
 the heat from  under the test-tube1 and
 immediately afterwards covered the     
water which  it contained with a layer  
of oil1 and then permitted the whole    
apparatus  to cool down4                
,illustration3 ,fig4 #fg4    ,next day  
we applied a finger to the open         
extremity of the exit-tube1  which we   
then plunged in a vessel of mercury4 ,in
 this particular  experiment which we   
are describing1 we permitted the flask  
to remain in  this state for a          
fortnight4 ,it might have remained for a
 century without  ever manifesting the  
least sign of fermentation1 the         
fermentation of the  tartrate being a   
consequence of life1 and life after the 
boiling no  longer existed in the flask4
 ,when it was evident that the contents 
of  the flask were perfectly inert1 we  

impregnated them rapidly1 as            
follows3--,all the liquid contained in  
the exit-tube was removed by means  of a
 fine caoutchouc tube1 and replaced by  
about #a c4c4 7about #ag  minims7 of    
liquid and deposit from another flask1  
similar to the one we  have described1  
but which had been fermenting           
spontaneously for twelve  days2 we lost 
no time in refilling completely the     
exit-tube with water  which had been    
first boiled and then cooled down in    
carbonic acid gas4  ,this operation     
lasted only a few minutes4 ,the         
exit-tube was again  plunged under      
mercury4 ,subsequently the tube was not 
moved from under  the mercury1 and as it
 formed part of the flask1 and there was
 neither  cork nor india-rubber1 any    
introduction of air was consequently    
impossible4 ,the small quantity of air  
introduced during the impregnation  was 
insignificant1 and it might even be     
shown that it injured rather  than      
assisted the growth of the organisms1   

inasmuch as these consisted  of adult   
individuals which had lived without air 
and might be liable to  be damaged or   
even destroyed by it4 ,be this as it    
may1 in a subsequent  experiment we     
shall find the possibility removed of   
any aeration taking  place in this way1 
however infinitesimal1 so that no doubt 
may linger on  this subject4    ,the    
following days the organisms multiplied1
 the deposit of tartrate  gradually     
disappeared1 and a sensible ferment     
action was manifest on the  surface1 and
 throughout the bulk of the liquid4 ,the
 deposit seemed  lifted up in places1   
and was covered with a layer of a       
dark-grey colour1  puffed up1 and having
 an organic and gelatinous appearance4  
,for several  days1 in spite of this    
action in the deposit1 we detected no   
disengagement of gas1 except when the   
flask was slightly shaken1 in  which    
case rather large bubbles adhering to   
the deposit rose1 carrying  with them   
some solid particles1 which quickly fell

 back again1 whilst  the bubbles        
diminished in size as they rose1 from   
being partially taken  into solution1 in
 consequence of the liquid not being    
saturated4 ,the  smallest bubbles had   
even time to dissolve completely before 
they could  reach the surface of the    
liquid4 ,in course of time the liquid   
was  saturated1 and the tartrate was    
gradually displaced by mammillated      
crusts1 or clear1 transparent crystals  
of carbonate of lime at the  bottom and 
on the sides of the vessel4    ,the     
impregnation took place on ,february    
#ajth1 and on ,march #aeth the  liquid  
was nearly saturated4 ,the bubbles then 
began to lodge in the bent  part of the 
exit-tube1 at the top of the flask4 ,a  
glass measuring-tube  containing mercury
 was now placed with its open end over  
the point of  the exit-tube under the   
mercury in the trough1 so that no bubble
 might  escape4 ,a steady evolution of  
gas went on from the #agth to the #ahth1
  #agd c4c4 7#ajf cubic inches7 having  

been collected4 ,this was proved to  be 
nearly absolutely pure carbonic acid1 as
 indeed might have been  suspected from 
the fact that the evolution did not     
begin before a  distinct saturation of  
the liquid was observed4#acf    ,the    
liquid1 which was turbid on the day     
after its impregnation1 had1 in  spite  
of the liberation of gas1 again become  
so transparent that we  could read our  
handwriting through the body of the     
flask4  ,notwithstanding this1 there was
 still a very active operation going on 
in the deposit1 but it was confined to  
that spot4 ,indeed1 the swarming        
vibrios were bound to remain there1 the 
tartrate of lime being still  more      
insoluble in water saturated with       
carbonate of lime than it is in  pure   
water4 ,a supply of carbonaceous food1  
at all events1 was absolutely  wanting  
in the bulk of the liquid4 ,every day we
 continued to collect and  analyze the  
total amount of gas disengaged4 ,to the 
very last1 it was  composed of pure     

carbonic acid gas4 ,only during the     
first few days did  the absorption by   
the concentrated potash leave a very    
minute residue4  ,by ,april #bfth all   
liberation of gas had ceased1 the last  
bubbles having  risen in the course of  
,april #bcrd4 ,the flask had been all   
the time in  the oven1 at a temperature 
between #be ,c4 and #bh ,c4 7#gg ,f4 and
 #hc  ,f474 ,the total volume of gas    
collected was #bace litres 7#acjb cubic 
inches74 ,to obtain the whole volume of 
gas formed we had to add to this  what  
was held in the liquid in the state of  
acid carbonate of lime4 ,to  determine  
this we poured a portion of the liquid  
from the flask into  another flask of   
similar shape1 but smaller1 up to a     
gauge-mark on the  neck4#acg ,this      
smaller flask had been previously filled
 with carbonic  acid4 ,the carbonic acid
 of the fermented liquid was then       
expelled by  means of heat1 and         
collected over mercury4 ,in this way we 
found a volume  of #hcbb litres 7#ejh   

cubic inches7 of gas in solution1 which1
 added to  #bace litres1 gave a total of
 #ajdeg litres 7#fchb cubic inches7 at  
#bj  and #gfj1 which calculated to #j   
,c4 and #gfj mm4 atmospheric pressure   
7#cb  ,f4 and #cj inches7 gave a weight 
of #aigj grammes 7#cjbb grains7 of      
carbonic acid4    ,exactly half of the  
lime of the tartrate employed got used  
up in the  soluble salts formed during  
fermentation2 the other half was partly 
precipitated in the form of carbonate of
 lime1 partly dissolved in the  liquid  
by the carbonic acid4 ,the soluble salts
 seemed to us to be a  mixture or       
combination of #a equivalent of         
metacetate of lime1 with #b  equivalents
 of the acetate1 for every #aj          
equivalents of carbonic acid  produced1 
the whole corresponding to the          
fermentation of #c equivalents  of      
neutral tartrate of lime4#ach ,this     
point1 however1 is worthy of  being     
studied with greater care3 the present  
statement of the nature of  the products

 formed is given with all reserve4 ,for 
our point1 indeed1  the matter is of    
little importance1 since the equation of
 the  fermentation does not concern us4 
,illustration3 ,fig4 #fh4    ,after the 
completion of fermentation there was not
 a trace of tartrate  of lime remaining 
at the bottom of the vessel3 it had     
disappeared  gradually as it got broken 
up into the different products of       
fermentation1 and its place was taken by
 some crystallized carbonate of         
lime--the excess1 namely1 which had been
 unable to dissolve by the action  of   
the carbonic acid4 ,associated1         
moreover1 with this carbonate of lime   
there was a quantity of some kind of    
animal matter1 which1 under the         
microscope1 appeared to be composed of  
masses of granules mixed with  very fine
 filaments of varying lengths1 studded  
with minute dots1 and  presenting all   
the characteristics of a nitrogenous    
organic  substance4#aci ,that this was  
really the ferment is evident enough    

from  all that we have already said4 ,to
 convince ourselves more thoroughly of  
the fact1 and at the same time to enable
 us to observe the mode of  activity of 
the organism1 we instituted the         
following supplementary  observation4   
,side by side with the experiment just  
described1 we  conducted a similar one1 
which we intermitted after the          
fermentation was  somewhat advanced1 and
 about half of the tartrate dissolved4  
,breaking  off1 with a file1 the exit   
tube at the point where the neck began  
to  narrow off1 we took some of the     
deposit from the bottom by means of a   
long1 straight piece of tubing1 in order
 to bring it under microscopical        
examination4 ,we found it to consist of 
a host of long filaments of  extreme    
tenuity1 their diameter being about     
#a_/ajjjth of a millimetre  7#jjjjjci   
in472 their length varied1 in some cases
 being as much as  #a_/bjth of a        
millimetre 7#jjjai in474 ,a crowd of    
these long vibrios were  to be seen     

creeping slowly along1 with a sinuous   
movement1 showing  three1 four1 or even 
five flexures4 ,the filaments that were 
at rest had  the same aspect as these   
last1 with the exception that they      
appeared  punctate1 as though composed  
of a series of granules arranged in     
irregular order4 ,no doubt these were   
vibrios in which vital action had       
ceased1 exhausted specimens which we may
 compare with the old granular  ferment 
of beer1 whilst those in motion may be  
compared with young and  vigorous yeast4
 ,the absence of movement in the former 
seems to prove  that this view is       
correct4 ,both kinds showed a tendency  
to form  clusters1 the compactness of   
which impeded the movements of those    
which  were in motion4 ,moreover1 it was
 noticeable that the masses of these    
latter rested on tartrate not yet       
dissolved1 whilst the granular  clusters
 of the others rested directly on the   
glass1 at the bottom of  the flask1 as  
if1 having decomposed the tartrate1 the 

only carbonaceous  food at their        
disposal1 they had then died at the spot
 where we captured  them from inability 
to escape1 precisely in consequence of  
that state of  entanglement which they  
combined to form1 during the period of  
their  active development4 ,besides     
these we observed vibrios of the same   
diameter1 but of much smaller length1   
whirling round with great  rapidity1 and
 darting backwards and forwards2 these  
were probably  identical with the longer
 ones1 and possessed greater freedom of 
movement1 no doubt in consequence of    
their greater shortness4 ,not one of    
these vibrios could be found throughout 
the mass of the liquid4    ,we may      
remark that as there was a somewhat     
putrid odour from the deposit  in which 
the vibrios swarmed1 the action must    
have been one of  reduction1 and no     
doubt to this fact was due the greyish  
coloration of  the deposit4 ,we suppose 
that the substances employed1 however   
pure1  always contain some trace of     

iron1 which becomes converted into the  
sulphide1 the black colour of which     
would modify the originally white       
deposit of insoluble tartrate and       
phosphate4    ,but what is the nature of
 these vibrios8 ,we have already said   
that we  believe that they are nothing  
but the ordinary vibrios of             
putrefaction1  reduced to a state of    
extreme tenuity by the special          
conditions of  nutrition involved in the
 fermentable medium used2 in a word1 we 
think  that the fermentation in question
 might be called putrefaction of        
tartrate of lime4 ,it would be easy     
enough to determine this point by       
growing the vibrios of such a           
fermentation in media adapted to the    
production of the ordinary forms of     
vibrio2 but this is an experiment  which
 we have not ourselves tried4    ,one   
word more on the subject of these       
curious beings4 ,in a great many of     
them there appears to be something like 
a clear spot1 a kind of bead1 at  one of

 their extremities4 ,this is an illusion
 arising from the fact that  the        
extremity of these vibrios is curved1   
hanging downwards1 thus  causing a      
greater refraction at that particular   
point1 and leading us to  think that the
 diameter is greater at that extremity4 
,we may easily  undeceive ourselves if  
we watch the movements of the vibrio1   
when we  will readily recognize the     
bend1 especially as it is brought into  
the  vertical plane passing over the    
rest of the filament4 ,in this way we   
will see the bright spot1 the head      
disappear1 and then reappear4    ,the   
chief inference that it concerns us to  
draw from the preceding facts  is one   
which cannot admit of doubt1 and which  
we need not insist on any               
further--namely1 that vibrios1 as met   
with in the fermentation of neutral     
tartrate of lime1 are able to live and  
multiply when entirely deprived  of air4
         ,v4--,another ,example of ,life
 ,without ,air--,fermentation of        

,lactate of                             
,lime4      ,as another example of life 
without air1 accompanied by fermentation
  properly so called1 we may lastly cite
 the fermentation of lactate of  lime in
 a mineral medium4    ,in the experiment
 described in the last paragraph1 it    
will be remembered  that the            
ferment-liquid and the germs employed in
 its impregnation came  in contact with 
air1 although only for a very brief     
time4 ,now1  notwithstanding that we    
possess exact observations which prove  
that the  diffusion of oxygen and       
nitrogen in a liquid absolutely deprived
 of air1  so far from taking place      
rapidly1 is1 on the contrary1 a very    
slow  process indeed2 yet we were       
anxious to guard the experiment that we 
are  about to describe from the         
slightest possible trace of oxygen at   
the  moment of impregnation4    ,we     
employed a liquid prepared as follows3  
,into from #i to #aj litres  7somewhat  
over #b gallons7 of pure water the      

following salts#adj were  introduced    
successively1 viz3--                    
,pure lactate of lime           #bbe    
grammes                ,phosphate of    
ammonia           #jge grammes          
,phosphate of potassium         #jd     
grammes                ,sulphate of     
magnesium          #jd grammes          
,sulphate of ammonia            #jb     
grammes                #a gramme#aedc   
grains4    ,illustration3 ,fig4 #fi4    
,on ,march #bcrd1 #ahge1 we filled a #f 
litre 7about #aa pints7 flask1 of the   
shape represented in ,fig4 #fi1 and     
placed it over a heater4 ,another flame 
was placed below a vessel containing the
 same liquid1 into which the  curved    
tube of the flask was plunged4 ,the     
liquids in the flask and in  the basin  
were raised to boiling together1 and    
kept in this condition  for more than   
half-an-hour1 so as to expel all the air
 held in solution4  ,the liquid was     
several times forced out of the flask by
 the steam1 and  sucked back again2 but 

the portion which re-entered the flask  
was always  boiling4 ,on the following  
day1 when the flask had cooled1 we      
transferred  the end of the delivery    
tube to a vessel full of mercury and    
placed the  whole apparatus in an oven  
at a temperature varying between #be ,c4
 and  #cj ,c4 7#gg ,f4 and #hf ,f472    
then1 after having refilled the small   
cylindrical tap-funnel with carbonic    
acid1 we passed into it with all        
necessary precautions #aj c4c4 7#jce fl4
 oz47 of a liquid similar to that       
described1 which had been already in    
active fermentation for several  days   
out of contact with air and now swarmed 
with vibrios4 ,we then  turned the tap  
of the funnel1 until only a small       
quantity of liquid was  left1 just      
enough to prevent the access of air4 ,in
 this way the  impregnation was         
accomplished without either the         
ferment-liquid or the  ferment-germs    
having been brought in contact1 even for
 the shortest  space1 with the external 

air4 ,the fermentation1 the occurrence  
of which  at an earlier or later period 
depends for the most part on the        
condition  of the impregnating germs1   
and the number introduced in the act1 in
 this  case began to manifest itself by 
the appearance of minute bubbles from   
,march #bith4 ,but not till ,april #ith 
did we observe bubbles of larger size   
rise to the surface4 ,from that date    
onward they continued to come in        
increasing number1 from certain points  
at the bottom of the flask1 where  a    
deposit of earthy phosphates existed2   
and at the same time the liquid1  which 
for the first few days remained         
perfectly clear1 began to grow  turbid  
in consequence of the development of    
vibrios4 ,it was on the same  day that  
we first observed a deposit on the sides
 of carbonate of lime  in crystals4     
,it is a matter of some interest to     
notice here that1 in the mode of        
procedure adopted1 everything combined  
to prevent the interference of  air4 ,a 

portion of the liquid expelled at the   
beginning of the  experiment1 partly    
because of the increased temperature in 
the oven and  partly also by the force  
of the gas1 as it began to be evolved   
from the  fermentative action1 reached  
the surface of the mercury1 where1 being
  the most suitable medium we know for  
the growth of bacteria1 it speedily     
swarmed with these organisms4#ada ,in   
this way any passage of air1 if  such a 
thing were possible1 between the mercury
 and the sides of the  delivery-tube was
 altogether prevented1 since the        
bacteria would consume  every trace of  
oxygen which might be dissolved in the  
liquid lying on  the surface of the     
mercury4 ,hence it is impossible to     
imagine that the  slightest trace of    
oxygen could have got into the liquid in
 the flask4    ,before passing on we may
 remark that in this ready absorption of
 oxygen  by bacteria we have a means of 
depriving fermentable liquids of every  
trace of that gas with a facility and   

success equal or even greater than  by  
the method of preliminary boiling4 ,such
 a solution as we have  described1 if   
kept at summer heat1 without any        
previous boiling1 becomes  turbid in the
 course of twenty-four hours from a     
spontaneous  development of bacteria2   
and it is easy to prove that they absorb
 all  the oxygen held in solution4#adb  
,if we completely fill a flask of a few 
litres capacity 7about a gallon7 7,fig4 
#fg7 with the liquid described1  taking 
care to have the delivery-tube also     
filled1 and its opening  plunged under  
mercury1 and1 forty-eight hours         
afterwards1 by means of a  chloride of  
calcium bath1 expel from the liquid on  
the surface of the  mercury all the gas 
which it holds in solution1 this gas1   
when analyzed1  will be found to be     
composed of a mixture of nitrogen and   
carbonic acid  gas1 without the least   
trace of oxygen4 ,here1 then1 we have an
  excellent means of depriving the      
fermentable liquid of air2 we have      

simply to completely fill a flask with  
the liquid1 and place it in the  oven1  
merely avoiding any addition of butyric 
vibrios before the lapse  of two or     
three days4 ,we may wait even longer2   
and then1 if the liquid  does not become
 impregnated spontaneously with vibrio  
germs1 the liquid1  which at first was  
turbid from the presence of bacteria1   
will become  bright again1 since the    
bacteria when deprived of life1 or1 at  
least1 of  the power of moving1 after   
they have exhausted all the oxygen in   
solution1 will fall inert to the bottom 
of the vessel4 ,on several  occasions1  
we have determined this interesting     
fact1 which tends to  prove that the    
butyric vibrios cannot be regarded as   
another form of  bacteria1 inasmuch as1 
on the hypothesis of an original        
relation between  the two productions1  
butyric fermentation ought in every case
 to follow  the growth of bacteria4     
,we may also call attention to another  
striking experiment1 well suited  to    

show the effect of differences in the   
composition of the medium upon  the     
propagation of microscopic beings4 ,the 
fermentation which we last  described   
commenced on ,march #bgth and continued 
until ,may #ajth2 that to  which we are 
now to refer1 however1 was completed in 
four days1 the  liquid employed being   
similar in composition and quantity to  
that  employed in the former experiment4
 ,on ,april #bcrd1 #ahge1 we filled a   
flask of the same shape as that         
represented in ,fig4 #fi1 and of similar
  capacity1 viz41 #f litres1 with a     
liquid composed as described at page    
#bic4 ,this liquid had been previously  
left to itself for five days in  large  
open flasks1 in consequence of which it 
had developed an abundant  growth of    
bacteria4 ,on the fifth day a few       
bubbles1 rising from the  bottom of the 
vessels1 at long intervals1 betokened   
the commencement of  butyric            
fermentation1 a fact1 moreover1         
confirmed by the microscope1 in  the    

appearance of the vibrios of this       
fermentation in specimens of the  liquid
 taken from the bottom of the vessels1  
the middle of its mass1 and  even in the
 layer on the surface that was swarming 
with bacteria4 ,we  transferred the     
liquid so prepared to the #f-litre flask
 arranged over  the mercury4 ,by evening
 a tolerably active fermentation had    
begun to  manifest itself4 ,on the #bdth
 this fermentation was proceeding with  
astonishing rapidity1 which continued   
during the #beth and #bfth4 ,during  the
 evening of the #bfth it slackened1 and 
on the #bgth all signs of  fermentation 
had ceased4 ,this was not1 as might be  
supposed1 a sudden  stoppage1 due to    
some unknown cause2 the fermentation was
 actually  completed1 for when we       
examined the fermented liquid on the    
#bhth we  could not find the smallest   
quantity of lactate of lime4 ,if the    
needs of  industry should ever require  
the production of large quantities of   
butyric acid1 there would1 beyond doubt1

 be found in the preceding fact         
valuable information in devising an easy
 method of preparing that  product in   
abundance4#adc    ,before we go any     
further1 let us devote some attention to
 the vibrios of  the preceding          
fermentations4    ,on ,may #bgth1 #ahfb1
 we completely filled a flask1 capable  
of holding  #bghj litres 7about five    
pints71 with the solution of lactate and
  phosphates4#add ,we refrained from    
impregnating it with any germs4 ,the    
liquid became turbid from a development 
of bacteria1 and then underwent  butyric
 fermentation4 ,by ,june #ith the       
fermentation had become  sufficiently   
active to enable us to collect in the   
course of twenty-four  hours1 over      
mercury1 as in all our experiments1     
about #ajj cc4 7about #f  cubic inches7 
of gas4 ,by ,june #aath1 judging from   
the volume of gas  liberated in the     
course of twenty-four hours1 the        
activity of the  fermentation had       
doubled4 ,we examined a drop of the     

turbid liquid4 ,here  are the notes     
accompanying the sketch 7,fig4 #gj7 as  
they stand in our  note-book3--8,a swarm
 of vibrios1 so active in their         
movements that the  eye has great       
difficulty in following them4 ,they may 
be seen in pairs  throughout the field1 
apparently making efforts to separate   
from each  other4 ,the connection would 
seem to be by some invisible1 gelatinous
  thread1 which yields so far to their  
efforts that they succeed in  breaking  
away from actual contact1 but yet are1  
for a while1 so far  restrained that the
 movements of one have a visible effect 
on those of  the other4 ,by and by1     
however1 we see a complete separation   
effected1  and each moves on its        
separate way with an activity still     
greater than  it had before40           
,illustration3 ,fig4 #gj4    ,one of the
 best methods that can be employed for  
the microscopical  examination of these 
vibrios1 quite out of contact with air1 
is the  following3--,after butyric      

fermentation has been going on for      
several days  in a flask1 ,a 7,fig4     
#ga71 we connect this flask by an       
india-rubber tube  with one of the      
flattened bulbs previously described1   
page #aef 7,fig4  #ca71 which we then   
place on the stage of the microscope    
7,fig4 #ga74 ,when  we wish to make an  
observation we close1 under the mercury1
 at the point  b1 the end of the        
drawn-out and bent delivery-tube4 ,the  
continued  evolution of gas soon exerts 
such a pressure within the flask1 that  
when  we open the tap r1 the liquid is  
driven into the bulb l l1 until it      
becomes quite full and the liquid flows 
over into the glass ,v4 ,in this  manner
 we may bring the vibrios under         
observation without their coming  into  
contact with the least trace of air1 and
 with as much success as if  the bulb1  
which takes the place of an object      
glass1 had been plunged  into the very  
centre of the flask4 ,the movements and 
fissiparous  multiplication of the      

vibrios may thus be seen in all their   
beauty1 and  it is indeed a most        
interesting sight4 ,the movements do not
 immediately  cease when the temperature
 is suddenly lowered1 even to a         
considerable  extent1 #ae ,c4 7#ei ,f47 
for example2 they are only slackened4   
,nevertheless1 it is better to observe  
them at the temperatures most           
favourable to fermentation1 even in the 
oven where the vessels employed  in the 
experiment are kept at a temperature    
between #be ,c4 and #cj ,c4  7#gg ,f4   
and #hf ,f474    ,illustration3 ,fig4   
#ga4    ,we may now continue our account
 of the fermentation which we were      
studying when we made this last         
digression4 ,on ,june #agth that        
fermentation produced three times as    
much gas as it did on ,june #aath1  when
 the residue of hydrogen1 after         
absorption by potash1 was #gbf per      
cent42 whilst on the #agth it was only  
#dib per cent4 ,let us again  discuss   
the microscopic aspect of the turbid    

liquid at this stage4  ,appended is the 
sketch we made 7,fig4 #gb7 and our notes
 on it3--8,a most  beautiful object3    
vibrios all in motion1 advancing or     
undulating4 ,they  have grown           
considerably in bulk and length since   
the #aath2 many of them  are joined     
together into long sinuous chains1 very 
mobile at the  articulations1 visibly   
less active and more wavering in        
proportion to  the number that go to    
form the chain1 or the length of the    
individuals40  ,this description is     
applicable to the majority of the       
vibrios which  occur in cylindrical rods
 and are homogeneous in aspect4 ,there  
are  others1 of rare occurrence in      
chains1 which have a clear corpuscle1   
that  is to say1 a portion more         
refractive than the other parts of the  
segments1 at one of their extremities4  
,sometimes the foremost segment  has the
 corpuscle at one end1 sometimes at the 
other4 ,the long segments  of the       
commoner kind attain a length of from   

#aj to #cj and even #de  thousandths of 
a millimetre4 ,their diameter is from   
#a- to #b1 very  rarely #c1 thousandths 
of a millimetre4#ade    ,illustration3  
,fig4 #gb4    ,illustration3 ,fig4 #gc4 
,on ,june #bhth1 fermentation was quite 
finished2 there was no longer any  trace
 of gas1 nor any lactate in solution4   
,all the infusoria were lying           
motionless at the bottom of the flask4  
,the liquid clarified by degrees1  and  
in the course of a few days became quite
 bright4 ,here we may  inquire1 were    
these motionless infusoria1 which from  
complete exhaustion  of the lactate1 the
 source of the carbonaceous part of     
their food1 were  now lying inert at the
 bottom of the fermenting vessel--were  
they dead  beyond power of revival8#adf 
,the following experiment leads us to   
believe that they were not perfectly    
lifeless1 and that they behave in  the  
same manner as the yeast of beer1 which1
 after it has decomposed all  the sugar 
in a fermentable liquid1 is ready to    

revive and multiply in a  fresh         
saccharine medium4 ,on ,april #bbnd1    
#ahge1 we left in the oven1 at a        
temperature of #be ,c4 7#gg ,f471 a     
fermentation of lactate of lime that    
had been completed4 ,the delivery tube  
of the flask1 ,a1 7,fig4 #gc7 in  which 
it had taken place had never been       
withdrawn from under the  mercury4 ,we  
kept the liquid under observation daily1
 and saw it  gradually become brighter2 
this went on for fifteen days4 ,we then 
filled  a similar flask1 ,b1 with the   
solution of lactate1 which we boiled1   
not  only to kill the germs of vibrios  
which the liquid might contain1 but     
also to expel the air that it held in   
solution4 ,when the flask1 ,b1 had      
cooled1 we connected the two flasks1    
avoiding the introduction of  air#adg1  
after having slightly shaken the flask1 
,a1 to stir up the  deposit at the      
bottom4 ,there was then a pressure1 due 
to carbonic acid  at the end of the     
delivery tube of this latter flask1 at  

the point a1  so that on opening the    
taps r and s1 the deposit at the bottom 
of  flask ,a was driven over into flask 
,b1 which in consequence was            
impregnated with the deposit of a       
fermentation that had been completed    
fifteen days before4 ,two days after    
impregnation1 the flask ,b began to     
show signs of fermentation4 ,it follows1
 that the deposit of vibrios of a       
completed butyric fermentation may be   
kept1 at least for a certain time1      
without losing the power of causing     
fermentation4 ,it furnishes a butyric   
ferment1 capable of revival and action  
in a suitable1 fresh1 fermentable       
medium4    ,the reader who has          
attentively studied the facts which we  
have placed  before him cannot1 in our  
opinion1 entertain the least doubt on   
the  subject of the possible            
multiplication of the vibrios of a      
fermentation  of lactate of lime out of 
contact with atmospheric oxygen4 ,if    
fresh  proofs of this important         

proposition were necessary1 they might  
be found  in the following observations1
 from which it may be inferred that     
atmospheric oxygen is capable of        
suddenly checking a fermentation        
produced by butyric vibrios1 and        
rendering them absolutely motionless1   
so that it cannot be necessary to enable
 them to live4 ,on ,may #gth1 #ahfb1  we
 placed in the oven a flask holding     
#behj litres 7#d- pints71 and  filled   
with the solution of lactate of lime and
 phosphates1 which we had  impregnated  
on the #ith with two drops of a liquid  
in butyric  fermentation4 ,in the course
 of a few days fermentation declared    
itself3  on the #afth it was in         
progress1 but feebly2 on the #ahth it   
was active2  on the #cjth it was very   
active4 ,on ,june #ast it yielded hourly
 #ce c4c4  7#bc cubic inches7 of gas1   
containing ten per cent4 of hydrogen4   
,on the  #bnd we began the study of the 
action of air on the vibrios of this    
fermentation4 ,to do this we cut off the

 delivery-tube on a level with  its     
point of junction to the flask1 then    
with a #ej c4c4 pipette we took  out    
that quantity 7#a-c_/d fl4 oz47 of      
liquid which was1 of course1  replaced  
at once by air4 ,we then reversed the   
flask with the opening  under the       
mercury1 and shook it every ten minutes 
for more than an hour4  ,wishing to make
 sure1 to begin with1 that the oxygen   
had been absorbed1  we connected under  
the mercury the beak of the flask by    
means of a thin  india-rubber tube      
filled with water1 with a small flask1  
the neck of  which had been drawn out1  
and was filled with water2 we then      
raised the  large flask with the smaller
 kept above it4 ,a ,mohr's clip1 which  
closed  the india-rubber tube1 and which
 we then opened1 permitted the water    
contained in the small flask to pass    
into the large one1 whilst the gas1  on 
the contrary1 passed upwards from the   
large flask into the small one4  ,we    
analyzed the gas immediately1 and found 

that1 allowing for carbonic  acid and   
hydrogen1 it did not contain more than  
#adb per cent4 of  oxygen1 which        
corresponds to an absorption of #ff     
c4c41 or of #cc c4c4  7#jb cubic inch7  
of oxygen for the #ej c4c4 7#cje cubic  
inches7 of air  employed4 ,lastly1 we   
again established connection by an      
india-rubber  tube between the flasks1  
after having seen by microscopical      
examination  that the movements of the  
vibrios were very languid4 ,fermentation
 had  become less vigorous without      
having actually ceased1 no doubt because
  some portions of the liquid had not   
been brought into contact with the      
atmospheric oxygen1 in spite of the     
prolonged shaking that the flask had    
undergone after the introduction of the 
air4 ,whatever the cause might  have    
been1 the significance of the phenomenon
 is not doubtful4 ,to assure  ourselves 
further of the effect of air on the     
vibrios1 we half filled  two test tubes 
with the fermenting liquid taken from   

another  fermentation which had also    
attained its maximum of intensity1 into 
one  of which we passed a current of    
air1 into the other carbonic acid gas4  
,in the course of half an hour1 all the 
vibrios in the aerated tube were  dead1 
or at least motionless1 and fermentation
 had ceased4 ,in the other  tube1 after 
three hours' exposure to the effects of 
the carbonic acid  gas1 the vibrios were
 still very active1 and fermentation was
 going on4    ,there is a most simple   
method of observing the deadly effect of
  atmospheric air upon vibrios4 ,we have
 seen in the microscopical  examination 
made by means of the apparatus          
represented in ,fig4 #ga1 how           
remarkable were the movements of the    
vibrios when absolutely deprived of     
air1 and how easy it was to discern     
them4 ,we will repeat this  observation1
 and at the same time make a comparative
 study of the same  liquid1 under the   
microscope1 in the ordinary way1 that is
 to say1 by  placing a drop of the      

liquid on an object-glass1 and covering 
it with a  thin glass slip1 a method    
which must necessarily bring the drop   
into  contact with air1 if only for a   
moment4 ,it is surprising what a        
remarkable difference is observed       
immediately between the movements of    
the vibrios in the bulb and of those    
under the glass4 ,in the case of the    
latter we generally see all movement at 
once cease near the edges of the  glass1
 where the drop of liquid is in direct  
contact with the air2 the  movements    
continue for a longer or shorter time   
about the centre1 in  proportion as the 
air is more or less intercepted by the  
vibrios at the  circumference of the    
liquid4 ,it does not require much skill 
in  experiments of this kind to enable  
one to see plainly that immediately     
after the glass has been placed on the  
drop1 which has been affected all  over 
by atmospheric air1 the whole of the    
vibrios seem to languish and  to        
manifest symptoms of illness--we can    

think of no better expression to        
explain what we see taking place--and   
that they gradually recover their       
activity about the centre1 in proportion
 as they find themselves in a  part of  
the medium that is less affected by the 
presence of oxygen4    ,some most       
curious facts are to be found in        
connection with an  observation1 the    
correlative and inverse of the          
foregoing1 on the  ordinary arobian     
bacteria4 ,if we examine below the      
microscope a drop of  liquid full of    
these organisms under a coverslip1 we   
very soon observe a  cessation of motion
 in all the bacteria which lie in the   
central portion  of the liquid1 where   
the oxygen rapidly disappears to supply 
the  necessities of the bacteria        
existing there2 whilst1 on the other    
hand1  near the edges of the cover-glass
 the movements are very active1 in      
consequence of the constant supply of   
air4 ,in spite of the speedy death  of  
the bacteria beneath the centre of the  

glass1 we see life prolonged  there if  
by chance a bubble of air has been      
enclosed4 ,all round this  bubble a vast
 number of bacteria collect in a thick1 
moving circle1 but  as soon as all the  
oxygen of the bubble has been absorbed  
they fall  apparently lifeless1 and are 
scattered by the movement of the        
liquid4#adh    ,we may here be permitted
 to add1 as a purely historical matter1 
that it  was these two observations just
 described1 made successively one day in
  #ahfa1 on vibrios and bacteria1 that  
first suggested to us the idea of  the  
possibility of life without air1 and    
caused us to think that the  vibrios    
which we met so frequently in our lactic
 fermentations must be  the true butyric
 ferment4    ,we may pause a moment to  
consider an interesting question in     
reference  to the two characters under  
which vibrios appear in butyric         
fermentations4 ,what is the reason that 
some vibrios exhibit refractive         
corpuscles1 generally of a lenticular   

form1 such as we see in ,fig4 #gb8  ,we 
are strongly inclined to believe that   
these corpuscles have to do  with a     
special mode of reproduction in the     
vibrios1 common alike to the  anarobian 
forms which we are studying1 and the    
ordinary arobian forms  in which also   
the corpuscles of which we are speaking 
may occur4 ,the  explanation of the     
phenomenon1 from our point of view1     
would be that1  after a certain number  
of fissiparous generations1 and under   
the  influence of variations in the     
composition of the medium1 which is     
constantly changing through fermentation
 as well as through the active  life of 
the vibrios themselves1 cysts1 which are
 simply the refractive  corpuscles1 form
 along them at different points4 ,from  
these gemmules we  have ultimately      
produced vibrios1 ready to reproduce    
others by the  process of transverse    
division for a certain time1 to be      
themselves  encysted later on4 ,various 
observations incline us to believe that1

 in  their ordinary form of minute1     
soft1 exuberant rods1 the vibrios perish
  when submitted to desiccation1 but    
when they occur in the corpuscular or   
encysted form they possess unusual      
powers of resistance1 and may be        
brought to the state of dry dust and be 
wafted about by winds4 ,none of  the    
matter which surrounds the corpuscle or 
cyst seems to take part in  the         
preservation of the germ1 when the cyst 
is formed1 for it is all  re-absorbed1  
gradually leaving the cyst bare4 ,the   
cysts appear as masses  of corpuscles1  
in which the most practised eye cannot  
detect anything of  an organic nature1  
or anything to remind one of the vibrios
 which  produced them2 nevertheless1    
these minute bodies are endowed with a  
latent vital action1 and only await     
favourable conditions to develop  long  
rods of vibrios4 ,we are not1 it is     
true1 in a position to adduce  any very 
forcible proofs in support of these     
opinions4 ,they have been  suggested to 

us by experiments1 none of which1       
however1 have been  absolutely decisive 
in their favour4 ,we may cite one of our
 observations  on this subject4    ,in a
 fermentation of glycerine in a mineral 
medium--the glycerine was  fermenting   
under the influence of butyric          
vibrios--after we had  determined the1  
we may say1 exclusive presence of       
lenticular vibrios1  with refractive    
corpuscles1 we observed the             
fermentation1 which1 for  some unknown  
reason1 had been very languid1 suddenly 
become extremely  active1 but now       
through the influence of ordinary       
vibrios4 ,the gemmules  with brilliant  
corpuscles had almost disappeared2 we   
could see but very  few1 and those now  
consisted of the refractive bodies      
alone1 the bulk of  the vibrios         
accompanying them having undergone some 
process of  re-absorption4    ,another  
observation which still more closely    
accords with this  hypothesis is given  
in our work on the silkworm disease     

7vol4 i41 page  #bef74 ,we there        
demonstrate that1 when we place in water
 some of the dust  formed of desiccated 
vibrios1 containing a host of these     
refractive  corpuscles1 in the course of
 a very few hours large vibrios appear1 
well-developed rods fully grown1 in     
which the brilliant points are  absent2 
whilst in the water no process of       
development from smaller  vibrios is to 
be discerned1 a fact which seems to show
 that the former  had issued fully grown
 from the refractive corpuscles1 just as
 we see  colpoda issue with their adult 
aspect from the dust of their cysts4    
,this observation1 we may remark1       
furnishes one of the best proofs that   
can be adduced against the spontaneous  
generation of vibrios or  bacteria1     
since it is probable that the same      
observation applies to  bacteria4 ,it is
 true that we cannot say of mere points 
of dust1 examined  under the microscope1
 that one particular germ belongs to    
vibrio1  another to bacterium2 but how  

is it possible to doubt that the vibrios
  issue1 as we see them1 from an ovum of
 some kind1 a cyst1 or germ1 of         
determinate character1 when1 after      
having placed some of these             
indeterminate motes of dust into clean  
water1 we suddenly see1 after an        
interval of not more than one or two    
hours1 an adult vibrio crossing the     
field of the microscope1 without our    
having been able to detect any          
intermediate state between its birth and
 adolescence8    ,it is a question      
whether differences in the aspect and   
nature of  vibrios1 which depend upon   
their more or less advanced age1 or are 
occasioned by the influence of certain  
conditions of the medium in which  they 
propagate1 do not bring about           
corresponding changes in the course  of 
the fermentation and the nature of its  
products4 ,judging at least  from the   
variations in the proportions of        
hydrogen and carbonic acid gas  produced
 in butyric fermentations1 we are       

inclined to think that this  must be the
 case2 nay1 more1 we find that hydrogen 
is not even a  constant product in these
 fermentations4 ,we have met with       
butyric  fermentations of lactate of    
lime which did not yield the minutest   
trace  of hydrogen1 or anything besides 
carbonic acid4 ,fig4 #gd represents the 
vibrios which we observed in a          
fermentation of this kind4 ,they present
  no special features4 ,butyl alcohol   
is1 according to our observations1 an   
ordinary product1 although it varies and
 is by no means a necessary  concomitant
 of these fermentations4 ,it might be   
supposed1 since butylic  alcohol may be 
produced1 and hydrogen be in deficit1   
that the proportion  of the former of   
these products would attain its maximum 
when the latter  assumed a minimum4     
,this1 however1 is by no means the case2
 even in those  few fermentations that  
we have met with in which hydrogen was  
absent1  there was no formation of      
butylic alcohol4    ,illustration3 ,fig4

 #gd4    ,from a consideration of all   
the facts detailed in this paragraph we 
can  have no hesitation in concluding   
that1 on the one hand1 in cases of      
butyric fermentation1 the vibrios which 
abound in them and constitute  their    
ferment1 live without air or free       
oxygen2 and that1 on the other  hand1   
the presence of gaseous oxygen operates 
prejudicially against the  movements and
 activity of those vibrios4 ,but now    
does it follow that the  presence of    
minute quantities of air brought into   
contact with a liquid  undergoing       
butyric fermentation would prevent the  
continuance of that  fermentation1 or   
even exercise any check upon it8 ,we    
have not made any  direct experiments   
upon this subject2 but we should not be 
surprised to  find that1 so far from    
hindering1 air may1 under such          
circumstances1  facilitate the          
propagation of the vibrios and          
accelerate fermentation4  ,this is      
exactly what happens in the case of     

yeast4 ,but how could we  reconcile     
this1 supposing it were proved to be the
 case1 with the fact  just insisted on  
as to the danger of bringing the butyric
 vibrios into  contact with air8 ,it may
 be possible that life without air      
results  from habit1 whilst death       
through air may be brought about by a   
sudden  change in the conditions of the 
existence of the vibrios4 ,the following
  remarkable experiment is well known3  
,a bird is placed in a glass jar of  one
 or two litres 7#fj to #abj cubic       
inches7 in capacity1 which is then      
closed4 ,after a time the creature      
exhibits every sign of intense          
uneasiness and asphyxia long before it  
dies2 a similar bird of the same  size  
is introduced into the jar2 the death of
 the latter takes place                 
instantaneously1 whilst the life of the 
former may still be prolonged  under    
these conditions for a considerable     
time1 and there is no  difficulty even  
in restoring the bird to perfect health 

by taking it out  of the jar4 ,it seems 
impossible to deny that we have here a  
case of the  adaptation of an organism  
to the gradual contamination of the     
medium2  and so it may likewise happen  
that the anarobian vibrios of a butyric 
fermentation1 which develop and multiply
 absolutely without free oxygen1  perish
 immediately when suddenly taken out of 
their airless medium1 and  that the     
result might be different if they had   
been gradually brought  under the action
 of air in small quantities at a time4  
,we are compelled here to admit that    
vibrios frequently abound in liquids    
exposed to the air1 and that they       
appropriate the atmospheric oxygen1  and
 could not withstand a sudden removal   
from its influence4 ,must we1  then1    
believe that such vibrios are absolutely
 different from those of  butyric       
fermentations8 ,it would1 perhaps1 be   
more natural to admit that  in the one  
case there is an adaptation to life with
 air1 and in the  other case an         

adaptation to life without air2 each of 
these varieties  perishing when suddenly
 transferred from its habitual condition
 to that  of the other1 whilst by a     
series of progressive changes one might 
be  modified into the other4#adi ,we    
know that in the case of alcoholic      
ferments1 although these can actually   
live without air1 propagation is        
wonderfully assisted by the presence of 
minute quantities of air2 and  certain  
experiments1 which we have not yet      
published1 lead us to believe  that1    
after having lived without air1 they    
cannot be suddenly exposed  with        
impunity to the influence of large      
quantities of oxygen4    ,we must not   
forget1 however1 that arobian torul and 
anarobian  ferments present an example  
of organisms apparently identical1 in   
which1  however1 we have not yet been   
able to discover any ties of a common   
origin4 ,hence we were forced to regard 
them as distinct species2 and so  it is 
possible that there may likewise be     

arobian and anarobian  vibrios without  
any transformation of the one into the  
other4    ,the question has been raised 
whether vibrios1 especially those which 
we  have shown to be the ferment of     
butyric and many other fermentations1   
are1 in their nature1 animal or         
vegetable4 ,m4 ,ch4 ,robin attaches     
great  importance to the solution of    
this question1 of which he speaks as    
follows#aej3--8,the determination of the
 nature1 whether animal or  vegetable1  
of organisms1 either as a whole or in   
respect to their  anatomical parts1     
assimilative or reproductive1 is a      
problem which has  been capable of      
solution for a quarter of a century4    
,the method has been  brought to a state
 of remarkable precision1               
experimentally1 as well as  in its      
theoretical aspects1 since those who    
devote their attention to  the organic  
sciences consider it indispensable in   
every observation and  experiment to    
determine accurately1 before anything   

else1 whether the  object of their study
 is animal or vegetable in its nature1  
whether  adult or otherwise4 ,to neglect
 this is as serious an omission for such
  students1 as for chemists would be the
 neglecting to determine whether  it is 
nitrogen or hydrogen1 urea or stearine  
that has been extracted  from a tissue1 
or which it is whose combinations they  
are studying in  this or that chemical  
operation4 ,now1 scarcely any one of    
those who  study fermentations1 properly
 so called1 and putrefactions1 ever pay 
attention to the preceding data4444     
,among the observers to whom ,i allude  
even ,m4 ,pasteur is to be found1 who1  
even in his most recent  communications1
 omits to state definitely what is the  
nature of many of  the ferments which he
 has studied1 with the exception1       
however1 of those  which belong to the  
cryptogamic group called torulace4      
,various  passages in his works seem to 
show that he considers the cryptogamic  
organisms called bacteria1 as well as   

those known as vibrios1 as  belonging to
 the animal kingdom 7see ,bulletin de   
l',acadmie de  ,mdecine1 ,paris1 #ahge1 
pp4 #bdi1 #bea1 especially #bef1 #bff1  
#bfg1 #bhi1 and  #bij74 ,these would be 
very different1 at least                
physiologically1 the  former being      
arobian1 whilst the vibrios are         
anarobian1 that is to  say1 requiring no
 air to enable them to live1 and being  
killed by  oxygen1 should it be         
dissolved in the liquid to any          
considerable  extent40    ,we are unable
 to see the matter in the same light as 
our learned  colleague does2 to our     
thinking1 we should be labouring under a
 great  delusion were we to suppose     
8that it is quite as serious an omission
 not  to determine the animal or        
vegetable nature of a ferment as it     
would be  to confound nitrogen with     
hydrogen1 or urea with stearine40 ,the  
importance of the solutions of disputed 
questions often depends upon the  point 
of view from which these are regarded4  

,as far as the result of our  labours is
 concerned1 we devoted our attention to 
these two questions  exclusively3--#a4  
,is the ferment1 in every fermentation  
properly so  called1 an organized being8
 #b4 ,can this organized being live     
without  air8 ,now1 what bearing can the
 question of the animal or vegetable    
nature of the ferment1 of the organized 
being1 have upon the  investigation of  
these two problems8 ,in studying butyric
 fermentation1  for example1 we         
endeavoured to establish these two      
fundamental  points3--#a4 ,the butyric  
ferment is a vibrio4 #b4 ,this vibrio   
may  dispense with air in its life1 and1
 as a matter of fact1 does dispense     
with it in the act of producing butyric 
fermentation4 ,we did not  consider it  
at all necessary to pronounce any       
opinion as to the animal  or vegetable  
nature of this organism1 and1 even up to
 the present  moment1 the idea that     
vibrio is an animal and not a plant is1 
in our  minds1 a matter of sentiment    

rather than of conviction4    ,m4       
,robin1 however1 would have no          
difficulty in determining the limits of 
the two kingdoms4 ,according to him1    
8every variety of cellulose is1 we  may 
say1 insoluble in ammonia1 as also are  
the reproductive elements of  plants1   
whether male or female4 ,whatever phase 
of evolution the elements  which        
reproduce a new individual may have     
reached1 treatment with this  reagent1  
either cold or raised to boiling1 leaves
 them absolutely intact  under the eyes 
of the observer1 except that their      
contents1 from being  partially         
dissolved1 become more transparent4     
,every vegetable1 whether  microscopic  
or not1 every mycelium1 and every spore 
thus preserves in  its entirety its     
special characteristics of form1 volume1
 and structural  arrangements2 whilst in
 the case of microscopic animals1 or the
 ova and  microscopic embryos of        
different members of the animal kingdom1
 the very  opposite is the case40    ,we

 should be glad to learn that the       
employment of a drop of ammonia  would  
enable us to pronounce an opinion1 with 
this degree of confidence1  on the      
nature of the lowest microscopic beings2
 but is ,m4 ,robin  absolutely correct  
in his assumptions8 ,that gentleman     
himself remarks  that spermatozoa1 which
 belong to animal organisms1 are        
insoluble in  ammonia1 the effect of    
which is merely to make them paler4 ,if 
a  difference of action in certain      
reagents1 in ammonia1 for example1 were 
sufficient to determine the limits of   
the animal and vegetable kingdoms1      
might we not argue that there must be a 
very great and natural  difference      
between moulds and bacteria1 inasmuch as
 the presence of a  small quantity of   
acid in the nutritive medium facilitates
 the growth  and propagation of the     
former1 whilst it is able to prevent the
 life of  bacteria and vibrios8         
,although1 as is well known1 movement is
 not an  exclusive characteristic of    

animals1 yet we have always been        
inclined to  regard vibrios as animals1 
on account of the peculiar character of 
their  movements4 ,how greatly they     
differ in this respect from the         
diatomac1  for example6 ,when the vibrio
 encounters an obstacle it turns1 or    
after  having assured itself by some    
visual effort or other that it cannot   
overcome it1 it retraces its steps4 ,the
 colpoda--undoubted  infusoria--behave  
in an exactly similar manner4 ,it is    
true one may argue  that the zoospores  
of certain cryptogamia exhibit similar  
movements2 but  do not these zoospores  
possess as much of an animal nature as  
do the  spermatozoa8 ,as far as bacteria
 are concerned1 when1 as already        
remarked1 we see them crowd round a     
bubble of air in a liquid to prolong    
their life1 oxygen having failed them   
everywhere else1 how can we avoid       
believing that they are animated by an  
instinct for life1 of the same  kind as 
that which we find in animals4 ,m4      

,robin seems to us to be wrong  in      
supposing that it is possible to draw   
any absolute line of separation  between
 the animal and vegetable kingdoms4 ,the
 settlement of this line1  however1 we  
repeat again1 no matter what it may be1 
has no serious  bearing upon the        
questions that have been the subject of 
our researches4    ,in like manner the  
difficulty which ,m4 ,robin has raised  
in objecting to  the employment of the  
word germ1 when we cannot specify       
whether the  nature of that germ is     
animal or vegetable1 is in many respects
 an  unnecessary one4 ,in all the       
questions which we have discussed1      
whether  we were speaking of            
fermentation or spontaneous generation1 
the word  germ has been used in the     
sense of origin of living organism4 ,if 
,liebig1 for example1 said of an        
albuminous substance that it gave birth 
to ferment1 could we contradict him more
 plainly than by replying3 8,no2        
ferment is an organized being1 the germ 

of which is always present1 and  the    
albuminous substance merely serves by   
its occurrence to nourish the  germ and 
its successive generations40    ,in our 
,memoir of #ahfb1 on so-called          
spontaneous generations1 would it  not  
have been an entire mistake to have     
attempted to assign specific  names to  
the microscopic organisms which we met  
with in the course of  our observations8
 ,not only would we have met with       
extreme difficulty in  the attempt1     
arising from the state of extreme       
confusion which even in  the present day
 exists in the classification and       
nomenclature of these  microscopic      
organisms1 but we should have been      
forced to sacrifice  clearness in our   
work besides2 at all events1 we should  
have wandered  from our principal       
object1 which was the determination of  
the presence  or absence of life in     
general1 and had nothing to do with the 
manifestation of a particular kind of   
life in this or that species1  animal or

 vegetable4 ,thus we have systematically
 employed the vaguest  nomenclature1    
such as mucors1 torul1 bacteria1 and    
vibrios4  ,there was nothing arbitrary  
in our doing this1 whereas there is much
  that is arbitrary in adopting a       
definite system of nomenclature1 and    
applying it to organisms but imperfectly
 known1 the differences or  resemblances
 between which are only recognizable    
through certain  characteristics1 the   
true signification of which is obscure4 
,take1 for  example1 the extensive array
 of widely different systems that have  
been  invented during the last few years
 for the species of the genera          
bacterium and vibrio in the works of    
,cohn1 ,h4 ,hoffmann1 ,hallier1 and     
,billroth4 ,the confusion which prevails
 here is very great1 although we  do not
 of course by any means place these     
different works on the same  footing as 
regards their respective merits4    ,m4 
,robin is1 however1 right in recognizing
 the impossibility of  maintaining in   

the present day1 as he formerly did1    
8that fermentation  is an exterior      
phenomenon1 going on outside cryptogamic
 cells1 a  phenomenon of contact4 ,it is
 probably10 he adds1 8an interior and   
molecular action at work in the inmost  
recesses of the substance of each       
cell40 ,from the day when we first      
proved that it is possible for all      
organized ferments1 properly so called1 
to spring up and multiply from  their   
respective germs1 sown1 whether         
consciously or by accident1 in a        
mineral medium free from organic and    
nitrogenous matters other than  ammonia1
 in which medium the fermentable matter 
alone is adapted to  provide the ferment
 with whatever carbon enters into its   
composition1  from that time forward the
 theories of ,liebig1 as well as that of
  ,berzelius1 which ,m4 ,robin formerly 
defended1 have had to give place to     
others more in harmony with facts4 ,we  
trust that the day will come when  ,m4  
,robin will likewise acknowledge that he

 has been in error on the  subject of   
the doctrine of spontaneous generation1 
which he continues to  affirm1 without  
adducing any direct proofs in support of
 it1 at the end  of the article to which
 we have been here replying4    ,we have
 devoted the greater part of this       
chapter to the establishing  with all   
possible exactness the extremely        
important physiological fact  of life   
without air1 and its correlation to the 
phenomena of  fermentations properly so 
called--that is to say1 of those which  
are due  to the presence of microscopic 
cellular organisms4 ,this is the chief  
basis of the new theory that we propose 
for the explanation of these  phenomena4
 ,the details into which we have entered
 were indispensable on  account of the  
novelty of the subject no less than on  
account of the  necessity we were under 
of combating the criticisms of the two  
,german  naturalists1 ,drs4 ,oscar      
,brefeld and ,traube1 whose works had   
cast some  doubts on the correctness of 

the facts upon which we had based the   
preceding propositions4 ,we have much   
pleasure in adding that at the very     
moment when we were revising the proofs 
of this chapter1 we received  from ,m4  
,brefeld an essay1 dated from ,berlin1  
,january1 #ahgf1 in which1  after       
describing his later experimental       
researches1 he owns with  praiseworthy  
frankness that ,dr4 ,traube and he were 
both of them  mistaken4 ,life without   
air is now a proposition which he       
accepts as  perfectly demonstrated4 ,he 
has witnessed it in the case of mucor   
racemosus1 and has also verified it in  
the case of yeast4 8,if10 he  says1     
8after the results of my previous       
researches1 which ,i conducted  with all
 possible exactness1 ,i was inclined to 
consider ,pasteur's  assertions as      
inaccurate1 and to attack them1 ,i have 
no hesitation now  in recognizing them  
as true1 and in proclaiming the service 
which  ,pasteur has rendered to science 
in being the first to indicate the exact

  relation of things in the phenomenon  
of fermentation40 ,in his later         
researches4 ,dr4 ,brefeld has adopted   
the method which we have long  employed 
for demonstrating the life and          
multiplication of butyric  vibrios in   
the entire absence of air1 as well as   
the method of  conducting growths in    
mineral media associated with the       
fermentable  substance4 ,we need not    
pause to consider certain other         
secondary  criticisms of ,dr4 ,brefeld4 
,a perusal of the present work will1 we 
trust1  convince him that they are based
 on no surer foundation than were his   
former criticisms4    ,to bring one's   
self to believe in a truth that has just
 dawned upon one  is the first step     
towards progress2 to persuade others is 
the second4  ,there is a third step1    
less useful perhaps1 but highly         
gratifying  nevertheless1 which is1 to  
convince one's opponents4    ,we1       
therefore1 have experienced great       
satisfaction in learning that we  have  

won over to our ideas an observer of    
singular ability1 on a subject  which is
 of the utmost importance to the        
physiology of cells4                    
,,vi4--,reply to the ,critical          
,observations of ,liebig1 ,published in 
#ahgj4aea      ,in the ,memoir which we 
published1 in #ahfj1 on alcoholic       
fermentation1  and in several subsequent
 works1 we were led to a different      
conclusion  on the causes of this very  
remarkable phenomenon from that which   
,liebig  had adopted4 ,the opinions of  
,mitscherlich and ,berzelius had ceased 
to be  tenable in the presence of the   
new facts which we had brought to light4
  ,from that time we felt sure that the 
celebrated chemist of ,munich had       
adopted our conclusions1 from the fact  
that he remained silent on this         
question for a long time1 although it   
had been until then the constant        
subject of his study1 as is shown by all
 his works4 ,suddenly there  appeared in
 the ,annales de ,chimie et de ,physique

 a long essay1  reproduced from a       
lecture delivered by him before the     
,academy of ,bavaria  in #ahfh and      
#ahfi4 ,in this ,liebig again           
maintained1 not1 however1 without       
certain modifications1 the views which  
he had expressed in his former          
publications1 and disputed the          
correctness of the principal facts      
enunciated in our ,memoir of #ahfj1 on  
which were based the arguments  against 
his theory4    8,i had admitted10 he    
says1 8that the resolution of           
fermentable matter  into compounds of a 
simpler kind must be traced to some     
process of  decomposition taking place  
in the ferment1 and that the action of  
this  same ferment on the fermentable   
matter must continue or cease according 
to the prolongation or cessation of the 
alteration produced in the  ferment4    
,the molecular change in the sugar      
would1 consequently1 be  brought about  
by the destruction or modification of   
one or more of the  component parts of  

the ferment1 and could only take place  
through the  contact of the two         
substances4 ,m4 ,pasteur regards        
fermentation in the  following          
light3--,the chemical action of         
fermentation is essentially a           
phenomenon correlative with a vital     
action1 beginning and ending with  it4  
,he believes that alcoholic fermentation
 can never occur without the            
simultaneous occurrence of organization1
 development1 and multiplication  of    
globules1 or continuous life1 carried on
 from globules already  formed4 ,but the
 idea that the decomposition of sugar   
during fermentation  is due to the      
development of the cellules of the      
ferment1 is in  contradiction with the  
fact that the ferment is able to bring  
about the  fermentation of a pure       
solution of sugar4 ,the greater part of 
the  ferment is composed of a substance 
that is rich in nitrogen and contains   
sulphur4 ,it contains1 moreover1 an     
appreciable quantity of phosphates1     

hence it is difficult to conceive how1  
in the absence of these elements  in a  
pure solution of sugar undergoing       
fermentation1 the number of cells  is   
capable of any increase40               
,notwithstanding ,liebig's belief to the
 contrary1 the idea that the            
decomposition of sugar during           
fermentation is intimately connected    
with  a development of the cellules of  
the ferment1 or a prolongation of the   
life of cellules already formed1 is in  
no way opposed to the fact that  the    
ferment is capable of bringing about the
 fermentation of a pure  solution of    
sugar4 ,it is manifest to any one who   
has studied such  fermentation with the 
microscope1 even in those cases where   
the  sweetened water has been absolutely
 pure1 that ferment-cells do  multiply1 
the reason being that the cells carry   
with them all the  food-supplies        
necessary for the life of the ferment4  
,they may be  observed budding1 at least
 many of them1 and there can be no doubt

 that  those which do not bud still     
continue to live2 life has other ways of
  manifesting itself besides development
 and cell-proliferation4    ,if we refer
 to the figures on page #ha of our      
,memoir of #ahfj1 ,experiments  ,d1 ,e1 
,f1 ,g1 ,h1 ,i1 we shall see that the   
weight of yeast1 in the case of  the    
fermentation of a pure solution of      
sugar1 undergoes a considerable         
increase1 even without taking into      
account the fact that the sugared  water
 gains from the yeast certain soluble   
parts1 since1 in the  experiments just  
mentioned1 the weights of solid yeast1  
washed and dried  at #ajj ,c4 7#bab     
,f471 are much greater than those of the
 raw yeast  employed1 dried at the same 
temperature4    ,in these experiments we
 employed the following weights of      
yeast1  expressed in grammes 7#a gramme 
#aedc grains7--                         
#bcac                                   
#bfbf                                   
#aaih                                   

#jfii                                   
#jcbf                                   
#jdgf    which became after             
fermentation1 we repeat1 without taking 
into account  the matters which the     
sugared water gained from the yeast--   
grammes4 grains4                        
#bdhf   ,increase #jagc   #bfe          
#bifc   8         #jccg   #eaf          
#agjj   0         #jejb   #gg           
#jgab   8         #jjac   #jb           
#jcce   0         #jjji   #jad          
#jeij   8         #jaad   #age    ,have 
we not in this marked increase in weight
 a proof of life1 or1 to  adopt an      
expression which may be preferred1 a    
proof of a profound  chemical work of   
nutrition and assimilation8    ,we may  
cite on this subject one of our earlier 
experiments1 which is to  be found in   
the ,comptes rendus de l',acadmie for   
the year #aheg1 and  which clearly shows
 the great influence exerted on         
fermentation by the  soluble portion    
that the sugared water takes up from the

 globules of  ferment3--    8,we take   
two equal quantities of fresh yeast that
 have been washed very  freely4 ,one of 
these we cause to ferment in water      
containing nothing but  sugar1 and1     
after removing from the other all its   
soluble particles--by  boiling it in an 
excess of water and then filtering it to
 separate the  globules--we add to the  
filtered liquid as much sugar as was    
used in the  first case along with a    
mere trace of fresh yeast1 insufficient1
 as far  as its weight is concerned1 to 
affect the results of our experiment4   
,the  globules which we have sown bud1  
the liquid becomes turbid1 a deposit of 
yeast gradually forms1 and1 side by side
 with these appearances1 the            
decomposition of the sugar is effected1 
and in the course of a few hours        
manifests itself clearly4 ,these results
 are such as we might have  anticipated4
 ,the following fact1 however1 is of    
importance4 ,in effecting  by these     
means the organization into globules of 

the soluble part of the  yeast that we  
used in the second case1 we find that a 
considerable  quantity of sugar is      
decomposed4 ,the following are the      
results of our  experiment3 #e grammes  
of yeast caused the fermentation of #abi
 grammes  of sugar in six days1 at the  
end of which time it was exhausted4 ,the
  soluble portion of a like quantity of 
#e grammes of the same yeast caused  the
 fermentation of #aj grammes of sugar in
 nine days1 after which the  yeast      
developed by the sowing was likewise    
exhausted40    ,how is it possible to   
maintain that1 in the fermentation of   
water  containing nothing but sugar1 the
 soluble portion of the yeast does not  
act1 either in the production of new    
globules or the perfection of old  ones1
 when we see1 in the preceding          
experiment1 that after this  nitrogenous
 and mineral portion has been removed by
 boiling1 it  immediately serves for the
 production of new globules1 which1     
under the  influence of the sowing of a 

mere trace of globules1 causes the      
fermentation of much sugar8#aeb    ,in  
short1 ,liebig is not justified in      
saying that the solution of pure  sugar1
 caused to ferment by means of yeast1   
contains none of the  elements needed   
for the growth of yeast1 neither        
nitrogen1 sulphur1 nor  phosphorus1 and 
that1 consequently1 it should not be    
possible1 by our  theory1 for the sugar 
to ferment4 ,on the contrary1 the       
solution does  contain all these        
elements1 as a consequence of the       
introduction and  presence of the yeast4
    ,let us proceed with our examination
 of ,liebig's criticisms3--    8,to     
this10 he goes on to say1 8must be added
 the decomposing action  which yeast    
exercises on a great number of          
substances1 and which  resembles that   
which sugar undergoes4 ,i have shown    
that malate of lime  ferments readily   
enough through the action of yeast1 and 
that it splits  up into three other     
calcareous salts1 namely the acetate1   

the carbonate1  and the succinate4 ,if  
the action of yeast consists in its     
increase and  multiplication1 it is     
difficult to conceive this action in the
 case of  malate of lime and other      
calcareous salts of vegetable acids40   
,this statement1 with all due deference 
to the opinion of our illustrious       
critic1 is by no means correct4 ,yeast  
has no action on malate of lime1  or on 
other calcareous salts formed by        
vegetable acids4 ,liebig had            
previously1 much to his own             
satisfaction1 brought forward urea as   
being  capable of transformation into   
carbonate of ammonia during alcoholic   
fermentation in contact with yeast4     
,this has been proved by us to be       
erroneous4 ,it is an error of the same  
kind that ,liebig again brings  forward 
here4 ,in the fermentation of which he  
speaks 7that of malate of  lime71       
certain spontaneous ferments are        
produced1 the germs of which are        
associated with the yeast1 and develop  

in the mixture of yeast and  malate4    
,the yeast merely serves as a source of 
food for these new  ferments without    
taking any direct part in the           
fermentations of which we  are speaking4
 ,our researches leave no doubt on this 
point1 as is evident  from the          
observations on the fermentations of    
tartrate of lime  previously given4     
,it is true that there are circumstances
 under which yeast brings about         
modifications in different substances4  
,doebereiner and ,mitscherlich1  more   
especially1 have shown that yeast       
imparts to water a soluble  material1   
which liquefies cane-sugar and produces 
inversion in it by  causing it to take  
up the elements of water1 just as       
diastase behaves to  starch or emulsin  
to amygdalin4    ,m4 ,berthelot also has
 shown that this substance may be       
isolated by  precipitating it with      
alcohol1 in the same way as diastase is 
precipitated from its solutions4#aec    
,these are remarkable facts1 which  are1

 however1 at present but vaguely        
connected with the alcoholic            
fermentation of sugar by means of yeast4
 ,the researches in which we have       
proved the existence of special forms of
 living ferments in many  fermentations1
 which one might have supposed to have  
been produced by  simple contact action1
 had established beyond doubt the       
existence of  profound differences      
between those fermentations1 which we   
have  distinguished as fermentations    
proper1 and the phenomena connected with
  soluble substances4 ,the more we      
advance1 the more clearly we are able to
  detect these differences4 ,m4 ,dumas  
has insisted on the fact that the       
ferments of fermentation proper multiply
 and reproduce themselves in the        
process1 whilst the others are          
destroyed4#aed ,still more recently ,m4 
,mntz has shown that chloroform prevents
 fermentations proper1 but does  not    
interfere with the action of diastase   
7,comptes rendus1 #ahge47 ,m4           

,bouchardat had already established the 
fact that 8hydrocyanic acid1  salts of  
mercury1 ether1 alcohol1 creosote1 and  
the oils of turpentine1  lemon1 cloves1 
and mustard destroy or check alcoholic  
fermentation1  whilst in no way         
interfering with the glucoside          
fermentations0 7,annales  de ,chimie et 
de ,physique1 #crd series1 t4 xiv41     
#ahde47 ,we may add1 in  praise of ,m4  
,bouchardat's sagacity1 that that       
skilful observer has  always considered 
these results as a proof that alcoholic 
fermentation  is dependent on the life  
of the yeast-cell1 and that a           
distinction  should be made between the 
two orders of fermentation4    ,m4 ,paul
 ,bert1 in his remarkable studies on the
 influence of barometric  pressure on   
the phenomena of life1 has recognized   
the fact that  compressed oxygen is     
fatal to certain ferments1 whilst under 
similar  conditions it does not         
interfere with the action of those      
substances  classed under the name of   

soluble ferments1 such as diastase 7the 
ferment which inverts cane sugar71      
emulsin1 and others4 ,during their  stay
 in compressed air1 ferments proper     
ceased their activity1 nor did  they    
resume it1 even after exposure to air at
 ordinary pressures1  provided the      
access of germs was prevented4    ,we   
now come to ,liebig's principal         
objection1 with which he concludes his  
ingenious argument1 and to which no less
 than eight or nine pages of the        
,annales are devoted4    ,our author    
takes up the question of the possibility
 of causing yeast to  grow in sweetened 
water1 to which a salt of ammonia and   
some yeast-ash  have been added--a fact 
which is evidently incompatible with his
 theory  that a ferment is always an    
albuminous substance on its way to      
decomposition4 ,in this case the        
albuminous substance does not exist2 we 
have only the mineral substances which  
will serve to produce it4 ,we know  that
 ,liebig regarded yeast1 and1 generally 

speaking1 any ferment  whatever1 as     
being a nitrogenous1 albuminous         
substance which1 in the  same way as    
emulsin1 for example1 possesses the     
power of bringing about  certain        
chemical decompositions4 ,he connected  
fermentation with the easy              
decomposition of that albuminous        
substance1 and imagined that the        
phenomenon occurred in the following    
manner3--8,the albuminous substance  on 
its way to decomposition possesses the  
power of communicating to  certain other
 bodies that same state of mobility by  
which its own atoms  are already        
affected2 and through its contact with  
other bodies it  imparts to them the    
power of decomposing or of entering into
 other  combinations40 ,here ,liebig    
failed to perceive that the ferment1 in 
its  capacity of a living organism1 had 
anything to do with the fermentation4   
,this theory dates back as far as #ahdc4
 ,in #ahdf ,messrs4 ,boutron and        
,fremy1 in a ,memoir on lactic          

fermentation1 published in the ,annales 
de  ,chimie et de ,physique1 strained   
the conclusions deducible from it to a  
most unjustifiable extent4 ,they        
asserted that one and the same          
nitrogenous substance might undergo     
various modifications in contact  with  
air1 so as to become successively       
alcoholic1 lactic1 butyric1 and  other  
ferments4 ,there is nothing more        
convenient than purely  hypothetical    
theories1 theories which are not the    
necessary consequences  of facts2 when  
fresh facts which cannot be reconciled  
with the original  hypothesis are       
discovered1 new hypotheses can be tacked
 on to the old  ones4 ,this is exactly  
what ,liebig and ,fremy have done1 each 
in his turn1  under the pressure of our 
studies1 commenced in #aheg4 ,in #ahfd  
,fremy  devised the theory of           
hemi-organism1 which meant nothing more 
than  that he gave up ,liebig's theory  
of #ahdc1 together with the additions   
which ,boutron and he had made to it in 

#ahdf2 in other words1 he  abandoned the
 idea of albuminous substances being    
ferments1 to take up  another idea1 that
 albuminous substances1 in contact with 
air1 are  peculiarly adapted to undergo 
organization into new beings--that is1  
the  living ferments which we had       
discovered--and that the ferments of    
beer  and of the grape have a common    
origin4    ,this theory of hemi-organism
 was word for word the antiquated       
opinion of  ,turpin1 as may be readily  
seen by referring to ,chapter ,,iv41    
section ,,iii4  of the present work4    
,the public1 especially a certain       
section of the  public1 did not go very 
deeply into an examination of the       
subject4 ,it  was the period when the   
doctrine of spontaneous generation was  
being  discussed with much warmth4 ,the 
new word hemi-organism1 which was the   
only novelty in ,m4 ,fremy's theory1    
deceived people4 ,it was thought that   
,m4 ,fremy had really discovered the    
solution of the question of the day4    

,it is true that it was rather difficult
 to understand the process by  which an 
albuminous substance could become all at
 once a living and  budding cell4 ,this 
difficulty was readily solved by ,m4    
,fremy1 who  declared that it was the   
result of some power that was not yet   
understood1 the power of 8organic       
impulse40#aee    ,liebig1 who1 as well  
as ,m4 ,fremy1 was compelled to renounce
 his original  opinions concerning the  
nature of ferments1 devised the         
following  obscure theory 7,memoir by   
,liebig1 #ahgj1 already cited73--       
8,there seems to be no doubt as to the  
part which the vegetable organism  plays
 in the phenomenon of fermentation4 ,it 
is through it alone that an  albuminous 
substance and sugar are enabled to unite
 and form this  particular combination1 
this unstable form under which alone1 as
 a  component part of the mycoderm1 they
 manifest an action on sugar4 ,should   
the mycoderm cease to grow1 the bond    
which unites the constituent parts  of  

the cellular contents is loosened1 and  
it is through the motion  produced      
therein that the cells of yeast bring   
about a disarrangement or  separation of
 the elements of the sugar into other   
organic molecules40    ,one might easily
 believe that the translator for the    
,annales has made  some mistake1 so     
great is the obscurity of this passage4 
,whether we take this new form of the   
theory or the old one1 neither can  be  
reconciled at all with the development  
of yeast and fermentation in a          
saccharine mineral medium1 for in the   
latter experiment fermentation is       
correlative to the life of the ferment  
and to its nutrition1 a constant  change
 going on between the ferment and its   
food-matters1 since all the  carbon     
assimilated by the ferment is derived   
from sugar1 its nitrogen  from ammonia1 
and phosphorus from the phosphates in   
solution4 ,and even  all said1 what     
purpose can be served by the gratuitous 
hypothesis of  contact-action or        

communicated motion8 ,the experiment of 
which we are  speaking is thus a        
fundamental one2 indeed1 it is its      
possibility that  constitutes the most  
effective point in the controversy4 ,no 
doubt ,liebig  might say1 8but it is the
 motion of life and of nutrition which  
constitutes your experiment1 and this is
 the communicated motion that my  theory
 requires40 ,curiously enough1 ,liebig  
does endeavour1 as a matter  of fact1 to
 say this1 but he does so timidly and   
incidentally3 8,from a  chemical point  
of view1 which point of view ,i would   
not willingly  abandon1 a vital action  
is a phenomenon of motion1 and1 in this 
double  sense of life ,m4 ,pasteur's    
theory agrees with my own1 and is not in
  contradiction with it 7page #f740     
,this is true4 ,elsewhere ,liebig       
says3--    8,it is possible that the    
only correlation between the            
physiological act  and the phenomenon of
 fermentation is the production1 in the 
living  cell1 of the substance which1 by

 some special property analogous to that
  by which emulsin exerts a decomposing 
action on salicin and amygdalin1  may   
bring about the decomposition of sugar  
into other organic molecules2  the      
physiological act1 in this view1 would  
be necessary for the  production of this
 substance1 but would have nothing else 
to do with the  fermentation 7page      
#aj740 ,to this1 again1 we have no      
objection to raise4    ,liebig1 however1
 does not dwell upon these              
considerations1 which he  merely notices
 in passing1 because he is well aware   
that1 as far as the  defence of his     
theory is concerned1 they would be mere 
evasions4 ,if he  had insisted on them1 
or based his opposition solely upon     
them1 our  answer would have been simply
 this3 8,if you admit with us that      
fermentation is correlated with the life
 and nutrition of the ferment1  we agree
 upon the principal point4 ,so agreeing1
 let us examine1 if you  will1 the      
actual cause of fermentation2--this is a

 second question1 quite  distinct from  
the first4 ,science is built up of      
successive solutions  given to questions
 of ever-increasing subtlety1           
approaching nearer and  nearer towards  
the very essence of phenomena4 ,if we   
proceed to discuss  together the        
question of how living1 organized beings
 act in decomposing  fermentable        
substances1 we will be found to fall out
 once more on your  hypothesis of       
communicated motion1 since1 according to
 our ideas1 the  actual cause of        
fermentation is to be sought1 in most   
cases1 in the fact  of life without air1
 which is the characteristic of many    
ferments40    ,let us briefly see what  
,liebig thinks of the experiment in     
which  fermentation is produced by the  
impregnation of a saccharine mineral    
medium1 a result so greatly at variance 
with his mode of viewing the            
question4#aef ,after deep consideration 
he pronounces this experiment to  be    
inexact1 and the result ill-founded4    

,liebig1 however1 was not one to  reject
 a fact without grave reasons for his   
doing so1 or with the sole  object of   
evading a troublesome discussion4 8,i   
have repeated this  experiment10 he     
says1 8a great number of times1 with the
 greatest  possible care1 and have      
obtained the same results as ,m4        
,pasteur1  excepting as regards the     
formation and increase of the ferment40 
,it was1  however1 the formation and    
increase of the ferment that constituted
 the  point of the experiment4 ,our     
discussion was1 therefore1 distinctly   
limited to this3 ,liebig denied that the
 ferment was capable of  development in 
a saccharine mineral medium1 whilst we  
asserted that this  development did     
actually take place1 and was            
comparatively easy to  prove4 ,in #ahga 
we replied to ,m4 ,liebig before the    
,paris ,academy of  ,sciences in a      
,note1 in which we offered to prepare in
 a mineral medium1  in the presence of a
 commission to be chosen for the        

purpose1 as great a  weight of ferment  
as ,liebig could reasonably demand4#aeg 
,we were bolder  than we should1        
perhaps1 have been in #ahfj2 the reason 
was that our  knowledge of the subject  
had been strengthened by ten years of   
renewed  research4 ,liebig did not      
accept our proposal1 nor did he even    
reply to  our ,note4 ,up to the time of 
his death1 which took place on ,april   
#ahth1  #ahgc1 he wrote nothing more on 
the subject4#aeh    ,when we published1 
in #ahfj1 the details of the experiment 
in question1  we pointed out at some    
length the difficulties of conducting it
  successfully1 and the possible causes 
of failure4 ,we called attention        
particularly to the fact that saccharine
 mineral media are much more  suited for
 the nutrition of bacteria1 lactic      
ferment1 and other lowly  forms1 than   
they are to that of yeast1 and in       
consequence readily become  filled with 
various organisms from the spontaneous  
growth of germs  derived from the       

particles of dust floating in the       
atmosphere4 ,the  reason why we do not  
observe the growth of alcoholic         
ferments1  especially at the            
commencement of the experiments1 is     
because of the  unsuitableness of those 
media for the life of yeast4 ,the latter
 may1  nevertheless1 form in them       
subsequent to this development of other 
organized forms1 by reason of the       
modification produced in the original   
mineral medium by the albuminous matters
 that they introduce into it4 ,it  is   
interesting to peruse1 in our ,memoir of
 #ahfj1 certain facts of the  same kind 
relating to fermentation by means of    
albumens--that of the  blood1 for       
example1 from which1 we may mention     
incidentally1 we were led  to infer the 
existence of several distinct albumens  
in the serum1 a  conclusion which1 since
 then1 has been confirmed by various    
observers1  notably by ,m4 ,bchamp4     
,now1 in his experiments on fermentation
 in  sweetened water1 with yeast-ash and

 a salt of ammonia1 there is no doubt   
that ,liebig had failed to avoid those  
difficulties which are entailed by  the 
spontaneous growth of other organisms   
than yeast4 ,moreover1 it is  possible  
that1 to have established the certainty 
of this result1 ,liebig  should have had
 recourse to a closer microscopical     
observation than from  certain passages 
in his ,memoir he seems to have adopted4
 ,we have little  doubt that his pupils 
could tell us that ,liebig did not even 
employ that  instrument without which   
any exact study of fermentation is not  
merely  difficult but well-nigh         
impossible4 ,we ourselves1 for the      
reasons  mentioned1 did not obtain a    
simple alcoholic fermentation any more  
than  ,liebig did4 ,in that particular  
experiment1 the details of which we gave
  in our ,memoir of #ahfj1 we obtained  
lactic and alcoholic fermentation       
together2 an appreciable quantity of    
lactic acid formed and arrested the     
propagation of the lactic and alcoholic 

ferments1 so that more than half  of the
 sugar remained in the liquid without   
fermenting4 ,this1 however1  in no way  
detracted from the correctness of the   
conclusion which we  deduced from the   
experiment1 and from other similar ones2
 it might even  be said that1 from a    
general and philosophical point of      
view--which is  the only one of interest
 here--the result was doubly            
satisfactory1  inasmuch as we           
demonstrated that mineral media were    
adapted to the  simultaneous development
 of several organized ferments1 instead 
of only  one4 ,the fortuitous           
association of different ferments could 
not  invalidate the conclusion that all 
the nitrogen of the cells of the        
alcoholic and lactic ferments was       
derived from the nitrogen in the        
ammoniacal salts1 and that all the      
carbon of those ferments was taken  from
 the sugar1 since1 in the medium        
employed in our experiment1 the  sugar  
was the only substance that contained   

carbon4 ,liebig carefully  abstained    
from noticing this fact1 which would    
have been fatal to the  very groundwork 
of his criticisms1 and thought that he  
was keeping up  the appearance of a     
grave contradiction by arguing that we  
had never  obtained a simple alcoholic  
fermentation4 ,it would be unprofitable 
to  dwell longer upon the subject of the
 difficulties which the propagation  of 
yeast in a saccharine mineral medium    
formerly presented4 ,as a matter  of    
fact1 the progress of our studies has   
imparted to the question an  aspect very
 different from that which it formerly  
wore2 it was this  circumstance which   
emboldened us to offer1 in our reply to 
,liebig before  the ,academy of         
,sciences in #ahga1 to prepare1 in a    
saccharine mineral  medium1 in the      
presence of a commission to be appointed
 by our opponent1  any quantity of      
ferment that he might require1 and to   
effect the  fermentation of any weight  
of sugar whatsoever4    ,our knowledge  

of the facts detailed in the preceding  
chapters concerning  pure ferments and  
their manipulation in the presence of   
pure air1  enables us to completely     
disregard those causes of embarrassment 
that  result from the fortuitous        
occurrence of the germs of organisms1   
different in character from the         
ferments1 introduced by the air or from 
the sides of vessels1 or even by the    
ferment itself4    ,let us once more    
take one of our double-necked flasks    
7,fig4 #bb1 p4 #aaj71  which we will    
suppose is capable of containing three  
or four litres 7six  to eight pints74   
,let us put into it the following3--    
,pure distilled                         
water4                       ,sugar     
candy          #bjj grammes4            
,bitartrate of        #aj  8            
potassium                       0      8
  ammonia    #je  0                     
,sulphate of ammonia  #ae  8            
,ash of yeast         #ae  0            
#a gramme  #aedc                        

grains4    ,let us boil the mixture1 to 
destroy all germs of organisms that may 
exist in the air or liquid or on the    
sides of the flask1 and then permit  it 
to cool1 after having placed1 by way of 
extra precaution1 a small  quantity of  
asbestos in the end of the fine1 curved 
tube4 ,let us next  introduce a trace of
 ferment into the liquid1 through the   
other neck1  which1 as we described1 is 
terminated by a small piece of          
india-rubber  tube closed with a glass  
stopper4    ,here are the details of    
such an experiment3--    ,on ,december  
#i1 #ahgc1 we sowed some pure           
ferment--saccharomyces  pastorianus4    
,from ,december #aa1 that is1 within so 
short a time as  forty-eight hours after
 impregnation1 we saw a multitude of    
extremely  minute bubbles rising almost 
continuously from the bottom1 indicating
  that at this point the fermentation   
had commenced4 ,on the following  days1 
several patches of froth appeared on the
 surface of the liquid4 ,we  left the   

flask undisturbed in the oven1 at a     
temperature of #be ,c4 7#gg  ,f474 ,on  
,april #bd1 #ahgd1 we tested some of the
 liquid1 obtained by means  of the      
straight tube1 to see if it still       
contained any sugar4 ,we found  that it 
contained less than two grammes1 so that
 #aih grammes 7#db oz4  ,troy7 had      
already disappeared4 ,some time         
afterwards the fermentation  came to an 
end2 we carried on the experiment1      
nevertheless1 until ,april  #ah1 #ahge4 
,there was no development of any        
organism absolutely foreign to the      
ferment1 which was itself abundant1 a   
circumstance that1 added to the         
persistent vitality of the ferment1 in  
spite of the unsuitableness of  the     
medium for its nutrition1 permitted the 
perfect completion of  fermentation4    
,there was not the minutest quantity of 
sugar remaining4  ,the total weight of  
ferment1 after washing and drying at    
#ajj ,c4 7#bab  ,f471 was #befc grammes 
7#cie grains74    ,in experiments of    

this kind1 in which the ferment has to  
be weighed1 it  is better not to use any
 yeast-ash that cannot be dissolved     
completely1  so as to be capable of easy
 separation from the ferment formed4    
,raulin's  liquid1 the composition of   
which we have already given 7p4 #hi1    
footnote71 may be used in such cases    
with success4    ,all the alcoholic     
ferments are not capable to the same    
extent of  development by means of      
phosphates1 ammoniacal salts1 and sugar4
 ,there  are some whose development is  
arrested a longer or shorter time before
  the transformation of all the sugar4  
,in a series of comparative             
experiments1 #bjj grammes of sugar-candy
 being used in each case1 we  found that
 whilst saccharomyces pastorianus       
effected a complete  fermentation of the
 sugar1 the caseous ferment did not     
decompose more  than two-thirds1 and the
 ferment which we have designated new   
8high0  ferment not more than one-fifth3
 and keeping the flasks for a longer    

time in the oven had no effect in       
increasing the proportions of sugar     
fermented in these two last cases4      
,we conducted a great number of         
fermentations in mineral media1 in      
consequence of a circumstance which it  
may be interesting to mention  here4 ,a 
person who was working in our laboratory
 asserted that the  success of our      
experiments depended upon the impurity  
of the sugar-candy  which we employed1  
and that if this sugar had been         
pure--much purer than  was the ordinary1
 white1 commercial sugar-candy1 which up
 to that time  we had always used--the  
ferment could not have multiplied4 ,the 
persistent  objections of our friend1   
and our desire to convince him1 caused  
us to  repeat all our previous          
experiments on the subject1 using sugar 
of great  purity1 which had been        
specially prepared for us1 with the     
utmost care1  by a skilful confectioner1
 ,seugnot4 ,the result only confirmed   
our former  conclusions4 ,even this did 

not satisfy our obstinate friend1 who   
went to  the trouble of preparing some  
pure sugar for himself1 in little       
crystals1 by repeated crystallizations  
of carefully-selected commercial        
sugar-candy2 he then repeated our       
experiments himself4 ,this time all his 
doubts were overcome4 ,it even happened 
that the fermentations with the         
perfectly pure sugar instead of being   
slow were very active1 when  compared   
with those which we had conducted with  
the commercial  sugar-candy4    ,we may 
here add a few words on the             
non-transformation of yeast into        
penicillium glaucum4    ,if at any time 
during fermentation we pour off the     
fermenting liquid1  the deposit of yeast
 remaining in the vessel may continue   
there1 in  contact with air1 without our
 ever being able to discover the least  
formation of penicillium glaucum in it4 
,we may keep a current of pure  air     
constantly passing through the flask2   
the experiment will give the  same      

result4 ,nevertheless1 this is a medium 
peculiarly adapted to the  development  
of this mould1 inasmuch as if we        
introduce merely a few  spores of       
penicillium1 an abundant vegetation of  
that growth will  afterwards appear on  
the deposit4 ,the descriptions of       
,messrs4 ,turpin1  ,hoffmann1 and ,trcul
 have1 therefore1 been based on one of  
these  illusions which we meet with so  
frequently in microscopical             
observations4 ,when we laid these facts 
before the ,academy1#aei ,m4  ,trcul    
professed his inability to comprehend   
them3#afj    8,according to ,m4         
,pasteur10 he said1 8the yeast of beer  
is anarobian1  that is to say1 it lives 
in a liquid deprived of free oxygen2 and
 to  become mycoderma or penicillium it 
is above all things necessary  that it  
should be placed in air1 since1 without 
this1 as the name  signifies1 an arobian
 being cannot exist4 ,to bring about the
  transformation of the yeast of beer   
into mycoderma cerevisi or into         

penicillium glaucum1 we must accept the 
conditions under which these  two forms 
are obtained4 ,if ,m4 ,pasteur will     
persist in keeping his yeast  in media  
which are incompatible with the desired 
modification1 it is  clear that the     
results which he obtains must be always 
negative40    ,contrary to this         
perfectly gratuitous assertion of ,m4   
,trcul's1 we do  not keep our yeast in  
media which are calculated to prevent   
its  transformation into penicillium4   
,as we have just seen1 the principal    
aim and object of our experiment was to 
bring this minute plant into  contact   
with air1 and under conditions that     
would allow the  penicillium to develop 
with perfect freedom4 ,we conducted our 
experiments exactly as ,turpin and      
,hoffmann conducted theirs1 and exactly 
as they stipulate that such experiments 
should be conducted--with the one  sole 
difference1 indispensable to the        
correctness of our observations1  that  
we carefully guarded ourselves against  

those causes of error which  they did   
not take the least trouble to avoid4 ,it
 is possible to produce  a ready        
entrance and escape of pure air in the  
case of the double-necked  flasks which 
we have so often employed in the course 
of this work1  without having recourse  
to the continuous passage of a current  
of air4  ,having made a file-mark on the
 thin curved neck at a distance of two  
or  three centimetres 7an inch7 from the
 flask1 we must cut round the neck  at  
this point with a glazier's diamond1 and
 then remove it1 taking care  to cover  
the opening immediately with a sheet of 
paper which has been  passed through the
 flame1 and which we must fasten with a 
thread round  the part of the neck still
 left4 ,in this manner we may increase  
or  prolong the fructification of       
fungoid growths1 or the life of arobian 
ferments in our flasks4    ,what we have
 said of penicillium glaucum will apply 
equally to  mycoderma cerevisi4         
,notwithstanding what ,turpin and ,trcul

 may assert  to the contrary1 yeast1 in 
contact with air as it was under the    
conditions of the experiment just       
described1 will not yield mycoderma     
vini or mycoderma cerevisi any more than
 it will penicillium4    ,the           
experiments described in the preceding  
paragraphs on the increase of  organized
 ferments in mineral media of the       
composition described1 are of  great    
physiological interest4 ,amongst other  
results1 they show that all  the proteic
 matter of ferments may be produced by  
the vital activity of  the cells1 which1
 apart altogether from the influence of 
light or free  oxygen 7unless1 indeed1  
we are dealing with arobian moulds which
  require free oxygen71 have the power  
of developing a chemical activity       
between carbo-hydrates1 ammoniacal      
salts1 phosphates and sulphates of      
potassium and magnesium4 ,it may be     
admitted with truth that a similar      
effect obtains in the case of the higher
 plants1 so that in the existing  state 

of science we fail to conceive what     
serious reason can be urged  against our
 considering this effect as general4 ,it
 would be perfectly  logical to extend  
the results of which we are speaking to 
all plants1  and to believe that the    
proteic matter of vegetables1 and       
perhaps of  animals also1 is formed     
exclusively by the activity of the cells
  operating upon the ammoniacal and     
other mineral salts of the sap or       
plasma of the blood1 and the            
carbo-hydrates1 the formation of which1 
in  the case of the higher plants1      
requires only the concurrence of the    
chemical impulse of green light4        
,viewed in this manner1 the formation of
 the proteic substances would be        
independent of the great act of         
reduction of carbonic acid gas under the
  influence of light4 ,these substances 
would not be built up from the  elements
 of water1 ammonia1 and carbonic acid   
gas1 after the  decomposition of this   
last2 they would be formed where they   

are found in  the cells themselves1 by  
some process of union between the       
carbo-hydrates imported by the sap1 and 
the phosphates of potassium and         
magnesium and salts of ammonia4 ,lastly1
 in vegetable growth1 by means of  a    
carbo-hydrate and a mineral medium1     
since the carbo-hydrate is capable  of  
many variations1 and it would be        
difficult to understand how it could  be
 split up into its elements before      
serving to constitute the proteic       
substances1 we may hope to obtain as    
many distinct proteic substances1  and  
even cellulose substances1 as there are 
carbo-hydrates4 ,we have  commenced     
certain studies in this direction4      
,if solar radiation is indispensable to 
the decomposition of carbonic  acid and 
the building up of the primary          
substances in the case of  higher       
vegetable life1 it is still possible    
that certain inferior  organisms may do 
without it and nevertheless yield the   
most complex  substances1 fatty or      

carbo-hydrate1 such as cellulose1       
various organic  acids1 and proteic     
matter2 not1 however1 by borrowing their
 carbon  from the carbonic acid which is
 saturated with oxygen1 but from other  
matters still capable of acquiring      
oxygen1 and so of yielding heat in  the 
process1 such as alcohol and acetic     
acid1 for example1 to cite  merely      
carbon compounds most removed from      
organization4 ,as these last  compounds1
 and a host of others equally adapted to
 serve as the  carbonaceous food of     
mycoderms and the mucedines1 may be     
produced  synthetically by means of     
carbon and the vapour of water1 after   
the  methods that science owes to       
,berthelot1 it follows that1 in the case
  of certain inferior beings1 life would
 be possible even if it should  be that 
the solar light was extinguished4#afa   
,footnote #aaa3      ,it has been       
remarked in practice that fermentation  
is facilitated by    leaving the grapes 
on the bunches4 ,the reason of this has 

not yet been    discovered4 ,still we   
have no doubt that it may be attributed1
    principally1 to the fact that the   
interstices between the grapes1 and     
the spaces which the bunch leaves       
throughout1 considerably increase    the
 volume of air placed at the service of 
the germs of ferment4    ,footnote #aab3
      ,na,h,s,o#b1 now called ,sodium   
hyposulphite4 ,see p4 #cee1             
footnote4--,d4,c4,r4    ,footnote #aac3 
,this appears to be a misprint for #afch
 grammes  #bec    grains4--,d4,c4,r4    
,footnote #aad3      #bjj c4c4 of liquid
 were used1 which1 as containing #e per 
cent41 had    in solution #aj grammes of
 sugar4--,d4 ,c4 ,r4    ,footnote #aae3 
,international ,science ,series1 vol4   
xx41 pp4 #agi-ahb4 ,london1 #ahgf4--;,d4
    ,c4 ,r4    ,footnote #aaf3          
,page #ahb1 ,english edition4           
,footnote #aag3      ,this figure is on 
a scale of #cjj diameters1 most of the  
figures in    this work being of #djj   
diameters4    ,footnote #aah3      ,it  

may be useful for the non-scientific    
reader to put it thus3--that    the #be 
c4c4 which escaped1 being a fair sample 
of the whole gas in the    flask1 and   
containing 7#a7 #be - #bjf  #dd c4c41   
absorbed by potash and    therefore due 
to carbonic acid1 and 7#b7 #bjf - #agc  
#cc c4c41    absorbed by pyrogallate1   
and therefore due to oxygen1 and the    
remaining #agc c4c4 being nitrogen1 the 
whole gas in the flask1 which    has a  
capacity of #cae c4c41 will contain     
oxygen in the above    proportion1 and  
therefore its amount may be determined1 
provided we    know the total gas in the
 flask before opening4 ,on the other    
hand1 we    know that air normally      
contains1 approximately1 #a_/eth its    
volume of    oxygen1 the rest being     
nitrogen1 so that1 by ascertaining the  
diminution of the proportion in the     
flask1 we can find how many cubic       
centimetres have been absorbed by the   
yeast4 ,the author1 however1 has    not 
given all the data necessary for        

accurate calculation4--,d4,c4,r4        
,footnote #aai3      ,this number is    
probably too small2 it is scarcely      
possible that the    increase of weight 
in the yeast1 even under the exceptional
 conditions    of the experiment        
described1 was not to some extent at    
least due to    oxidation apart from    
free oxygen1 inasmuch as some of the    
cells were    covered by others4 ,the   
increased weight of the yeast is always 
due to    the action of two distinct    
modes of vital energy--activity1 namely1
 in    presence and activity in absence 
of air4 ,we might endeavour to shorten  
the duration of the experiment still    
further1 in which case we would    still
 more assimilate the life of the yeast  
to that of ordinary    moulds4          
,footnote #abj3      ,in these          
experiments1 in which the moulds remain 
for a long time in    contact with a    
saccharine wort out of contact with     
oxygen--the oxygen    being promptly    
absorbed by the vital action of the     

plant 7see our    ,mmoire sur les       
,gnrations dites ,spontanes1 p4 #ed1    
note7--there is    no doubt that an     
appreciable quantity of alcohol is      
formed because the    plant does not    
immediately lose its vital activity1    
after the    absorption of oxygen4      
,a #cjj-;c4c4 7#aj-oz47 flask1          
containing #ajj c4c4 of must1 after the 
air    in it had been expelled by       
boiling1 was opened and immediately     
re-closed1 on ,august #aeth1 #ahgc4 ,a  
fungoid growth--a unique one1 of        
greenish-grey colour--developed from    
spontaneous impregnation1 and           
decolorized the liquid1 which originally
 was of a yellowish-brown4    ,some     
large crystals1 sparkling like diamonds1
 of neutral tartrate of    lime1 were   
precipitated4 ,about a year afterwards1 
long after the death    of the plant1 we
 examined this liquid4 ,it contained #jc
 gramme 7#df    grains7 of alcohol1 and 
#jjec gramme 7#jh grain7 of vegetable   
matter1    dried at #ajj ,c4 7#bab ,f474

 ,we ascertained that the spores of the 
fungus were dead at the moment when the 
flask was opened4 ,when sown1    they   
did not develop in the least degree4    
,footnote #aba3      ,we find in ,m4    
,raulin's ,note1 already quoted1 that   
8the minimum ratio    between the weight
 of sugar and the weight of organized   
matter1 that    is1 the weight of       
fungoid growth which it helps to form1  
may be    expressed #aj_/cb  #ca40      
,,jules ,,raulin1 tudes chimiques sur la
    vgtation4 ,recherches sur le        
dveloppement d'une mucdine dans un      
milieu artificiel1 p4 #aib1 ,paris1     
#ahgj4 ,we have seen1 in the case of    
yeast1 that this ratio may be as low as 
#d_/a4    ,footnote #abb3      ,we shall
 show1 some day1 that the processes of  
oxidation due to growth    of fungi     
cause1 in certain decompositions1       
liberation of ammonia to a              
considerable extent1 and that by        
regulating their action we might        
cause them to extract the nitrogen from 

a host of organic dbris1 as    also1 by 
checking the production of such         
organisms1 we might    considerably     
increase the proportion of nitrates in  
the artificial    nitrogenous           
substances4 ,by cultivating various     
moulds on the surface    of damp bread  
in a current of air1 we have obtained an
 abundance of    ammonia1 derived from  
the decomposition of the albuminoids    
effected by    the fungoid life4 ,the   
decomposition of asparagus1 and several 
other    animal or vegetable substances1
 has given similar results4    ,footnote
 #abc3      ,to determine the absence of
 cells of ferment in fruits that have   
been    immersed in carbonic acid gas1  
we must first of all carefully raise    
the pellicle of the fruit1 taking care  
that the subjacent parenchyma    does   
not touch the surface of the pellicle1  
since the organized    corpuscles       
existing on the exterior of the fruit   
might introduce an    error into our    
microscopical observations4 ,experiments

 on grapes have    given us an          
explanation of a fact generally known1  
the cause of which1    however1 had     
hitherto escaped our knowledge4 ,we all 
know that the    taste and aroma of the 
vintage1 that is1 of the grapes stripped
 from    the bunches and thrown into    
tubs1 where they get soaked in the juice
    that issues from wounded specimens1 
are very different from the taste    and
 aroma of an uninjured bunch4 ,now      
grapes that have been immersed in    an 
atmosphere of carbonic acid gas have    
exactly the flavour and smell    of the 
vintage2 the reason is that1 in the     
vintage tub1 the grapes are             
immediately surrounded by an atmosphere 
of carbonic acid gas1 and    undergo1 in
 consequence1 the fermentation peculiar 
to grapes that have    been plunged in  
this gas4 ,these facts deserve to be    
studied from a    practical point of    
view4 ,it would be interesting1 for     
example1 to    learn what difference    
there would be in the quality of two    

wines1 the    grapes of which1 in the   
one case1 had been perfectly crushed1 so
 as to    cause as great a separation of
 the cells of the parenchyma as         
possible2 in the other case1 left1 for  
the most part1 whole1 as in the    case 
in the ordinary vintage4 ,the first wine
 would be deprived of    those fixed and
 fragrant principles produced by the    
fermentation of    which we have just   
spoken1 when the grapes are immersed in 
carbonic    acid gas4 ,by such a        
comparison as that which we suggest1 we 
should be    able to form an  priori    
judgment on the merits of the new       
system1    which has not been carefully 
studied1 although already widely        
adopted1    of milled1 cylindrical      
crushers1 for pressing the vintage4     
,footnote #abd3      ,we have sometimes 
found small quantities of alcohol in    
fruits and    other vegetable organs1   
surrounded with ordinary air1 but always
 in    small proportion1 and in a manner
 which suggested its accidental         

character4 ,it is easy to understand    
how1 in the thickness of certain        
fruits1 certain parts of those fruits   
might be deprived of air1 under    which
 circumstance they would have been      
acting under conditions    similar to   
those under which fruits act when wholly
 immersed in    carbonic acid gas4      
,moreover it would be useful to         
determine whether    alcohol is not a   
normal product of vegetation4           
,footnote #abe3      ,in these studies  
on plants living immersed in carbonic   
acid gas1 we    have come across a fact 
which corroborates those which we have  
already    given in reference to the    
facility with which lactic and viscous  
ferments1 and1 generally speaking1 those
 which we have termed the               
disease-ferments of beer1 develop when  
deprived of air1 and which    shows1    
consequently1 how very marked their     
arobian character is4 ,if    we immerse 
beetroots or turnips in carbonic acid   
gas1 we produce    well-defined         

fermentations in those roots4 ,their    
whole surface readily    permits the    
escape of the highly acid liquids1 and  
they become filled    with lactic1      
viscous1 and other ferments4 ,this shows
 us the great    danger which may result
 from the use of pits1 in which the     
beetroots    are preserved1 when the air
 is not renewed1 and that the original  
oxygen is expelled by the vital         
processes of fungi1 or other            
deoxidizing chemical actions4 ,we have  
directed the attention of the           
manufacturers of beetroot sugar to this 
point4    ,footnote #abf3               
,,lechartier and ,,bellamy1 ,comptes    
rendus de l',acadmie des ,sciences1     
vol4 lxix41 pp4 #cff and #dff1 #ahfi4   
,footnote #abg3      ,those gentlemen   
express themselves thus3 8,in a note    
presented to the    ,academy in         
,november1 #ahgb1 we published certain  
experiments which    showed that        
carbonic acid and alcohol may be        
produced in fruits kept    in a closed  

vessel1 out of contact with atmospheric 
oxygen1 without    our being able to    
discover alcoholic ferment in the       
interior of those    fruits4      8,m4  
,pasteur1 as a logical deduction from   
the principles which he has             
established in connection with the      
theory of fermentation1 considers       
that the formation of alcohol may be    
attributed to the fact that the         
physical and chemical processes of life 
in the cells of fruit continue    under 
new conditions1 in a manner similar to  
those of the cells of    ferment4       
,experiments1 continued during #ahgb1   
#ahgc1 and #ahgd1 on    different       
fruits1 have furnished results all of   
which seem to us to    harmonize with   
this proposition1 and to establish it on
 a firm basis    of proof40 ,comptes    
rendus1 t4 lxxix41 p4 #idi1 #ahgd4      
,footnote #abh3      ,,pasteur1 ,faites 
nouveaux pour servir  la connaissance de
 la thorie    des fermentations         
proprement dites4 7,comptes rendus de   

l',acadmie    des ,sciences1 t4 lxxv41  
p4 #ghd74 ,see1 in the same volume1 the 
discussion that followed2 also1         
,,pasteur1 ,note sur la production de   
l'alcool par les fruits1 same volume1 p4
 #ajed1 in which we recount    the      
observations anterior to our own1 made  
by ,messrs4 ,lechartier and    ,bellamy 
in #ahfi4    ,footnote #abi3            
,comptes rendus1 meeting of ,january    
#aeth1 #ahgb4    ,footnote #acj3        
,as a matter of fact1 ,m4 ,fremy applies
 his theory of hemi-organism1 not       
only to the alcoholic fermentation of   
grape juice1 but to all other           
fermentations4 ,the following passage   
occurs in one of his ,notes    7,comptes
 rendus de l',acadmie1 t4 lxxv41 p4     
#igi1 ,october #bhth1    #ahgb73        
8,experiments on ,germinated            
,barley4--,the object of these was to   
show    that1 when barley1 left to      
itself in sweetened water1 produces in  
succession alcoholic1 lactic1 butyric1  
and acetic fermentations1 these         

modifications are brought about by      
ferments which are produced inside      
the grains themselves1 and not by       
atmospheric germs4 ,more than forty     
different experiments were devoted to   
this part of my work40 ,need we    add  
that this assertion is based on no      
substantial foundation8 ,the    cells   
belonging to the grains of barley1 or   
their albuminous contents1    never do  
produce cells of alcoholic ferment1 or  
of lactic ferment1 or    butyric        
vibrios4 ,whenever those ferments appear
 they may be traced to    germs of those
 organisms1 diffused throughout the     
interior of the    grains1 or adhering  
to their exterior surface1 or existing  
in the    water employed1 or on the     
sides of the vessels used4 ,there are   
many    ways of demonstrating this1 of  
which the following is one3 since the   
results of our experiments have shown   
that sweetened water1    phosphates1 and
 chalk very readily give rise to lactic 
and butyric    fermentations1 what      

reason is there for supposing that if we
    substitute grains of barley for     
chalk1 the lactic and butyric ferments  
will spring from those grains1 in       
consequence of a transformation of      
their cells or albuminous substances8   
,surely1 there is no ground for         
maintaining that they are produced by   
hemi-organism1 since a medium           
composed of sugar1 or chalk1 or         
phosphates of ammonia1 potash1 or       
magnesia contains no albuminous         
substances4 ,this is an indirect but    
irresistible argument against the       
hemi-organism theory4    ,footnote #aca3
      ,,pasteur1 ,mmoire sur la         
fermentation alcoolique1 #ahfj2 ,annales
 de    ,chimie et de ,physique4 ,the    
word globules is here used for cells4   
,in our researches we have always       
endeavoured to prevent any confusion    
of ideas4 ,we stated at the beginning of
 our ,memoir of #ahfj1 that3 8,we       
apply the term alcoholic to that        
fermentation which sugar undergoes      

under the influence of the ferment known
 as beer yeast40 ,this is the           
fermentation which produces wine and all
 alcoholic beverages4 ,this1    too1 is 
regarded as the type for a host of      
similar phenomena1    designated1 by    
general usage1 under the generic name of
    fermentation1 and qualified by the  
name of one of the essential    products
 of the special phenomenon under        
observation4 ,bearing in mind    this   
fact in reference to the nomenclature   
that we have adopted1 it    will be seen
 that the expression alcoholic          
fermentation cannot be    applied to    
every phenomenon of fermentation in     
which alcohol is    produced1 inasmuch  
as there may be a number of phenomena   
having this    character in common4 ,if 
we had not at starting defined that     
particular    one amongst the number of 
very distinct phenomena1 which1 to the  
exclusion of the others1 should bear the
 name alcoholic    fermentation1 we     
should inevitably have given rise to a  

confusion of    language that would soon
 pass from words to ideas1 and tend to  
introduce unnecessary complexity into   
researches which are already1 in        
themselves1 sufficiently complex to     
necessitate the adoption of             
scrupulous care to prevent their        
becoming still more involved4 ,it       
seems to us that any further doubt as to
 the meaning of the words    alcoholic  
fermentation1 and the sense in which    
they are employed1 is    impossible1    
inasmuch as ,lavoisier1 ,gay-,lussac1   
and ,thnard have    applied this term to
 the fermentation of sugar by means of  
beer yeast4    ,it would be both        
dangerous and unprofitable to discard   
the example set    by those illustrious 
masters1 to whom we are indebted for our
 earliest    knowledge of this subject4 
,footnote #acb3      ,see1 for example1 
the communications of ,,mm4 ,colin and  
,poggiale1 and    the discussion on     
them1 in the ,bulletin de l',acadmie de 
,mdicine1    ,march #bnd1 #ith1 and     

#cjth1 and ,february #afth and #bcrd1   
#ahge4    ,footnote #acc3      ,we have 
elsewhere determined the formation of   
minute quantities of    volatile acids  
in alcoholic fermentation4 ,m4 ,bchamp1 
who studied    these1 recognized several
 belonging to the series of fatty acids1
    acetic acid1 butyric acid1 c4 8,the 
presence of succinic acid is not        
accidental1 but constant2 if we put     
aside volatile acids that form in       
quantities which we may call infinitely 
small1 we may say that    succinic acid 
is the only normal acid of alcoholic    
fermentation40    ,,pasteur1 ,comptes   
rendus de l',acadmie1 t4 xlvii4 p4 #bbd1
 #aheh4    ,footnote #acd3              
,traube's conceptions were governed by a
 theory of fermentation    entirely his 
own1 a hypothetical one1 as he admits1  
of which the    following is a brief    
summary3 8,we have no reason to doubt10 
,traube    says1 8that the protoplasm of
 vegetable cells is itself1 or contains 
within it1 a chemical ferment which     

causes the alcoholic fermentation    of 
sugar2 its efficacy seems closely       
connected with the presence of    the   
cell1 inasmuch as1 up to the present    
time1 we have discovered no    means of 
isolating it from the cells with        
success4 ,in the presence of    air1    
this ferment oxidizes sugar1 by bringing
 oxygen to bear upon it2    in the      
absence of air it decomposes the sugar  
by taking away oxygen    from one group 
of atoms of the molecule of sugar and   
bringing it to    act upon other atoms2 
on the one hand yielding a product of   
alcohol by    reduction1 on the other   
hand a product of carbonic acid by      
oxidation40      ,traube supposes that  
this chemical ferment exists in yeast   
and in all    sweet fruits1 but only    
when the cells are intact1 for he has   
proved    for himself that thoroughly   
crushed fruits give rise to no          
fermentation whatever in carbonic acid  
gas4 ,in this respect this    imaginary 
chemical ferment would differ entirely  

from those which we    call soluble     
ferments1 since diastase1 emulsine1 c41 
may be easily    isolated4      ,for a  
full account of the views of ,brefeld   
and ,traube1 and the    discussion which
 they carried on on the subject of the  
results of our    experiments1 our      
readers may consult the ,journal of the 
,chemical    ,society of ,berlin1 vii4  
p4 #hgb4 ,the numbers for ,september and
    ,december1 #ahgd1 in the same       
volume1 contain the replies of the two  
authors4    ,footnote #ace3      ,see   
,,pasteur1 ,comptes rendus de l',acadmie
 des ,sciences1 t4 lvi4 p4    #daf4     
,footnote #acf3      ,carbonic acid     
being considerably more soluble than    
other gases    possible under the       
circumstances4--,,ed4    ,footnote #acg3
      ,we had to avoid filling the small
 flask completely1 for fear of          
causing some of the liquid to pass on to
 the surface of the mercury in    the   
measuring tube4 ,the liquid condensed by
 boiling forms pure water1    the       

solvent affinity of which for carbonic  
acid1 at the temperature we    employ1  
is well known4    ,footnote #ach3       
,the following is a curious consequence 
of these numbers and of the    nature of
 the products of this fermentation4 ,the
 carbonic acid    liberated being quite 
pure1 especially when the liquid has    
been boiled    to expel all air from the
 flask1 and capable of perfect solution1
 it    follows that1 the volume of      
liquid being sufficient and the weight  
of    tartrate suitably chosen--we may  
set aside tartrate of lime in an        
insoluble1 crystalline powder1 along    
with phosphates at the bottom of    a   
closed vessel full of water1 and find   
soon afterwards in their place          
carbonate of lime1 and1 in the liquid1  
soluble salts of lime1 with a    mass of
 organic matter at the bottom1 without  
any liberation of gas or    appearance  
of fermentation ever taking place1      
except as far as the    vital action and
 transformation in the tartrate are     

concerned4 ,it is    easy to calculate  
that a vessel or flask of five litres   
7rather more    than a gallon7 would be 
large enough for the accomplishment of  
this    remarkable and singularly quiet 
transformation1 in the case of fifty    
grammes 7#gfg grains7 of tartrate of    
lime4    ,footnote #aci3      ,we       
treated the whole deposit with dilute   
hydrochloric acid1 which    dissolved   
the carbonate of lime1 and the insoluble
 phosphates of    calcium and magnesium2
 afterwards filtering the liquid through
 a    weighed filter paper4 ,dried at   
#ajj ,c4 7#bab ,f471 the weight of      
organic matter thus obtained was #jed   
gramme 7#hc grains71 which was    rather
 more than #a_/bjjth of the weight of   
fermentable matter4    ,footnote #adj3  
,should the solution of lactate of lime 
be turbid1 it may be clarified    by    
filtration1 after previously adding a   
small quantity of phosphate    of       
ammonia1 which throws down phosphate of 
lime4 ,it is only after this    process 

of clarification and filtration that the
 phosphates of the    formula are added4
 ,the solution soon becomes turbid1 if  
left in    contact with air1 in         
consequence of the spontaneous formation
 of    bacteria4    ,footnote #ada3     
,the naturalist ,cohn1 of ,breslau1 who 
published an excellent work on          
bacteria in #ahgb1 described1 after     
,mayer1 the composition of a liquid     
peculiarly adapted to the propagation of
 these organisms1 which it    would be  
well to compare for its utility in      
studies of this kind with    our        
solution of lactate and phosphates4 ,the
 following is ,cohn's    formula3--     
,distilled water          #bj c4c4 7#jg 
fl4 oz47                 ,phosphate of  
#ja gramme 7#ae grains74                
potassium                 ,sulphate of  
#ja gramme 7#ae grains74                
magnesium                 ,tribasic     
phosphate   #jja gramme 7#jae grain74   
of lime                 ,tartrate of    
ammonia     #jb gramme 7#c grains74     

,this liquid1 the author says1 has a    
feeble acid reaction and forms a        
perfectly clear solution4    ,footnote  
#adb3      ,on the rapid absorption of  
oxygen by bacteria1 see also our ,mmoire
    of #ahgb1 sur les ,gnrations dites  
,spontanes1 especially the note    on   
page #gh4    ,footnote #adc3      ,in   
what way are we to account for so great 
a difference between the    two         
fermentations that we have just         
described8 ,probably1 it was owing    to
 some modification effected in the      
medium by the previous life of    the   
bacteria1 or to the special character of
 the vibrios used in    impregnation4   
,or1 again1 it might have been due to   
the action of the    air1 which1 under  
the conditions of our second experiment1
 was not    absolutely eliminated1 since
 we took no precaution against its      
introduction at the moment of filling   
our flask1 and this would tend    to    
facilitate the multiplication of        
anarobian vibrios1 just as1 under       

similar conditions1 would have been the 
case if we had been dealing    with a   
fermentation by ordinary yeast4         
,footnote #add3      ,in this case the  
liquid was composed as follows3--a      
saturated solution    of lactate of     
lime1 at a temperature of #be ,c4 7#gg  
,f47 was prepared1    containing for    
every #ajj c4c4 7#c- fl4 oz47 #befe     
grammes 7#cid grains7    of the lactate1
 ,c#f;,h#e,o#e;,ca,o new notation1      
,c#f;,h#aj;,ca,o#f4 ,this solution was  
rendered very clear by the    addition  
of one gramme of phosphate of ammonia   
and subsequent    filtration4 ,for a    
volume of #h litres 7#ad pints7 of this 
clear1    saturated solution1 we used #a
 gramme  #aedc grains3--                
,phosphate of ammonia #b grammes4       
,phosphate of         #a grammes4       
potassium                               
,phosphate of         #a grammes4       
magnesium                               
,sulphate of ammonia  #je gramme4       
,footnote #ade3      #a millimetre      

#jjci inch3 hence the dimensions        
indicated will    be--length1 from      
#jjjjci to #jjjaag1 or even #jjjagf in42
 diameter1    from #jjjjjeh to #jjjjjgh1
 rarely #j4jjjaag in4    ,footnote #adf3
      ,the carbonaceous supply1 as we   
remarked1 had failed them1 and to this  
failure the absence of vital action1    
nutrition1 and multiplication was       
attributable4 ,the liquid1 however1     
contained butyrate of lime1 a salt      
possessing properties similar to those  
of the lactate4 ,why could not    this  
salt equally well support the life of   
the vibrios8 ,the    explanation of the 
difficulty seems to us to lie simply in 
the fact    that lactic acid produces   
heat by its decomposition1 whilst       
butyric    acid does not1 and the       
vibrios seem to require heat daring the 
chemical process of their nutrition4    
,footnote #adg3      ,to do this1 it is 
sufficient first to fill the curved ends
 of the    stop-cocked tubes of the     
flasks1 as well as the india-rubber tube

 c    c1 which connects them1 with      
boiling water that contains no air4     
,footnote #adh3      ,we find this fact1
 which we published as long ago as      
#ahfc1 confirmed    in a work of ,h4    
,hoffmann's published in #ahfi1 under   
the title ,mmoire    sur les bactries1  
which has appeared in ,french 7,annales 
des    ,sciences naturelles1 #eth       
series1 vol4 xi474 ,on this subject we  
may    cite an observation that has not 
yet been published4 ,arobian bacteria   
lose all power of movement when suddenly
 plunged into carbonic acid    gas2 they
 recover it1 however1 as if they had    
only been suffering from    ansthesia1  
as soon as they are brought into the air
 again4    ,footnote #adi3      ,these  
doubts might easily be removed by       
putting the matter to the test    of    
direct experiment4    ,footnote #aej3   
,,robin1 ,sur la nature des             
fermentations1 c4 7,journal de          
l',anatomie    et de la ,physiologie1   
,july and ,august1 #ahge1 p4 #chf74     

,footnote #aea3      ,,liebig1 ,sur la  
fermentation et la source de la force   
musculaire    7,annales de ,chimie et de
 ,physique1 #dth series1 t4 xxiii4 p4   
#e1    #ahgj47    ,footnote #aeb3       
,it is important that we should here    
remark that1 in the fermentation    of  
pure solution of sugar by means of      
yeast1 the oxygen originally            
dissolved in the water1 as well as that 
appropriated by the globules    of yeast
 in their contact with air1 has a       
considerable effect on the    activity  
of fermentation4 ,as a matter of fact1  
if we pass a strong    current of       
carbonic acid through the sugared water 
and the water in    which the yeast has 
been treated1 the fermentation will be  
rendered    extremely sluggish1 and the 
few new cells of yeast which form will  
assume strange and abnormal aspects4    
,indeed this might have been            
expected1 for we have seen that yeast1  
when somewhat old1 is incapable    of   
development or of causing fermentation1 

even in a fermentable    medium         
containing all the nutritive principles 
of yeast1 if the liquid    has been     
deprived of air2 much more should we    
expect this to be the    case in pure   
sugared water1 likewise deprived of air4
    ,footnote #aec3      ,,doebereiner1 
,journal de ,chimie de ,schweigger1 vol4
 xii4 p4 #abi1 and    ,journal de       
,pharmacie1 vol4 i4 p4 #cdb4            
,,mitscherlich1 ,monatsberichte d4 ,kn4 
,preuss4 ,akad4 d4 ,wissen4 zu          
,berlin1 and ,rapports annuels de       
,berzelius1 ,paris1 #ahdc1 #crd year4   
,on the occasion of a communication on  
the inversion of cane sugar1 by    ,h4  
,rose1 published in #ahdj1 ,m4          
,mitscherlich observed3 8,the inversion 
of cane sugar in alcoholic fermentation 
is not due to the globules of    yeast1 
but to a soluble matter in the water    
with which they mix4 ,the    liquid     
obtained by straining off the ferment on
 a filter paper1    possesses the       
property of converting cane sugar into  

uncrystallizable    sugar40             
,,berthelot1 ,comptes rendus de         
l',acadmie4 ,meeting of ,may #bhth1     
#ahfj4    ,m4 ,berthelot confirms the   
preceding experiment of ,mitscherlich1  
and    proves1 moreover1 that the       
soluble matter of which that author     
speaks    may be precipitated with      
alcohol without losing its invertive    
power4      ,m4 ,bchamp has applied     
,mitscherlich's observation1 concerning 
the    soluble fermentative part of     
yeast1 to fungoid growths1 and has made 
the interesting discovery that fungoid  
growths1 like yeast1 yield to    water a
 substance that inverts sugar4 ,when the
 production of fungoid    growths is    
prevented by means of an antiseptic the 
inversion of sugar    does not take     
place4      ,we may here say a few words
 respecting ,m4 ,bchamp's claim to      
priority    of discovery4 ,it is a      
well-known fact that we were the first  
to    demonstrate that living ferments  
might be completely developed1 if       

their germs were placed in pure water1  
together with sugar1 ammonia1    and    
phosphates4 ,relying on this established
 fact1 that moulds are    capable of    
development in sweetened water1 in      
which1 according to ,m4    ,bchamp1 they
 invert the sugar1 our author asserts   
that he has proved    that1 8living     
organized ferments may originate in     
media which contain    no albuminous    
substances40 7,see ,comptes rendus1 vol4
 lxxv4 p4 #aeai47    ,to be logical1 ,m4
 ,bchamp might say that he has proved   
that certain    moulds originate in pure
 sweetened water1 without nitrogen or   
phosphates or other mineral elements1   
for such a deduction might very    well 
be drawn from his work1 in which we do  
not find the least    expression of     
astonishment at the possibility of      
moulds developing in    pure water1     
containing nothing but sugar without    
other mineral or    organic principles4 
,m4 ,bchamp's first ,note on the        
inversion of sugar was published in     

#ahee4 ,in it we find nothing relating  
to the influence of moulds4 ,his        
second1 in which that influence is      
noticed1 was published in ,january1     
#aheh1 that is1 subsequently to our work
 on lactic fermentation1 which          
appeared in ,november1 #aheg4 ,in that  
work we established1 for the first      
time1 that the lactic ferment is a      
living organized being1 that            
albuminous substances have no share in  
the production of fermentation1    and  
that they only serve as the food of the 
ferment4 ,m4 ,bchamp's ,note    was even
 subsequent to our first work on        
alcoholic fermentation1 which           
appeared on ,december #bast1 #aheg4 ,it 
is since the appearance of these    two 
works of ours that the preponderating   
influence of the life of    microscopic 
organisms1 in the phenomena of          
fermentation1 has been    better        
understood4 ,immediately after their    
appearance ,m4 ,bchamp1 who1    from    
#ahee1 had made no observation on the   

action of fungoid growths on    sugar1  
although he had remarked their presence1
 modified his former    conclusions4    
7,comptes rendus1 ,january #dth1 #aheh47
    ,footnote #aed3      8,there are two
 classes of ferments2 the first1 of     
which the yeast of    beer may be taken 
as the type1 perpetuate and renew       
themselves if they    can find in the   
liquid in which they produce            
fermentation food enough    for their   
wants2 the second1 of which diastase is 
the type1 always    sacrifice themselves
 in the exercise of their activity40    
7,,dumas1    ,comptes rendus de         
l',acadmie1 t4 lxxv4 p4 #bgg1 #ahgb47   
,footnote #aee3      ,,fremy1 ,comptes  
rendus de l',acadmie1 vol4 lviii4 p4    
#ajfe1 #ahfd4    ,footnote #aef3        
,see our ,memoir of #ahfj 7,annales de  
,chimie et de ,physique1 vol4    lviii47
 p4 #fa1 and following1 and especially  
pp4 #fi and #gj1 where the    details of
 the experiment will be found4          
,footnote #aeg3      ,,pasteur1 ,comptes

 rendus de l',acadmie des ,sciences1    
vol4 lxxiii4 p4    #adai1 #ahga4        
,footnote #aeh3      ,in his ,memoir of 
#ahgj1 ,liebig has made a remarkable    
admission3 8,my    late friend          
,pelouze10 he says1 8had communicated to
 me1 nine years    ago1 certain results 
of ,m4 ,pasteur's researches on         
fermentation4 ,i    told him that1 just 
then1 ,i was not disposed to alter my   
opinion on    the cause of fermentation1
 and that if it were possible by means  
of    ammonia to produce or multiply the
 yeast in fermenting liquors1           
industry would soon avail itself of the 
fact1 and that ,i would wait to    see  
if it did so2 up to the present time1   
however1 there has not been    the least
 change in the manufacture of yeast40   
,we do not know what ,m4    ,pelouze's  
reply was2 but it is not difficult to   
conceive so sagacious    an observer    
remarking to his illustrious friend1    
that the possibility    of deriving     
pecuniary advantage from the wide       

application of a new    scientific fact 
had never been regarded as the criterion
 of the    exactness of that fact4 ,we  
could prove1 moreover1 by the undoubted 
testimony of very distinguished         
practical men1 notably by that of ,m4   
,pezeyre1 director of distilleries1 that
 upon this point also ,liebig    was    
mistaken4    ,footnote #aei3            
,,pasteur1 ,comptes rendus de           
l',acadmie1 vol4 lxxviii4 pp4 #bac-baf4 
,footnote #afj3      ,,tr,,cul1 ,comptes
 rendus de l',acadmie1 vol4 lxxviii4 pp4
 #bag1 #bah4    ,footnote #afa3         
,see on this subject the verbal         
observations which we addressed to the  
,academy of ,sciences1 at its meetings  
of ,april #ajth and #bdth1 #ahgf4       
,,chapter ,,vii4                  ,new  
,process for the ,manufacture of ,beer4 
,the principles established in the      
course of this work implicitly involve  
the conditions of a new process of      
manufacture1 the essential feature of   
which would consist in the production of

 a beer of excellent keeping  qualities1
 we might even say a beer that could not
 undergo alteration4  ,it will not be   
difficult now to make ourselves clear on
 the point4    ,we have shown in the    
first place1 that the changes which take
 place in  the ferment1 the wort1 and   
the beer itself1 are due to the presence
 of  microscopic organisms of an        
entirely different character to that of 
the  ferment-cells properly so called1  
which organisms1 by simultaneously      
giving rise1 in the course of their     
multiplication in the wort1 ferment1  or
 beer1 to other products1 make the      
materials difficult to keep or  effect  
their deterioration4 ,again1 we have    
seen that these  change-producing       
organisms1 the ferments of disease1     
never arise  spontaneously in the wort  
or beer1 but1 whenever they make their  
appearance in these fluids1 have been   
imported from without1 either in        
company with the yeast1 or from         
accession of atmospheric dust1 or from  

contact with the vessels1 or from the   
materials themselves which the  brewer  
uses in his manufacture4 ,moreover1 we  
know that these  disease-ferments1 or   
their germs1 are destroyed when the wort
 has its  temperature raised to the     
boiling-point4 ,and1 following up the   
inferences from such facts1 we have seen
 that wort exposed to pure air1  after  
having been heated to boiling1 remains  
absolutely free of any sort  of         
fermentation4    ,inasmuch then as the  
disease-germs of wort and beer are      
destroyed in the  copper in which the   
wort is boiled1 and as1 by employing a  
perfectly  pure ferment1 we guard       
against the admission of any foreign    
ferment of  an evil character1 we have  
it in our power to prepare a beer which 
shall  be incapable of undergoing any   
pernicious fermentation whatsoever4     
,this  we shall have effected provided  
we can take the wort as run off from the
  coppers1 cool and manipulate it out of
 contact with ordinary air or in        

contact with pure air1 charge it with a 
pure yeast1 and1 lastly1 store  the beer
 when the fermentation is complete in   
vessels thoroughly  purified from       
disease-ferments4#afb                   
,i4--,preliminary ,experiments4      ,we
 may readily satisfy ourselves as to the
 truth of these inferences4  ,the       
following is one of the earliest        
experiments which ,i devised with a     
view to establish their certainty4 ,into
 a flask with a straight neck of  about 
a litre 7#a-c_/d pints7 capacity1 a     
quantity of wort from a brewery  was    
introduced and there raised to boiling1 
and whilst the vapour still  issued from
 the neck of the flask1 connection was  
made with a two-necked  flask in which  
the cultivation of pure yeast had been  
carried on4 ,the  cork and glass tube   
used for this purpose had previously    
been treated  with boiling water4       
,illustration3 ,fig4 #ge4    ,when the  
wort had cooled down in the flask and   
matters were arranged as  represented in

 ,fig4 #ge1 ,i raised the two-necked    
flask so as to cause a  little of the   
liquid and yeast to flow into the wort4 
,thereupon  fermentation was set up1 and
 the resulting carbonic acid gas made   
its  escape by the drawn-out end of the 
doubled-necked flask4 ,the entire       
arrangement with its supporting stand   
remained in this connection for         
eighteen months1 sometimes on a stove1  
sometimes in the laboratory1  exposed to
 all the variations of external         
temperature4 ,at the end of  that time  
,i tasted the beer in the flask2 it was 
perfectly sound1 and  the ferment1      
submitted to the microscope1 showed not 
the slightest trace  of any foreign     
ferments3 and1 doubtless1 the experiment
 might have been  protracted over any   
number of years with the same result4   
,the only change that occurs in course  
of time is the appearance in the  neck  
of the flask at the surface of the beer 
of a deposit of small  prominences      
resembling a crystallization1 but which 

really consists of  those forms of      
ferment to which in ,chapter ,v4 ,i     
attached the name of  arobian ferment4  
,the beer1 after being transferred to a 
bottle that  had been washed with hot   
water1 was kept for several months in   
the heat  of summer1 without exhibiting 
the slightest trace of deterioration4   
,illustration3 ,fig4 #gf4               
,illustration3 ,fig4 #gg4    ,the       
essential conditions of the preceding   
experiment can readily be  realized on  
the large scale4 ,for this purpose we   
may employ the  apparatus in the above  
sketch 7,figs4 #gf and #gg7 constructed 
of tin or  tinned copper4 ,as appears   
from the sketch1 this consists of a     
cylindrical tub resting on a support1   
and closed at the top by a cover1  whose
 lower edge fits into a gutter          
containing water4 ,the wort prepared  in
 the copper is led into the cylinder1 a 
process which does not  materially lower
 its temperature4 ,now we know that wort
 in breweries  which has been cooled in 

contact with the air1 and so got charged
 with  disease-germs1 will1             
nevertheless1 recover its faculty of    
keeping for  any length of time in pure 
air1 if we again raise its temperature  
to #hj  ,c4 7#agf ,f47 or even #gj or   
#ge ,c4 7#aeh1 #afg ,f47 ,having filled 
the tub  with the hot wort and put on   
the lid1 we then connect1 by means of a 
caoutchouc tube c d1 the metal tube a c 
7which opens into one of the  tubulures 
projecting above the lid7 with the      
system of tubes d e1 f  g1 of which d e 
is fixed to the cylinder2 e f is a      
caoutchouc  junction connecting e with  
the bent glass tube g4 ,we then dash    
over  the apparatus1 lid1 tubulures1 and
 their corks a quantity of boiling      
water4 ,this collects in the gutter in  
which the lid rests1 and any  excess    
overflows into a second gutter outside  
the first1 where1 however1  it cannot   
remain1 but passes away by means of a   
ring of small holes  between the base of
 the outer trough i i and the cylinder4 

,the  overflow is collected in a third  
trough at the bottom1 whence it can be  
removed by a pipe ,m4 ,t is a bent      
thermometer to indicate the temperature 
of the wort2 its bulb is protected by an
 inlet socket d d1 pierced  with holes2 
r is a stopcock for discharging the     
water in the gutter1  which serves as a 
hydraulic junction between the cylinder 
and its lid2  ,r1 ,v1 are stopcocks1 or 
openings for the discharge of the liquid
 in the  cylinder and its deposit4 ,the 
next process is to cool the vessel1     
which  may be done either by leaving it 
to itself1 or by introducing a current  
of cold water through the tubulure ,e1  
soldered on to the lid4 ,this  tubulure 
is of the form of an inverted funnel1   
and is pierced at the  bottom with a    
close row of holes1 through which the   
cold water issues in  a sheet over the  
surface of the cover4 ,in whichever way 
the cooling is  effected1 the external  
air continues all the time to enter the 
vessel  beneath the lid by way of the   

long1 narrow passage g f e d c a1 and   
must necessarily get purified by        
depositing in its course all            
fungoid-germs1 just as happened in the  
case of the two-necked flask of  air    
experiments4 ,this1 however1 may be     
still further secured by  introducing a 
small plug of cotton wool1 or asbestos1 
into the end of  the tube g4    ,the    
experiments which we have carried out   
with this apparatus have  proved that1  
by adopting such an arrangement1 beer1 a
 liquid peculiarly  liable to change1   
may be kept as long as we wish1 for     
weeks or months1  in contact with air1  
since the tube g is open1 without       
evincing the  least symptom of disease4 
,it matters little whether the leaves   
and  strobiles of the hops are          
introduced with the hot wort or strained
 off2  the result is the same4 ,on the  
other hand1 a leak in the apparatus from
  which the wort gets mixed with        
ordinary water from outside during      
cooling1 will speedily effect a change  

in the wort and cause it to swarm  with 
vibrios1 or butyric ferment1 lactic     
ferment1 and other germs of  disease1   
whilst its taste will be rendered       
extremely nauseous4 ,it can  only be    
through one's own fault1 that is1 from  
want of skill in carrying  out the      
operation1 that any change can be       
brought about by the water in  the      
gutter not being kept out of the        
fermenting vessel4 ,that water may  even
 become putrid without the organisms    
contained in it being able to  reach the
 wort in the fermenting vessel4 ,the    
apparatus may be of any  size whatever2 
we have worked with vessels containing  
#ab hectolitres  with as much ease and  
certainty as when we used an apparatus  
of #a  hectolitre 7#bb gallons74    ,it 
is easy to carry out the process of     
cooling in the presence of  carbonic    
acid gas if we fit a bent tube1 similar 
to a c d e f g1 to  the second tubulure 
,d4 ,through this tube1 or its          
companion1 the gas can  be passed as it 

issues from an apparatus in which it is 
generated1 or  from a gasometer filled  
with it1 or from a vessel of beer       
undergoing  fermentation4    ,however1  
there is no necessity that the cooling  
should take place in the  fermenting    
vessel4 ,it may be effected separately1 
in vessels of greater  or less depth1 in
 spiral coils surrounded with cold      
water1 or in any  kind of refrigerator1 
provided always that the conditions of  
purity are  satisfied1 and that the flow
 of the cooled wort takes place under   
the  same conditions4 ,jets of steam1   
which are already extensively used for  
the cleansing of pipes in breweries1 may
 be employed here with great  advantage4
    ,the pitching may be effected in    
various ways4 ,a two-necked flask of a  
capacity of from #bjj to #cjj cc4 7about
 #g to #aj fl4 ozs471 in which not  more
 than #ajj cc4 7#c- fl4 ozs47 of wort   
has been fermented1 will be  sufficient 
for an apparatus of #a hectolitre 7#bb  
gallons71 although the  flask may not   

contain more than #a or #b decigrammes  
7#a- to #c grains7 of  yeast4 ,in the   
manufacture of beer1 as at present      
conducted1 the  employment of so minute 
a quantity of yeast would lead to most  
disastrous results4 ,the fermentation   
would unfailingly become lactic and     
butyric1 since the foreign germs with   
which commercial worts and yeasts  are  
always contaminated would have ample    
time to develop during the  first       
twenty-four or forty-eight hours1 whilst
 the small quantity of  yeast used in   
the pitching could scarcely do more than
 begin to develop  during that time4 ,it
 is simply with the object of avoiding  
these  secondary fermentations that the 
brewer uses large quantities of yeast   
for pitching4    ,after the wort and    
yeast have been pulled up1#afc a process
 which  every practical brewer adopts   
after pitching1 every part of the liquid
  is occupied by a multitude of         
yeast-cells1 which seize upon the oxygen
  in solution1 germinate with activity1 

turn to their own account the           
food-supplies most easily assimilated1  
and prevent the growth of the  germs of 
disease-ferments4 ,in the new process   
which we are now  explaining1 things    
happen quite differently4 ,our wort is  
pure1 and our  yeast is pure1 and if    
only a single cell of yeast were        
introduced into  the wort1 the vital    
activity of this would be sufficient to 
bring about  alcoholic fermentation1 and
 to transform the wort into beer1       
without our  having the least reason to 
apprehend the simultaneous development  
of any  other organisms whatsoever4 ,in 
short1 the new process enables us to    
pitch with as small a quantity of yeast 
as we like4 ,it is1 nevertheless1       
inexpedient to employ too minute a      
quantity1 since by doing so we should   
retard the commencement of fermentation4
    ,illustration3 ,fig4 #gh4           
,illustration3 ,fig4 #gi4    ,in the    
case of an apparatus of #e hectolitres  
7#aaj gallons7 or double  that capacity1

 the pitching may be accomplished by    
means of flasks  holding from #d to #i  
litres 7from #g to #aj or #aa pints71   
7,fig4 #gi71 or  copper cans1 tinned    
inside1 holding from #aj to #ae litres  
7#b-a_/d to #c-a_/d  gallons71 and      
provided at the upper conical end with  
glass tubes 7,fig4  #gh74 ,the vessel   
must be half or two-thirds filled with  
wort4 ,for this  purpose it will be well
 always to employ wort that has been    
preserved in  bottles by ,appert's      
process4 ,we must use a stopper provided
 with tubes1  as represented in ,fig4   
#gi3 a b is a glass stopper which closes
 the  india-rubber tube b c2 m n p is a 
fine glass tube1 or1 better still1  made
 of copper4    ,the tap ,r being closed1
 a long india-rubber tube is attached to
 the  extremity of the curved tube1 and 
the flask is completely immersed in a   
hot-water bath2 the india-rubber tube   
projects from the bath and keeps  the   
interior of the vessel in communication 
with the external  atmosphere4 ,if the  

tube m n p is of copper1 we may avail   
ourselves of  its flexibility and bend  
it upwards1 so as to place its open     
extremity  outside the bath4 ,the water 
in the bath is then gradually raised to 
a  temperature of #ajj ,c4 7#bab ,f471  
at which it is kept for a quarter or    
half an hour4 ,in the case of copper    
cans1 it is more convenient to place    
them over a gas-heater4 ,they may be    
treated in the same manner as the       
flasks with curved necks4 ,vessels      
prepared in this manner may remain in  a
 laboratory1 or in any part of a        
brewery1 for an indefinite time1        
without the wort in them undergoing the 
least change4 ,it gradually  darkens in 
colour through a direct oxidation of a  
purely chemical  nature1 but no tendency
 to disease will manifest itself4       
,some days before we require to pitch an
 apparatus of several  hectolitres1 we  
impregnate one of these flasks or       
cans4#afd ,for this  purpose we pass the
 flame of a spirit lamp over the tubes c

 b a and m  n p1 to destroy the         
particles of dust that might pass inside
 at the  moment when the stopper a b is 
taken out1 and then by means of a long1 
straight glass tube we take some of the 
liquid from a flask or vessel           
containing pure beer in a state of      
fermentation1 and let a few drops of    
this1 with the yeast that it holds in   
suspension1 fall into the flask or  can2
 the stopper a b is once more passed    
through the flame and then  replaced2   
generally in the course of one or two   
days the yeast develops  in the flask   
sufficiently for the fermentation to    
show itself4 ,we may  shorten the       
operation still further by emptying into
 the can the  contents of one of those  
double-necked flasks4 ,to do this1 we   
have  simply to attach the straight tube
 of the flask to the india-rubber b  c1 
and pour the liquid in4 ,in a similar   
manner we introduce1 through  one of the
 tubulures surmounting the lid of the   
fermenting apparatus1  the contents of  

the flasks or cans1 either whilst they  
are still in  active fermentation1 or   
after fermentation is over4 ,for this   
purpose1  the tap ,r is connected by    
means of an india-rubber tube 7,fig4    
#gi71 with  a tube passing through a    
cork fixed in one of the tubulures of   
the large  apparatus4 ,all this may be  
done in considerably less time than we  
have  taken to describe it2 and the     
operation may be performed accurately   
and  safely by any one who has witnessed
 it a few times1 even though he may  not
 be skilled in chemical manipulations1  
especially if he takes care to  bear in 
mind the very simple principles which we
 have explained4    ,since certain parts
 of the apparatus--the outer opening of 
the tap1 or  the india-rubber tubing1   
for example--may contract particles of  
dust from  the air1 those parts1 before 
being used1 must be boiled in water1 or 
washed with boiling water1 or passed    
through the flame of a spirit lamp1  to 
destroy the germs mixed with the        

particles of dust that settle upon      
them4    ,the method of cooling the wort
 in contact with carbonic acid prevents 
access of oxygen to the latter up to the
 time of pitching1 so that the          
development of the yeast takes place    
apart from the influence of oxygen4     
,now1 we know that these conditions     
necessitate the employment of a very    
young yeast--a yeast that is in course  
of active germination1 such as may  be  
taken from an incipient preparatory     
fermentation4 ,nevertheless1 even  with 
this1 the development of the yeast under
 such conditions is  extremely slow1 and
 the fermentation takes from fifteen to 
twenty-five  days2 whilst1 under the    
same circumstances1 but with an aerated 
wort1 it  would be finished in from     
eight to twelve days4 ,this is a        
considerable  drawback1 but1 perhaps1 a 
still more serious inconvenience is that
 the  beer takes much longer to clarify1
 and does so with greater difficulty    
than those beers which are made with    

aerated worts4 ,at the same time1  this 
is largely compensated by the superior  
quality of the beer1 which  is stronger 
and has greater fulness on the palate1  
whilst the aroma of  the hops is        
preserved to an extent never found in   
beers brewed by the  ordinary process4  
,besides this1 the yeast deposited at   
the bottom of the  fermenting vessel is 
much less active1 and1 being of an older
 type1 is  revived with greater         
difficulty than that which forms in     
aerated worts4  ,this1 which might be   
considered a disadvantage1 if we had to 
employ the  yeast afterwards for        
pitching1 has the great advantage of    
giving a beer  which1 when racked1      
undergoes its secondary fermentation    
only slowly1  and with difficulty4#afe  
,a beer of this kind is better adapted  
than  ordinary beer to stand a long     
journey without developing great        
pressure  inside the casks1 and1 if     
bottled1 it will contain very little    
deposit1  and will not froth violently  

when uncorked4 ,the reason is1 that a   
yeast  is the more active1 the more     
ready to multiply rapidly1 and to work  
vigorously the more highly aerated the  
wort was in which it was grown4  ,on the
 other hand1 a yeast formed apart from  
air readily gets exhausted1  and may    
even perish in the liquid in which it   
ferments1 when that is  kept out of     
contact with air2 in other words1 the   
vital action of yeast  is more          
restricted when it has not been         
subjected to the action of  oxygen      
during its formation4    ,if a great    
depth of wort1 the surface of which     
alone is in contact with  atmospheric   
air1 is left to cool down1 it will act  
in almost exactly the  same manner as   
that which is cooled under an atmosphere
 of carbonic acid  gas1 because the     
oxygen of the air is very slow in       
pervading wort that  is undisturbed4    
,the gas will be taken into solution by 
the upper layer  only1 whilst the bulk  
of the liquid will remain unaffected by 

it4 ,in  some experiments which we      
conducted in a vessel which contained   
wort to  a depth of #gj centimetres     
7#bge inches71 and which was provided   
with a  tap that enabled us to draw off 
some of the liquid every day1 until we  
had reduced the depth to #ce            
centimetres1 we found1 at the end of    
eight  days1 that there was not a trace 
of oxygen in solution at the latter     
depth4 ,it is even probable that1       
considering the slow diffusion of the   
oxygen1 on the one hand1 and the        
combination that may take place between 
it and certain components of the malt1  
on the other hand1 it would take  a long
 time for all the wort1 if undisturbed  
and of a certain depth1 to  become      
saturated with oxygen4 ,in the vessel   
represented in ,figs4 #gf and  #gg there
 is a considerable depth of wort to cool
 down4 ,nevertheless1 the  mere fact of 
the possibility of an aeration from the 
surface1 whilst the  wort is cooling    
down in contact with pure air1 is enough

 to account for  a certain effect that  
is produced on the yeast1 later on1 for 
the more  youthful appearance of the    
yeast of the deposit1 compared with that
  which we find in the case of wort     
cooled in the presence of carbonic  acid
 gas4 ,the difference between the       
results is particularly striking  if1 in
 both cases1 we follow up               
microscopically the development of the  
yeast during the first few days         
succeeding the pitching4    ,the        
influence of the air on fermentation is 
considerable4 ,in the  ordinary process 
of brewing1 fermentations would be      
almost impossible1  and in every case   
most defective1 if the wort1 before     
being run into the  fermenting vessels1 
were not aerated by its passage over the
 8coolers10  where the aeration is more 
or less effective1 according as the     
liquid is  more or less shallow4 ,worts 
and yeasts being impure1 that is        
containing  the germs of foreign        
ferments1 those germs would have time to

 germinate  in the fermenting vessels   
during the delay that the want of       
aeration in  the wort would cause in the
 development of the yeast4 ,we are aware
 that  several inventions have been     
proposed to do away with the coolers1   
and  we feel convinced that the object  
has been to remedy irregularities in    
fermentation4 ,considering the facts    
which we have published#aff on the      
development of yeast in the presence of 
air1 and its inactivity in  non-aerated 
media1 such inventions ought to be      
supplemented by some  means of further  
aeration for the prevention of the      
mischief that they  must otherwise      
cause4 ,in the existing process of      
brewing1 the employment  of coolers is a
 necessity4    ,the influence of the air
 on the vital action of the yeast may be
 proved  in ways innumerable4 ,the      
following is an experiment which we have
 often  carried out with surprising     
results4 ,a fermentation is going on2 we
 draw  off the liquid as rapidly as we  

please1 and pour it back again into the 
vessel immediately4 ,within an hour we  
find a marked increase in the           
fermentation1 evidenced by the          
liberation of a greater quantity of     
carbonic acid gas4 ,this experiment may 
be performed with especial ease  if we  
use the fermenting apparatus that we    
have described1 for1 by  fitting a gas  
measurer to the escape tube a b c d e f 
g1 the number of  litres produced before
 the drawing off of the liquid may be   
compared  with those obtained after4    
,the least physical change in the       
running of  the fermenting liquid whilst
 it is being drawn off1 modifies the    
effect  in question2 such as change in  
the diameter of the stream1 the height  
from which it falls1 its greater or less
 scattering in falling1 all  influence  
it4 ,again1 as might be expected from   
such results1  corresponding            
modifications take place in the cells of
 yeast which come  under the influence  
of the air4 ,they become firmer in      

aspect and  outline1 their plasma       
becomes fuller1 assumes a younger and   
more  transparent aspect1 and the       
vacuoles disappear4 ,the molecular      
granulations1 too1 are less apparent4   
,at a certain focus they disappear2  at 
another they reappear1 not as black     
spots1 however1 but as brilliant  points
 so small as to be scarcely perceptible4
 ,if germination has been  suspended it 
is resumed2 in short1 everything tends  
to prove--and having  the yeast actually
 under our eyes we cannot doubt the     
fact--that the life  of the cells is    
more decided1 and the work of nutrition 
more active  after they have been       
brought into contact with the oxygen of 
the air1  and have absorbed a greater or
 less quantity of that gas4    ,under   
the ordinary conditions of brewing1 the 
atmospheric air is present  in very     
varying quantities1 whether introduced  
by the wort which holds  more or less in
 solution1 or by diffusion over the     
surface of the  vessels1 so that the    

same cells of yeast live by turns       
without air and  with air4 ,at first    
they absorb all the oxygen held in      
solution1 and  multiply under the       
influence of this absorption4           
,afterwards1 when the  supply has been  
exhausted1 and various assimilations    
have resulted from  it1 they are        
deprived of it4 ,their life continues   
apart from oxygen1 and  if the vessel   
were closed1 fermentation would be      
accomplished under  these conditions1   
although more slowly4 ,the vessel being 
open1 a small  quantity of air diffuses 
continuously through the layer of       
carbonic acid  gas on the surface1 and  
supports the vitality of the cells4     
,it is interesting to observe that1 in  
the working of breweries1 there  are    
several empirical practices the         
explanation of which is to be found     
wholly in the fact that the aeration of 
wort or beer exercises a great          
influence on fermentation4 ,in many     
breweries we have seen the pitching     

performed in the following manner3 the  
brewer1 having mixed his yeast in  many 
times its volume of wort1 pours all the 
thick liquid from a height  from one    
bucket into another1 and from that back 
again into the first1  and so on a great
 many times1 until the two buckets are  
filled with the  froth enclosing air4   
,in certain ,london breweries we have   
seen a bucket  suspended by a pulley    
over the fermenting tun1 which is #c or 
#d metres  7#aj or #ab feet7 in depth2  
this the brewer1 by means of a cord1 can
 lower  into the tun and pull up again  
at will1 giving it a kind of see-saw    
movement which agitates the surface of  
the liquid and aerates it4 ,the  use of 
the fermenting tun itself and the       
racking of the wort from that  tun into 
casks have the effect of aerating the   
beer and the yeast1 and  imparting to   
the latter a greater vigour and         
activity4    ,the resumption of         
fermentation in cask1 after the beer has
 been run out  of the tuns in 8low0     

fermentation breweries is1 in our       
opinion1  principally due to the        
aeration of the beer at the moment when 
it is  racked4 ,the brewer ought to bear
 in mind that1 during racking1 every    
detail is of importance2 it makes a     
great difference whether when the  beer 
is run into the casks it falls from a   
height or is conducted by a  tube to the
 bottom of the casks1 whether it passes 
directly into the  casks1 or is poured  
into them from buckets1 and whether it  
runs in a  stream of small or large     
diameter1 since these different methods 
cause  the introduction of corresponding
 different quantities of air into the   
beer4    ,we have devised a simple      
arrangement for bringing the fermenting 
liquid  into contact with various       
proportions of atmospheric air4         
,appended is a  sketch of this apparatus
 7,fig4 #hj74 ,instead of one tube      
serving alike  for the entrance and     
escape of gas1 there are two similar    
ones1 each of  which opens into one of  

the tubulures on the cover4 ,round the  
other end  of one of the tubes is fitted
 a kind of muff or bag1 composed of a   
cylindrical cage of metallic gauze1 over
 which a layer of well-combed  cotton   
wool is placed1 the whole being covered 
with a muslin bag4 ,the  object of this 
arrangement is to act as an air-filter  
for retaining the  particles of dust4   
,when fermentation has commenced in the 
apparatus1 we  have simply to press     
momentarily the india-rubber connection 
between the  tube from the lid and the  
tube with the bag4 ,this will at once   
cause a  regular stream of carbonic acid
 to issue from the end of the uncovered 
tube1 whilst the air will enter by the  
filtering tube to take its place2  and  
this arrangement will be maintained     
throughout the whole course of  the     
fermentation1 even if we omit the       
precaution of increasing the power  of  
the syphon by making the tube for the   
escape of this gas longer than  the     
other one4#afg    ,illustration3 ,fig4  

#hj4    ,it will be readily understood  
how1 whether by this last method1 or by 
the diameter of the tubes1 we may vary  
the conditions of this  circulation of  
air in the apparatus1 on the surface of 
the beer4           ,,ii4--,method of   
,estimating the ,oxygen held in         
,solution in ,wort4      ,the use of    
carbonic acid gas and the cooling of the
 wort1 in contact  with that gas or in  
contact with very limited quantities of 
pure air1  are by no means necessary to 
the application of the new process4     
,there  is only one thing that is       
absolutely essential--which is1 the     
purity of  the gases in the presence of 
which the wort is cooled and treated4   
,if1  therefore1 it is well to aerate   
our wort1 either before or during       
fermentation1 this may be done1 on the  
sole condition that the air  employed   
does not introduce any germs of disease 
that are likely to  develop in the beer 
during fermentation or afterwards4 ,the 
question of  aerating the wort is not1  

however1 so simple a matter as it seems 
at  first sight4 ,a very simple         
observation will show that wort cannot  
be  safely oxygenated by exposure1      
without precaution1 to the air1 even    
leaving out of account the germs of     
disease which that air may contain4  ,it
 is easy to show that finished wort has 
a decided flavour and aroma of  hops1 as
 well as a sweet taste1 and that it     
leaves a certain pleasant1  bitter      
after-taste on the palate4 ,when we     
taste it in this condition we  cannot   
help thinking that a liquor of the kind1
 after fermentation1  ought to          
constitute a very valuable beverage1 as 
wholesome as it is  pleasant4 ,now all  
this pleasant and refreshing sensation  
that the wort  leaves on the palate1    
which is due as much to the aroma as to 
the  bitterness of the hop1 disappears  
absolutely1 we may say1 if the wort is  
left exposed to contact with air for a  
sufficient time1 and that whether  the  
air be warm or cold4 ,we may easily     

perform the experiment in one of  our   
two-necked flasks1 in which we can      
preserve the wort1 in contact  with pure
 air1 without any fear of change4 ,the  
oxygen of the air enters  into          
combination with the substances that the
 hop introduces into the  wort1 and the 
wort1 in consequence of this oxidation1 
gradually becomes  transformed into a   
saccharine decoction1 without odour1 in 
which even  the bitter flavour is       
destroyed or hidden4 ,in other words1   
the wort  grows weak and flat1 in just  
the same way that beer and wine do1 as  
well  as all the various natural or     
artificial worts which serve to produce 
them4 ,thus it is evident that          
considerable care is necessary in       
subjecting wort and beer1 whether in    
course of manufacture or finished1  to  
the action of atmospheric air4 ,if1     
therefore1 it is a good thing to  supply
 wort with oxygen1 as we have already   
pointed out1 in order to  facilitate the
 fermentation and nourish the yeast1 it 

is1 on the other  hand1 important that  
the quantity supplied to it should not  
be too  great1 otherwise we may injure  
the quality of the beer1 and            
particularly  its fulness on the palate1
 that is its apparent strength1 which   
has very  little to do with the         
proportion of alcohol in it4 ,the       
strength of a  beer is intimately       
connected with those substances         
introduced by the  hops into the wort   
and thus into the beer1 to which we     
previously  alluded1 and of which too   
little is known2 their properties and   
the  palatableness resulting from them  
are very readily affected by the  oxygen
 of the air4#afh    ,we have1 therefore1
 to ascertain the measure in which air  
occurs during  the process of brewing1  
and whether1 in the actual process1     
there may  not be too great a proportion
 of active oxygen present4 ,the study of
  this subject requires that we should  
know what quantities of oxygen may  be  
held in solution in the wort or absorbed

 by direct combination4  ,fortunately   
this has been rendered a comparatively  
easy matter by a  rapid method of       
estimating the oxygen held in solution  
in liquids of  various kinds1 devised by
 ,m4 ,schtzenberger in #ahgb4 ,as soon  
as this  method was made known1 we      
requested ,m4 ,raulin1 who was attached 
to our  laboratory as                   
assistant-director1 to apply it to the  
determination of  oxygen in wort4 ,this 
he did with his accustomed skill1       
devising certain  alterations of details
 which rendered the method at the same  
time surer  and more expeditious4       
,the principal feature in ,m4           
,schtzenberger's process consists in the
  employment of a salt1 the properties  
of which that chemist was the first  to 
recognize2 he has named it hydrosulphite
 of soda1 and it is  obtained by the    
action of zinc filings on a solution of 
bisulphite of  soda1 out of contact with
 air4    ,hydrosulphite of soda         
,s#b,o#b1,na,o1,,ho1 which is isomeric  

with hyposulphite  of soda1 only differs
 from the bisulphite by two equivalents 
of  oxygen4#afi ,when brought into      
contact with free oxygen1 it absorbs    
that  gas instantaneously and becomes   
converted into bisulphite2 similarly    
when mixed with water1 it immediately   
absorbs the oxygen held in  solution4   
,again there are colouring matters1 such
 as ,m4 ,coupier's  soluble aniline     
blue1 that are instantaneously          
decolourized by  hydrosulphite of soda1 
whilst they resist the action of the    
bisulphite4  ,if1 taking care to avoid  
the access of air1 we add hydrosulphite 
of soda  to a certain volume of water--a
 litre1 for example--that has been      
deprived  of air and faintly coloured   
with ,coupier's blue1 we shall see that 
a few  drops will be sufficient to      
effect the decoloration4 ,if1 on the    
contrary1 the water is aerated1 the     
decoloration will not be effected       
before a sufficient quantity of the     
hydrosulphite has been added to  absorb 

the oxygen in solution1 and the volume  
of the reagent required is  in          
proportion to the quantity of oxygen in 
solution in the water4 ,to  render the  
process sensitive1 we must dilute the   
hydrosulphite to such  an extent that   
#aj c4c41 for example1 may correspond   
very nearly with #a  c4c4 of oxygen4 ,if
 the reagent would keep we should only  
have to  determine directly1 once for   
all1 the volume of oxygen that a known  
volume of the liquid could absorb2 but1 
in consequence of its extreme  liability
 to change through contact with air1 it 
is necessary to titrate  the liquid     
every time before using it4 ,this is    
easily done in the  following manner3-- 
,according to the observations of       
,messrs4 ,schtzenberger and ,lalande1   
the  hydrosulphite decolourizes an      
ammoniacal solution of sulphate of      
copper1  reducing the copper to a lower 
state of oxidation2 the sulphite and    
bisulphite having no action as long as  
there is an excess of ammonia4 ,we      

prepare a strongly ammoniacal solution  
of sulphate of copper1 containing  such 
a quantity of copper that #aj c4c4 of   
the liquid will correspond1 as  far as  
action on the hydrosulphite is          
concerned1 with #a c4c4 of oxygen4      
,calculation by equivalents gives us the
 correct value verified by direct       
experiment4#agj    ,the object of the   
modification which ,m4 ,raulin has      
introduced1 is to  avoid the loss of    
time thus occasioned by the changes     
which take place  in the titrated       
liquids by long keeping1 as well as     
certain errors which  may arise from the
 acidity of the wort4 ,on this latter   
point ,m4  ,schtzenberger has remarked  
that the quantities of hydrosulphite of 
soda  corresponding with one and the    
same volume of oxygen vary with the     
acidity of the liquid operated upon1 a  
phenomenon which that skilful  chemist  
explains by the formation of oxygenated 
water1 of varying  stability in media of
 different acidity4    ,instead of      

determining the strength of the titrated
 solution of  hydrosulphite before each 
operation1 we take the solution as it   
happens  to be1 and determine its       
strength by causing it to act on a known
 volume  of pure water saturated with   
oxygen at a certain temperature4 ,the   
tables  of solubility of oxygen in water
 give the exact volume of oxygen on     
which the measured volume of            
hydrosulphite used has acted4 ,according
 to  ,bunsen1 about one minute's brisk  
shaking in a closed bottle1 with excess 
of air1 will be sufficient to effect the
 maximum saturation of the water  at the
 temperature at which we operate4       
,for experiments on wort we require3--  
#a4 ,a #b-litre 7#c- pints7 flask1 ,a1  
containing saturated hydrosulphite  of  
soda1#aga of such strength that #be c4c4
 will be sufficient to  absorb almost   
all the oxygen in #ej c4c4 of water     
saturated with air at  the ordinary     
temperature 7that is1 #a volume of      
hyposulphite must equal  #bj volumes of 

water74    #b4 ,a #b-litre flask1 ,b1   
containing a solution of indigo-carmine1
 #ej c4c4  of which will be decolourized
 by about #bj c4c4 of the hydrosulphite4
  ,this solution contains about #bj     
grammes 7#cjg grains7 of commercial     
indigo-carmine per litre 7#agf pints74  
#c4 ,an apparatus1 ,c1 for the          
production of hydrogen4    #d4 ,an      
experimental apparatus composed of a    
burette1 ,d1 graduated in  tenths of a  
cubic centimetre1 and a three-necked    
,wollf's bottle1 ,e4    #e4 ,a flask1   
,f1 holding about #ajj c4c4 provided    
with a straight tube  divided into      
tenths of a cubic centimetre1 and       
containing a solution of  ammonia of    
such strength that about ten drops of it
 will neutralize the  acidity in #ej    
c4c4 7#agf fl4 oz47 of wort4    ,to     
perform the operation we shake about    
#aej c4c4 7#ec fl4 oz47 of  distilled   
water1 at the existing temperature1 in a
 #a-litre flask for a  minute or so2    
this saturates it with air1 and we must 

at the same time  note the temperature4 
,to be extremely precise1 we should note
 also the  barometrical pressure4       
,illustration3 ,fig4 #ha4    ,into the  
bottle ,e we introduce about #ej c4c4 of
 the indigo solution1 and  #bjj c4c4 of 
water at about #fj ,c4 7#adj ,f471 and  
fill the tube e to  the point b with    
water saturated with air2 we then expel 
the air from  the bottle ,e by a current
 of hydrogen4 ,the blue colour of the   
liquid in  the bottle is then very      
carefully brought to a yellow tint1 by  
running  in1 drop by drop1 the          
hydrosulphite with which the burette ,d 
is filled4    ,we next pour #ej c4c4 of 
distilled water saturated with air into 
the  funnel a1 and pass it into the     
flask2 the blue colour reappears4 ,we   
must then bring back the colour to      
exactly the same tint of yellow4 ,let  n
 represent the number of divisions on   
the burette denoting the volume  of     
hydrosulphite employed for this purpose4
    ,we repeat this last operation      

immediately1 taking #ej c4c4 of the     
wort1  the oxygen of which we wish to   
determine1 having first introduced into 
the funnel a a sufficient number of     
drops of the ammoniacal solution  to    
neutralize the acidity of the wort4 ,let
 n represent the number of  divisions of
 hydrosulphite employed to restore the  
yellow tint in the  case of the wort4   
,we once more perform the experiment    
with #ej c4c4 of saturated water2 let  n
 be the number found4#agb    ,the ratio 
which the quantity of oxygen held in    
solution in the wort  bears to the      
quantity of oxygen contained in the same
 volume of water  saturated with air1 at
 the temperature t1 and under the       
pressure ,h1  will be    ,illustration3 
,formula #c3 n_/77n  n7_/#b74    it will
 be sufficient in most cases to bear in 
mind this ratio4    ,when we want to    
deduce the absolute quantity of oxygen  
held in solution  in a volume ,v of the 
wort1 we have merely to multiply this   
ratio by the  quantity of oxygen        

contained in the same volume of water   
saturated with  air1 at the temperature 
t and under the pressure ,h1 a very     
simple  problem if we know the          
coefficients of the solubility of oxygen
 in water  at different temperatures4   
,these coefficients are given for       
ordinary  temperatures in the following 
table1 which was compiled by ,bunsen4   
,we  have restricted the numbers to     
three places of decimals3--             
,temperatures4        ,coefficients4    
#j ,c4 7#cb ,f47       #jjdj            
#a ,c4 7#cch ,f47     #jjdj             
#b ,c4 7#cef ,f47     #jjci             
#c ,c4 7#cgd ,f47     #jjch             
#d ,c4 7#cib ,f47     #jjcg             
#e ,c4 7#daj ,f47     #j #jcf           
#f ,c4 7#dbh ,f47     #jjce             
#g ,c4 7#ddf ,f47     #jjce             
#h ,c4 7#dfd ,f47     #jjcd             
#i ,c4 7#dhb ,f47     #jjcc             
#aj ,c4 7#ejj ,f47    #jjcc             
#aa ,c4 7#eah ,f47    #jjcb             
#ab ,c4 7#ecf ,f47    #j #jca           

#ac ,c4 7#ee #d ,f47    #jjca           
#ad ,c4 7#egb ,f47    #jjcj             
#ae ,c4 7#eij ,f47    #jjcj             
#af ,c4 7#fjh ,f47    #jjbi             
#ag ,c4 7#fbd ,f47    #jjbi             
#ah ,c4 7#fdd ,f47    #jjbi             
#ai ,c4 7#ffb ,f47    #jjbh             
#bj ,c4 7#fhj ,f47    #jjbh    ,the     
primary condition which enables us to   
rely on the exactness of this  method is
 the fact which we have mentioned above1
 that a liquid if  shaken up with air   
for one minute will become perfectly    
saturated with  oxygen4 ,substantially  
this is the case4 ,in estimating the    
oxygen in  different parts of a liquid  
treated thus1 we have invariably        
obtained  the same figures to within    
about #a_/ejth4    ,it is true that the 
variable quantity of the oxygen held in 
solution in  the liquid contained in the
 part of the tube eb1 as well as the    
oxygen  absorbed during the treatment of
 the liquid in contact with air1        
constitute causes of error4 ,experience1

 however1 proves that these  causes of  
error are insignificant1 as long as we  
have to deal with a  liquid the aeration
 of which is not very far removed from  
the point of  saturation1 and whose     
solubility-coefficient for oxygen is not
 widely  different from that of water   
for the same gas4 ,under such conditions
 we  have always found a constant ratio1
 to within about #a_/djth between the   
same liquid and air-saturated distilled 
water1 placed under the same            
circumstances4    ,if1 on the other     
hand1 we have to deal with a liquid     
which holds but a  minute quantity of   
oxygen in solution1 the causes of error 
mentioned may  very seriously affect our
 results1 and it will be absolutely     
necessary  to avoid them4 ,the liquid   
experimented on must be treated out of  
contact  with air1 by aspirating it     
directly from the vessel that contains  
it  into the pipette ,h1 which is       
graduated for #ej c4c41 and causing it  
to  pass thence into the flask ,e1 by   

substituting the pipette for the funnel 
a4 ,finally1 before arranging the       
pipette1 we cause a small quantity of   
the liquid in the flask1 which has been 
previously brought to the exact  yellow 
tint1 to pass1 by pressure1 through the 
tube eb1 so as to avoid  the cause of   
error that is likely to result from the 
air held in  solution in the liquid of  
that tube4    ,the liquid1 the oxygen of
 which has to be determined1 may also be
 passed  directly from the vessel       
containing it into the flask ,e2 the    
rest of the  operation being performed  
as already described4    ,it was by this
 method that the oxygen held in saturate
 solution in wort  was determined4 ,the 
following are the principal results     
obtained by ,m4  ,raulin3--    #a4 ,at  
different pressures the ratio between   
the quantities of oxygen  held in       
solution in water and in wort is1 all   
other conditions being  similar1        
constant4 ,this ratio has been found    
equal to #abj in the case  of wort and  

water saturated with air at the ordinary
 pressure1 and #abd  in the case of wort
 and water saturated with pure oxygen4  
#b4 ,the ratio between the coefficient  
of the solubility of oxygen in  water   
and that of its solubility in wort is   
very nearly constant at  different      
temperatures1 increasing1 however1      
slightly as the temperature  diminishes4
    ,this ratio has been found to be--  
,temperatures4                     #bf  
,c4           7#ghh ,f47   #abj         
#aie ,c4         7#fga ,f47   #abe      
#d ,c4            7#cib ,f47   #acg     
,another wort gave the following        
results3--                              
,temperatures4                     #i   
,c4            7#dhb ,f47   #aae        
#ba ,c4           7#fih ,f47   #aaj     
#be ,c4           7#ggj ,f47   #ajg     
#c4 ,the ratio between the quantities of
 oxygen held in solution in water  and  
those held in solution in wort increases
 with the concentration of  the wort4   
,by evaporating the same wort to        

different degrees of  concentration1 and
 afterwards saturating it with air1 at  
the same  temperature1 we obtained the  
following figures for the ratio in      
question3--                     ,weak   
wort                      #ajf          
,the same evaporated to half    #aae    
8        0      8  #b_/e         #abg   
0        8      0  #c_/aj        #ade   
8        0      8  #a_/f         #aif   
#d4 ,worts of different origin1 but of  
the same density and temperature1  when 
saturated with oxygen1 always contain   
very nearly the same quantity  of that  
gas4    ,two portions of the same wort1 
shaken up with air1 one being hot the   
other cold1 then left to themselves for 
some time1 and afterwards  saturated    
with air1 at the same temperature1 gave 
the figures #abb for  the ratio between 
the oxygen in the water and that in the 
wort4    ,different worts of the same   
density1 saturated at a temperature of  
#ae  ,c4 7#ei ,f471 gave the following  
ratios3--                 ,wort kept in 

a bottle with air for #ai    #aadj      
months                 ,wort recently   
prepared                   #aadb        
,wort kept in a bottle without air for  
#bj #aadb               months1 aerated 
for #ah days                 ,wort      
evaporated to dryness and made up       
#aabf               with water    #e4   
,the solubility of oxygen in wort       
differs very little from the  solubility
 of oxygen in sweetened water of the    
same density4    ,an experiment was made
 with a solution of sugar on the one    
hand1 and  with wort more or less       
diluted with water on the other hand1 at
 the same  temperature of #aa ,c4 7#eah 
,f474 ,the following figures were       
obtained  for the ratios of             
solubility3--                           
,solution   ,wort4                      
of ,sugar4                   ,marking   
#agi             #abgh      #abg        
,balling#agc                   8    #adj
    0           #aaij      #aae         
8     #gj    0           #ajib      #ajf

    #f4 ,from the preceding results it  
is easy to deduce a general formula     
which shall give the coefficient of     
solubility of oxygen in any wort1       
marking ,b by ,balling1 and at          
temperature t4    ,from the figures of  
7#b7 it follows that above and below the
 temperature  of #ae ,c4 7#ei ,f471 the 
ratio which the coefficient of          
solubility of  oxygen in water bears to 
that of the solubility of the same gas  
in wort  varies about #jjjf for each    
degree of the thermometer4 ,from the    
figures  of 7#c7 it follows that the    
same ratio varies about #jjjb for each  
degree  of ,balling above and below the 
#aeth degree on the instrument4    ,by  
taking c for the coefficient of         
solubility of oxygen in water at  t ,c41
 and c for that of oxygen in wort also  
at t ,c41 and having  a density ,b1 by  
,balling at #ae ,c42 and taking ,x for  
the ratio  c_/c1 at #ae ,c4 and #ae     
,balling1 we shall have        c_/c  ,x 
7,b - #ae7 #jjbb - 7t - #ae7 #jjjf4     

,by carefully ascertaining the ratio    
c_/c for different worts1 and  adopting 
the preceding formula1 we have found for
 ,x a mean value of  #aaf4    ,the      
definitive formula1 therefore1 is3      
7#a7 c_/c  #aaf  7,b-#ae7 #jjbb - 7t -  
#ae7 #jjjf1    or again1        7#b7    
c_/c  #jhf - 7,b - #ae7 #jjaf  7t - #ae7
 #jjjd4    ,the coefficient c of the    
solubility of oxygen in water will be   
found  in the table given a few pages   
back4         ,,iii4--,on the ,quantity 
of ,oxygen existing in a state of       
,solution in                            
,brewers' ,worts4#agd      ,the wort1   
when it comes from the copper in which  
it is boiled with the  hops1 remains    
exposed upon the coolers for a time1 the
 length of which  varies according to   
circumstances1 the most important of    
which is the  exterior temperature4 ,the
 average time is from seven to eight    
hours1  during which the volume of the  
wort diminishes1 whilst its density     
increases2 at the same time1 it deposits

 its proteinaceous matters and  absorbs 
oxygen from the air1 either by way of   
solution or of  combination4    ,in the 
present paragraph we shall confine      
ourselves to the uncombined  oxygen held
 in a state of solution in wort1        
recognizable by the change  of colour   
produced by its action on white indigo4 
,the use of the coolers enables the     
brewer to obtain his wort in two        
distinct states of limpidity--filtered  
wort and unfiltered wort4 ,at the  same 
time there is a further difference      
between these worts1 namely1 in  the    
quantity of oxygen held in solution4    
,the unfiltered wort comes  direct from 
the coolers2 the wort to be filtered1   
mixed with a part of  the deposit1 is   
run into a special vessel1 from which it
 is distributed  over the filtering     
surfaces1 which are generally of felt2  
filtered  bright1 it is then received in
 a reservoir1 from which it is          
distributed  amongst special fermenting 
vessels4 ,falling through the air in a  

thin  stream of drops1 it must          
necessarily have become charged with a  
greater  quantity of oxygen than        
ordinary wort4 ,in good breweries it is 
put apart  by itself to ferment1 and the
 yeast which it yields is firmer and    
deposits more easily than that of       
unfiltered wort4 ,as for the            
fermentation1 it is1 under similar      
conditions1 quicker by a day or a day   
and a half than in the case of ordinary 
wort4 ,the difference in the  quantity  
of oxygen held in solution in the two   
kinds of wort is greater  in proportion 
as the external temperature is lower2 in
 winter it may be  twice as great as in 
summer4 ,the reason is that in summer a 
boiling wort  does not obtain a minimum 
temperature of #bj ,c4 7#fh ,f471 on the
 best  coolers1 in less than six or     
seven hours4 ,after leaving the coolers 
it  is passed over a refrigerator4 ,in  
winter it attains that temperature in   
about three hours1 or less1 which then  
goes on sinking on the coolers4  ,during

 the last two or three hours which are  
employed in bringing the  temperature   
still lower1 as also during the running 
off1 the wort  absorbs an appreciable   
quantity of oxygen4 ,in other words1    
wort in  winter remains for a longer    
time at low temperatures1 in free       
contact  with air4    ,another          
circumstance unites with this exposure  
upon the coolers to  increase the       
aeration of the wort2 the wort is run   
into the fermenting  tuns through pipes 
of large sectional area1 more or less   
bent1 and  carries with it by suction   
considerable quantities of air1 which1  
from  the continual agitation1 gets well
 mixed with it4 ,the effect of this     
mixing in the pipes is to considerably  
increase the proportion of air in       
solution in the wort1 especially in     
winter1 when the temperature of the     
wort is lower2 and from the figures     
given below we may1 although it is  very
 variable1 put the average increase at a
 quarter of the whole  amount4 ,the     

calculation has been made by comparing  
the quantities of air  held in solution 
in two samples of the same wort1 one of 
which was taken  from the coolers at the
 moment of 8turning out10#age and the   
other from  the fermenting vessel after 
it was filled4    ,let us call the ratio
 between the quantity of oxygen held in 
solution by  a wort1 and that which the 
same wort would hold in solution if     
saturated  at the same temperature1 the 
degree of saturation of that wort at the
  temperature t4    ,the determination  
of degrees of saturation is reduced to a
 comparison of  the number of divisions 
of hydrosulphite n which satisfies the  
wort in  the first case1 with the number
 n corresponding with the same wort     
saturated at the same temperature4 ,the 
ratio n_/n gives the degree  of         
saturation at the temperature t4    ,in 
experiments made with a wort at #ade    
,balling as mean density1 we  found the 
following results3--    ,in summer1 in  
the case of worts reduced to the        

temperature of #e ,c4 7#da  ,f47 by a   
refrigerator1 the degrees of saturation 
may be set down as--                    
,for unfiltered worts #jejj             
,for filtered worts   #jhjj    ,in      
winter1 in the case of some worts which 
were racked at a temperature  of from #c
 to #d ,c4 7#cgd to #cib ,f471 without  
the use of a  refrigerator1 we found the
 saturation complete in both worts4 ,in 
the  case of a very low external        
temperature1 however 7-#aj ,c41 #ad     
,f471 we  have failed to determine the  
saturation in an unfiltered wort4 ,as   
regards the mean winter figures1 in the 
case of worts racked at a  temperature  
of #e ,c4 7#da ,f471 they may be fixed  
at these3--                             
,for unfiltered wort  #jhej             
,for filtered wort    #jiej    ,in      
autumn and spring we find the mean      
figures to be intermediate between      
those given above3--                    
,for unfiltered wort  #jejj to #jhej    
,for filtered wort    #jhjj to #jiej    

,from these ratios it is easy to find   
the quantity of oxygen contained in     
brewers' worts1 if we also refer to     
,bunsen's ,tables and the formula 7#b7  
given in the preceding section4 ,at the 
temperature of #e ,c4 7#da ,f471 at     
which the above worts were              
8gathered10#agf and not taking into     
account  the very small correction that 
should be made for the difference of    
half  a degree on ,balling1 we find1 by 
this formula1 as the ratio of the       
coefficients of the solubility of oxygen
 in saturated wort and in water--       
c_/c  #jhb    ,now1 at the temperature  
of #e ,c41 the quantity of oxygen held  
in  solution in #a litre of water is1   
according to ,bunsen1 #jjcf litre1 at   
the atmospheric pressure1 and therefore 
at the pressure of #a_/eth  atmosphere1 
which is that of the oxygen in          
atmospheric air1 it will be--           
#jjcf_/e litre  #gb c4c4--that is1 #b   
cubic inches per gallon4    ,and1       
consequently1 in the case of saturated  

wort1 it will be--        #gb c4c4  #jhb
  #eijd c4c4--that is1 #afb cub4 inches 
per gall4    ,multiplying this last     
number of c4c4 by the different degrees 
of  saturation found1 we shall obtain   
the volumes of oxygen held in  solution 
in #a litre of different worts3--       
,summer worts ,unfiltered #jejj  #eijd  
c4c4  #bieb c4c4                        
,filtered   #jhjj  #eijd  8    #dgbc  0 
,winter worts ,unfiltered #jhej  #eijd  
8    #ejah  0                           
,filtered   #jiej  #eijd  8    #efji  0 
,it is important to notice that we are  
here dealing with wort taken from  the  
fermenting vessel just before it was    
pitched2 that is to say1 when  the      
quantity of oxygen held in solution was 
as large as the treatment to  which it  
had been subjected allowed of its being4
 ,the mode of taking it  for examination
 is as follows3--,a burette1 ,h 7,fig4  
#ha71 is plunged into  the fermenting   
vessel1 the temperature of which at the 
time is  ascertained very exactly1 the  

upper part of the burette being fitted  
with an india-rubber tube1 a b1 longer  
than itself4 ,the liquid is then  sucked
 up the tube1 and soon completely fills 
the apparatus and runs out  at b 7,fig4 
#hb74 ,by lowering the tube the whole   
arrangement thus forms  a syphon1 and   
enables us to let the wort that we are  
experimenting on  flow for some minutes2
 when every trace of air has been thus  
expelled1  the lower tap is closed and  
the liquid is introduced into           
,schtzenberger's apparatus4             
,illustration3 ,fig4 #hb4    ,as for the
 saturated wort1 the value of which in  
oxygen serves to  determine one of the  
elements of the degree of saturation1 it
 is readily  obtained by introducing a  
volume of from #ajj c4c4 to #aej c4c4 of
 wort  into a #b-litre or #c-litre      
flask1 and shaking it briskly so as to  
saturate it with air2 it is then poured 
into a settling-glass1 to  separate it  
from the great quantity of froth formed 
in the shaking1 and  then1 by means of a

 graduated pipette1 #ej c4c4 is taken   
for examination4    ,we have spoken of  
the influence that oxygen has on the    
activity of  yeast1 on its development  
and1 consequently1 on the progress of   
fermentation4 ,moreover1 we know1 from  
experiments already mentioned1  which we
 communicated to the ,academy and the   
,chemical ,society in #ahfa1  that the  
rapid development of yeast in contact   
with air is in reciprocal  relation to  
the disappearance of the oxygen from the
 air4 ,knowing the  conditions of the   
aeration of wort from the moment when it
 arrives on  the coolers until the      
moment when1 in the fermenting tun1 it  
is about to  be pitched1 it would be    
interesting to ascertain what happens to
 the  oxygen dissolved in the wort at   
the moment of pitching1 how yeast is    
affected when suddenly brought into     
contact with that oxygen2 what part1  in
 short1 that gas plays in fermentation4 
,let us therefore follow up1 hour by    
hour1 the degree of saturation after    

pitching1 in ,tourtel's brewery4 ,on    
,november #dth1 #ahge1 some wort at #ad 
,balling was pumped on to the coolers at
 #g p4m41 and at #d a4m4 went down  to a
 #cb-;hectolitre 7#gjj gallons7 tun1 its
 temperature then being #f ,c4  7#dbh   
,f47 ,the pitching1 in which about #ajj 
grammes 7#cb oz4 troy7 of  pressed yeast
 was used per hectolitre 7#bb gallons71 
took place at #e a4m4  ,the following is
 the curve of the degrees of saturation 
of the oxygen1  as drawn by ,messrs4    
,calmettes and ,grenet4                 
,illustration3 ,fig4 #hc4    ,the       
absciss represent the time expressed in 
hours1 and the ordinates  give the      
degrees of saturation of the wort with  
oxygen4 ,it will be seen  that about    
twelve hours after the pitching1 and at 
a temperature of #f  ,c41 all the oxygen
 had disappeared1 absorbed by the yeast4
 ,we shall find  that wort by itself1   
unassociated with yeast1 would also have
 combined  with oxygen2 but in the      
course of twelve hours1 at #f ,c41 this 

combination would have been scarcely    
appreciable in absence of yeast4 ,it    
follows1 therefore1 that the oxygen in  
solution is taken up by the  yeast1     
under the conditions of which we are    
speaking4 ,this has been  proved        
directly by an experiment4 ,a double    
quantity of yeast was  employed for a   
tun similar to the preceding one1 and it
 was found that  the oxygen in solution 
disappeared completely in less than half
 the time  that it took to disappear in 
the first case4#agg ,it is very         
important  to notice that in our        
#cb-;hectolitre tun1 at the moment when 
we  determined the complete             
disappearance of the oxygen in solution1
 the  cells of yeast had assumed a      
younger and fuller appearance than they 
had  at first2 but they had not         
multiplied at all up to that time1 nor  
were  there even any buds then visible  
on them4 ,the oxygen1 therefore1 must be
  stored up somehow in the cells1 taken 
up by their oxidizable matters to  be   

brought into work subsequently1 or to   
act as a primum movens of  life and     
nutrition1 spreading its influence over 
several successive  generations of      
cells4                    ,,iv4--,on the
 ,combination of ,oxygen with ,wort4    
,the atmospheric oxygen is not merely   
taken into solution by wort2 it  also   
combines with it1 as a very simple      
experiment will suffice to show4  ,if we
 place in a tinned iron vessel some     
boiling wort1 separated from  the hops  
in the copper1 and cool it suddenly by  
plunging it into iced  water1 and after 
having cooled it down in this manner to 
#ae or #bj ,c4  7#ei or #fh ,f471       
saturate it with oxygen1 by shaking it  
briskly in a  large flask1 and then     
completely fill a vessel with it and    
close it up  for twelve hours1 we shall 
find at the end of that time1 if we test
 it  with the hydrosulphite of soda1 as 
we have described in  ,,ii41 that it    
does not contain a trace of free oxygen4
 ,the whole of the gas which was        

originally held in solution will have   
entered into combination1 that is  to   
say1 the liquid1 first coloured blue    
with the indigo-carmine1 and  then      
brought to a yellow tint by means of the
 hydrosulphite of soda1  will not regain
 its original blue colour through the   
action of this  wort4 ,the following    
experiments were undertaken with the    
object of  studying this property of    
wort1 and in order that we might form   
some  idea of its importance1 and of the
 total quantity of oxygen that wort  can
 absorb under certain special           
circumstances4 ,the experiments were    
performed in our own laboratory on wort 
from ,tourtel's brewery1 which ,m4      
,calmettes had forwarded to us in       
bottles prepared in the brewery at      
,tantonville1 in the following manner3  
,each bottle was filled with  boiling   
wort taken from the copper and closed   
with a bored cork1 through  which the   
neck of a funnel passed2 the funnel also
 was filled with the  wort1 and the     

whole preserved from contact with air by
 a layer of oil4  ,the next day the     
bottles were corked full by the help of 
a bottling  needle1#agh previously      
heated1 with perfect corks that had been
 passed  through the flame4 ,the bottles
 arrived in ,paris in very good         
condition1  quite full of the liquid up 
to the corks4 ,they were left           
undisturbed for  one or two days at the 
same temperature as that to which they  
had been  exposed during the corking and
 the journey4 ,the object of this was to
  afford time for a deposit of the wort 
to form at the bottom of each  bottle4  
,as a matter of fact1 we know that wort 
boiling in the copper is  charged with  
proteinaceous matters and other floating
 and insoluble  substances4 ,the wort   
above the deposit was turbid and        
opaline2 it was in  this state when we  
used it for our experiments4 ,it may be 
taken for  granted1 without risk of     
appreciable error1 that the wort had    
been  absolutely deprived of oxygen in  

solution1 inasmuch as it had been       
bottled when boiling1 and had cooled    
down out of contact with air4 ,as  for  
the quantity of oxygen that it might    
have held in combination1 this  must    
have been insignificant1 although there 
must have been some1 since  the wort had
 been exposed to the air in the copper2 
the oxygen in  combination1 however1    
could have had no appreciable influence 
on the  results which we obtained4 ,let 
us call this wort boiled wort4    ,first
 ,experiment4--,into a straight-necked  
flask we introduced a certain  measured 
quantity of this wort by means of a     
syphon1 taking care that  the syphon    
should only act on the opaque wort1 and 
should not reach the  deposit at the    
bottom of the bottle4 ,we then drew out 
the neck to a fine  tube in the flame   
and boiled the wort2 and during         
ebullition we sealed  the end of the    
fine tube4 ,after it had cooled1 we     
arranged that pure air  should enter the
 flask4 ,to do this we made a file mark 

near the fine  closed point of the      
flask1 and connected the point by a     
piece of  india-rubber tubing with a    
glass tube containing a column of       
asbestos1  which we heated4 ,we then    
broke off the point of the flask inside 
the  india-rubber tube1 so that the air 
entered the flask after being  filtered 
through the asbestos4 ,we removed the   
india-rubber tube and  sealed up once   
more the fine end of the neck at the    
point where we had  broken it off4      
,finally1 to aerate the wort to         
saturation1 we shook the  flask briskly 
for some minutes1 and then placed it in 
a hot-water bath1  where we left it for 
about a quarter of an hour4 ,we         
afterwards removed  it to an oven at #be
 7#gg ,f474 ,we repeated the same       
operation next day  and the four        
succeeding days4    ,the wort1 which at 
first was scarcely coloured1 gradually  
assumed a  reddish-brown tint1 and      
deposited an amorphous matter1 but      
without  brightening4 ,it became clear1 

however1 when filtered1 which was not   
the  case with the turbid1 opaline wort 
in the bottles when they arrived4       
,the following is an analysis of the air
 in the flask1 made immediately  after a
 renewed and vigorous shaking1 the      
object of which was to  saturate the    
wort with air before analyzing the      
supernatant air3--        ,november     
#bith4              ,temperature at     
which the flask was refilled with air #d
 ,c4          7#bib ,f47                
,atmospheric pressure #gea mm4 7#bif    
ins47                      ,total volume
 of flask #ccc c4c4 7#bjcb cub4 in47    
,volume occupied by the wort #abj 8 7   
#gcb 0 7        ,december #hth4         
,volume of gas analyzed #bgf c4c4 7#afh 
cub4 ins47                      ,after  
treatment with potash #bgd c4c4 7#afg 8 
7                        0 8 pyrogallol 
#bbd 0 7#acf 8 7                        
,oxygen #ej c4c4 7#jcje cub4 in47       
,composition of the gas3-- ,per cent4   
,oxygen #ahbe            ,nitrogen #haeg

    ,the formula which we deduced above 
7 ,,ii47 allows us to conclude that at  
the temperature of #h ,c4 7#dfd ,f471   
which was the temperature at which  the 
wort was saturated before the analysis  
given above1 the quantity of  oxygen in 
solution in the #abj c4c4 7#db fl4 oz47 
of wort was #jhd c4c4  7#jjea cub4 in474
    ,at the moment when the flask was   
closed1 the total volume of oxygen1     
calculated to zero and #gfj mm4 7#cj    
in47 pressure1 was #ddgc c4c4 7#bgbi    
cub4 in474    ,at the moment when the   
analysis was finished1 the volume of    
oxygen was  calculated to the same      
conditions of temperature and pressure1 
#chhf  c4c4 7#bcee cub4 in472 #ehg c4c4 
7#jcgd cub4 in47 has1 therefore1        
disappeared4 ,now1 as there is #jhd c4c4
 7#jjea cub4 in47 in solution1  there   
has1 consequently1 been an absorption1  
by combination with #abj  c4c4 of wort1 
of #ejc c4c4 7#jcb cub4 in47 of oxygen1 
or #dag c4c4 per  litre 7#aaf cub4 ins4 
per gallon74    ,second                 

,experiment4--,in a similar experiment1 
in which1 however1 the  flask was kept  
for five days at a rigorously constant  
temperature of #ee  ,c4 7#aca ,f471 day 
and night1 and in which the supernatant 
air was not  shaken up with the wort1 we
 found--        ,volume of gas analyzed 
#bhe            ,after treatment with   
potash #bhc              8 0 8          
pyrogallol #bcj               ,oxygen   
#ec        ,composition of the gas3--   
,per cent4            ,oxygen #ahf      
,nitrogen #had        ,total oxygen at  
first #bidj          8 0 remaining #bfjd
          8 0 that has disappeared #ccf 
8 0 in solution #jed          8 0 in    
combination #bhb          ,or per litre1
 #ceb c4c4 7#ih cub4 ins4 per gallon74  
,the colour of the wort in this         
experiment had become sensibly similar  
to  that of the wort in the preceding   
experiment4    ,third ,experiment4--,in 
another experiment we left the flask1   
for the  same length of time again1     
after it had been refilled with air and 

reclosed1 at a temperature which varied 
between #b and #d;,c4 7#cef and  #cib   
,f474 ,in this case we found--          
,volume of air analyzed #bgh            
,after the action of potash #bgh        
,after pyrogallic acid #bbc             
,oxygen #ee          ,composition of the
 gas3-- ,per cent4              ,oxygen 
#aig              ,nitrogen #hjc        
,total oxygen at first #bidj c4c4       
8 0 remaining #bgeh                8 0  
that has disappeared #ahb               
8 0 in solution #jdd                8 0 
in combination #ach                ,or  
per litre1 #agbj c4c4 7#dh cub4 ins4 per
 gallon74    ,in this last experiment   
the wort was scarcely darker in colour4 
,its  colour1 compared with that of wort
 cooled on the coolers in the brewery1  
was slightly darker2 but the difference1
 although it existed1 was  scarcely     
appreciable4 ,we shall revert to this   
fact1 which is of  importance1          
presently4    ,fourth ,experiment4--,the
 following series of experiments were   

undertaken  to enable us to form some   
idea of the rapidity with which oxygen  
is  absorbed by wort4    ,we employed   
three flasks4 ,a1 ,b1 ,c1 of the        
following capacities3--        ,a  #bcd 
,b  #bad        ,c  #bjc    into which  
we introduced the following quantities  
of wort 7boiled wort1  without air73--  
,into ,a #if c4c4         8 ,b #hd 0    
8 ,c #hd 0    ,the necks of the flasks  
were then drawn out and sealed in a     
flame1 the  liquid being at a           
temperature of #e ,c4 7#da ,f474 ,the   
flasks were then  placed in a hot-water 
bath and kept at #ajj ,c4 7#bab ,f47 for
 a quarter  of an hour4 ,the flask ,a   
was repeatedly shaken during cooling1 as
 also  was the flask ,b1 this being     
omitted in the case of the flask ,c4    
,the contents of flask ,a were submitted
 to analysis as soon as it was  quite   
cooled--that is to say1 in about three  
hours4 ,the analysis of  contents of ,b 
and ,c was delayed for about twenty-four
 hours4 ,we took the  precaution of not 

commencing the analysis before we had   
shaken the  flasks for a few minutes1 so
 that the wort in all of them might be  
saturated at a fixed temperature1 and   
thus enable us to ascertain the  exact  
quantity of oxygen in solution4    ,the 
analyses showed that the worts in the   
three flasks contained3--        ,flask 
,a1 oxygen in combination1 per litre #bj
 c4c4          8 ,b1 0 8 0 #bad c4c4    
8 ,c1 0 8 0 #afh c4c4    ,several facts 
may be deduced from these experiments3  
the shaking up of  the wort with air has
 a marked effect on the absorption2 a   
very  appreciable absorption immediately
 follows the shaking up of the wort     
when warm2 whereas1 in the case of cold 
wort that has remained  undisturbed1 the
 absorption takes place slowly4    ,the 
results of the preceding experiments    
plainly show that the wort1  which is   
very hot when it comes on to the        
coolers1 where it remains for  several  
hours1 must absorb an appreciable       
quantity of oxygen by  combination2 but 

these same experiments teach us nothing 
definite  concerning the volume of      
oxygen that is actually absorbed4 ,we   
can only  gather from the remark which  
concludes the third experiment given    
above1  that the total quantity of      
oxygen absorbed by the wort in          
,tourtel's  brewery1 during the time    
that it remains on the coolers1 must be 
less  than #ag c4c4 per litre 7#dg cubic
 inches per gallon71 inasmuch as the    
coloration effected by combined oxygen  
in the proportion of #ag c4c4 per  litre
 was considerably greater than that of  
the wort taken from the  backs in the   
brewery4    ,if we knew the curve of    
cooling on the ,tourtonville coolers we 
might  easily1 in experiments conducted 
in our laboratory1 assimilate the       
conditions of our experiments to those  
of the oxidation of the wort in  the    
brewery1 by exposing wort in contact    
with air in closed flasks to            
temperatures varying according to the   
indications of the curve in  question4  

,for this purpose1 we induced ,m4       
,calmettes to study the process  of     
cooling upon the coolers at             
,tantonville4 ,in ,fig4 #hd the figures 
found  in one of that gentleman's       
experiments are given4    ,the absciss  
represent the time expressed in hours2  
the ordinates1 the  degrees of          
temperature4 ,the exterior temperature  
was #j ,c4 7#cb ,f472 the  atmosphere   
was calm4 ,the wort was pumped on to the
 coolers at #e4bj p4m41  its temperature
 then being #he ,c4 7#ahe ,f471 and the 
operation of  pumping lasted from #e4bj 
to #e4cj p4m4 ,the first determination  
was made  at #e4cj p4m41 and was        
repeated every ten minutes until #g4cj  
p4m4 ,between  #g4cj and #h4cj p4m4 it  
was repeated every twenty minutes2 after
 that1 it  was repeated every half-hour 
until #b a4m41 when the wort went down  
to  the fermenting vessels4 ,the mean   
depth of the wort was #he centimetres   
7#ca inches74    ,illustration3 ,fig4   
#hd4 ,curve of cooling of the wort on   

the coolers  7,december #ahth1 #ahge74  
,having determined the rate of cooling  
in the brewery1 we made the  following  
experiment3 a known quantity of wort    
from the copper--deprived1              
consequently1 of oxygen--in the same    
condition as when it comes on the       
coolers1 was put into a graduated1      
cylindrical vessel1 which was then      
closed with an india-rubber cork1 and   
placed immediately1 without being       
shaken1 in a hot water bath at #he ,c4  
7#ahe ,f474 ,another vessel similar  to 
the preceding one1 and having a         
thermometer passed through the cork1    
and immersed in the wort1 enabled us to 
observe the temperature4 ,the           
temperature was gradually reduced1 in   
exact accordance with the data of  the  
preceding curve1 until the water1 in the
 course of eight hours and a  half1 was 
brought down to #aj ,c4 7#ej ,f474 ,it  
is true1 that we cannot  pretend to have
 realized all the conditions of the     
coolers1 in this  manner1 but we        

approached them very nearly2 moreover1  
it was an  approximation rather than a  
rigorous determination that we desired  
to  obtain4 ,we then collected over     
mercury the air which remained in the   
flask1 and analyzed it very carefully2  
at the same time1 with  ,schtzenberger's
 apparatus1 we determined the oxygen    
held in solution in  the wort so        
treated4 ,from the results thus obtained
 we easily found the  quantity of oxygen
 that had disappeared--that is1 the     
oxygen which the  wort had acquired from
 the atmosphere of the flask1 and which 
had  combined with the oxidizable       
matters of the wort4    ,the volume of  
the flask being #hae c4c41 that of the  
wort #cia c4c41 and  the depth of the   
liquid #h cm41 we found an absorption by
 combination of  #idi c4c4 of oxygen per
 litre of wort 7#bfc cub4 ins4 per      
gallon74  ,another flask treated in the 
same manner gave us similar results4    
,as the oxygen in solution has so great 
an influence on fermentation1 it  is    

important that we should1 likewise1 know
 the effect produced by the  oxygen in  
combination4 ,the following             
considerations and experiments may      
throw some light on this subject3--     
,we have already remarked that natural  
saccharine worts oxidize1 and  acquire  
colour in contact with air1 and that    
this coloration disappears  when these  
worts are caused to ferment4 ,this      
furnishes one presumption1  that the    
oxygen in combination disappears then1  
from1 being abstracted  by the ferment4 
,a similar phenomenon is observable in  
the case of wort4  ,after having        
acquired a marked dark shade by         
remaining in contact with  pure air1 it 
loses this colour very appreciably      
during fermentation2 and  if the wort   
does not quite regain the colour which  
it originally had  when it came from the
 copper1 this circumstance is probably  
owing to the  fact that the quantity of 
oxygen in combination with the wort is  
larger  than that which is abstracted by

 the yeast4 ,we have seen that yeast    
absorbs oxygen1 since1 in the case of a 
saccharine wort1 more or less  saturated
 with oxygen in solution1 when          
fermentation commences1 the  first      
effect of the ferment is to cause that  
oxygen to combine with its  own         
substance4 ,we should1 therefore1 expect
 to find the oxygen in  combination1 as 
well as that held in solution1 in wort1 
abstracted by  the yeast and            
contributing to the activity of         
fermentation4 ,as a matter  of fact1    
this is proved by direct experiments1   
for the fermentation of a  wort that has
 oxidized in contact with air1 or of one
 from which all the  oxygen that was    
held in solution in it has disappeared  
by direct  combination1 is much more    
easy1 rapid1 and complete than the      
fermentation of the same wort when it   
contains no oxygen1 whether free  or    
combined4 ,these experiments were as    
follows3 we boiled some copper  wort in 
a large double-necked flask1 like those 

shown in ,fig4 #gc2 all  the air being  
expelled1 pure air was allowed to enter 
the flask2 and  when the wort was cool  
it was saturated with this air1 by being
 shaken  briskly for a quarter of an    
hour4 ,the wort was then forced by a    
pressure  of air1 applied to the        
extremity of the ,s-shaped tube1 into   
smaller  flasks1 similar to the         
preceding ones2 these we filled         
completely1 and  then plunged the end of
 their sinuous tubes under mercury4     
,after waiting  for two or three days1 a
 longer time than was required for the  
oxygen in  solution to enter into       
combination--a fact which we confirmed  
by means of  a similar flask1 which     
served as a standard--we caused the     
wort1 so  prepared1 to ferment in the   
flasks1 and side by side1 for the sake  
of  comparison1 some copper wort that   
contained no air in solution or         
combination4    ,in other experiments we
 operated on pure wort1 saturated with  
oxygen in  combination1 by being allowed

 to remain for one year in an open flask
 in  contact with pure air4 ,this wort  
was deprived of air in solution by a    
protracted boiling over mercury4 ,it was
 then pitched1 out of contact of  air1  
with an old yeast4 ,the yeast underwent 
no development at all1 a  proof that    
oxygen in combination cannot act like   
oxygen that is free1 or  simply in      
solution1 in effecting the revival of   
the yeast2 nevertheless1  after the     
revival has been once started by means  
of a small quantity of  air1            
fermentation declares itself with much  
greater facility than in the  case of   
copper wort1 placed under the same      
conditions1 but deprived of  oxygen in  
combination4        ,v4 ,on the         
,influence of ,oxygen in ,combination on
 the ,clarification of                  
,wort4      ,oxygen in combination has  
another effect which it is essentially  
important to point out1 for it concerns 
the clarification of beer4 ,one  of the 
most valued properties of this beverage 

is its limpidity and  brilliancy4 ,we   
know from the results of the fourth     
experiment in the  preceding paragraph  
that in the case of a wort shaken up    
when hot with  air1 and examined as soon
 as cold1 that is1 after an interval of 
only  three hours1 we find a notable    
volume of oxygen to have been absorbed  
by  combination2 in the experiment to   
which we allude1 this volume was not    
less than #bj c4c4 of oxygen per litre  
of wort4 ,the shaking up of the  wort   
when cold with air saturated it with    
oxygen in solution1 but the  quantity of
 oxygen which under these conditions    
entered into  combination1 in the course
 of three hours1 is insignificant1      
although  saturation by solution may be 
attained in the course of one minute's  
shaking4 ,if two samples of the same    
wort are shaken up with air1 one of     
them being hot and the other cold1 and  
both filtered after having been  left   
undisturbed for twenty-four hours1 or   
even immediately after the  agitation1  

we cannot fail to be struck with the    
great difference that  they will present
 in point of brightness4 ,the wort that 
was shaken up  hot will have more       
colour1 and will be brilliant2 the other
 will be  turbid1 and will not become   
clear for five or six days1 when left to
  itself in contact with air and        
filtered again4 ,this explains a fact   
that  may be easily verified in         
practice3 ,boiled wort1 if cooled down  
suddenly1 or slowly but out of contact  
with air1 or shaken up cold in  contact 
with air1 is opaque when filtered2      
whilst the same wort1 cooled  down on   
the coolers where it has taken a certain
 quantity of oxygen into  combination1  
generally passes through the filter very
 bright4 ,the  intelligent brewer is    
uneasy when this is not the case1 for it
 cannot be  denied that the easy        
clarification of wort has a favourable  
influence on  the easy clarification of 
beer4    ,it would1 nevertheless1 be a  
grave error to suppose that the         

clarification of beer must necessarily  
follow that of wort1 and we may  be     
permitted to make a digression here on  
the subject1 to prove this  statement4  
,on ,february #crd1 #ahgd1 we brewed #b 
hectolitres 7#dd gallons7 of beer4 ,the 
boiling wort1 hops and all1 was run into
 a vessel like that represented  in     
,fig4 #hj1 but provided in addition with
 a false bottom1 pierced with  holes and
 fixed at #a centimetre 7#jci inch7     
above the true bottom of the  vessel2   
this was meant to retain the spent hops4
 ,the temperature of the  wort in the   
vessel after it was filled1 ,february   
#crd1 #d p4m41 was #ij ,c4  7#aid ,f471 
that of the room was #aj ,c4 7#ej ,f474 
,we permitted the wort  to cool down    
gently1 without running cold water over 
the vessel4 ,the  wort indicated a      
density of #ad ,balling4    ,the        
following temperatures were taken3--    
,temp4 of               ,temp4 of       
,wort4                  ,room4          
,feb4 #d1    #aa a4m4 #ch   ,c4   7#ajjd

 ,f47 #i ,c4      7#dhb ,f47            
#g p4m4 #cj   ,c4   7 #hf   ,f47 #i ,c4 
7#dhb ,f47                #aa4cj p4m4   
#bfc ,c4   7 #gic ,f47 #i ,c4      7#dhb
 ,f47        ,feb4 #e1     #i a4m4 #ba  
,c4  7 #fih ,f47 #h   ,c4    7#dfd ,f47 
#ab a4m4 #aige ,c4  7 #fff ,f47 #h   ,c4
    7#dfd ,f47                    #d    
p4m4 #ah    ,c4  7 #fdd ,f47 #he ,c4    
7#dgc ,f47        ,feb4 #f1    #aa a4m4 
#ad    ,c4  7 #egb ,f47 #h   ,c4        
7#dfd ,f47        ,feb4 #g1     #b p4m4 
#aa    ,c4  7 #eah ,f47 #g   ,c4        
7#ddf ,f47    ,at the end of this time  
the wort drawn from the smaller tap     
half-way up  the vessel had already     
become very bright1 although it was     
taken from  the bulk of the liquid above
 the deposit of hops4    ,on ,february  
#hth the temperature of the wort was #ie
 ,c4 7#dia ,f471 and  that of the room  
#e ,c4 7#da ,f472 the wort was again    
very bright4 ,taken  from the small tap 
and tested by ,schtzenberger's process  
it gave no  evidence of free oxygen in  

solution1 although its surface was in   
contact  with air4 ,it continued        
absolutely pure1 the arrangements of our
 vessel1  as we have already explained1 
allowing only such air to enter as was  
first deprived of its disturbing germs4 
,not till ,february #abth1 after we had 
again determined the purity and         
brilliant clearness of the wort1 a      
brilliancy which we can compare with    
nothing so well as ,cognac1 without the 
faintest trace of cloudiness1 did  we   
set it to ferment in a vessel similar to
 that in which it had cooled1  but      
without the false bottom4 ,in the       
process of transfer we effected its     
aeration by causing it to fall on a     
small inverted tinned iron capsule  some
 #d or #e centimetres 7#a- to #b inches7
 in diameter4 ,by this  arrangement the 
wort took up air to the extent of rather
 more than a  third of its saturate     
capacity1 that is to say1 by spreading  
over the  capsule1 and falling from it  
in a kind of sheet1 it absorbed a volume

 of  oxygen more than a third of the    
total amount of oxygen which it was     
capable of absorbing at the existing    
temperature2 this was #ab ,c4 7#ecf     
,f47 at the moment when the wort was    
drawn off4 ,the pitching was            
accomplished with a #f-litre flask      
containing about #d litres 7#gjd pints7 
of beer that had been in 8low0          
fermentation from ,february #crd4 ,the  
beer  was cleansed on ,february #bdth1  
and had a density of #e-a_/d ,balling4  
,we  collected #bcde kilos 7#geci oz4   
troy7 of yeast1 containing #ef per      
cent41 that is1 #acac kilos 7#dbba oz4  
troy7 of pressed yeast1  containing #cfg
 per cent4 of yeast dried at #ajj ,c4   
7#bab ,f471 that is  #dhb grammes 7#aedi
 oz4 troy7 for the brew1 which would    
give #bda grammes  7#ggdh oz4 troy7 of  
yeast formed per hectolitre 7#bb        
gallons74    ,the beer was turbid when  
drawn off1 and the small glassful that  
we  removed did not brighten in         
twenty-four or even forty-eight hours4  

,the  samples for some days previously  
had been in the same condition4 ,the    
yeast existed as a fine deposit without 
any straggling yeast about the  sides4  
,the want of brightness was dependent   
rather on spurious colour  than on any  
actual turbidity4 ,we may here remark   
that if in the  preceding experiment the
 wort had taken up oxygen into          
combination as  well as into solution at
 the time that it was aerated1 the other
  conditions being the same1 the beer   
would have been bright and better4      
,it follows from this experiment that a 
wort may be perfectly bright at  the    
moment when it is pitched1 yet fail to  
produce a beer which shall be  bright   
when racked1 or one that will brighten  
subsequently otherwise  than with great 
difficulty4 ,we may add that when we    
repeated this same  experiment1 cooling 
the wort1 however1 as rapidly as the    
conditions of  our apparatus permitted1 
and employing iced water1 the beer      
appeared  very nearly bright when it was

 racked1 and brightened pretty quickly  
in  cask and in bottle4 ,the total      
duration of cooling was not longer than 
two hours4    ,the question here arises 
what part does the oxygen combined with 
wort  play in the clarification of the  
latter1 or in the clarification of      
beer8 ,although it may be difficult to  
give a definite answer to this          
question1 we must bear in mind that in  
cases where the beer brightens  best1 if
 we examine it under the microscope     
during fermentation1 we see1  besides   
the clusters of yeast-cells1 floating   
amorphous particles1 which  are larger  
and more compact than those to which the
 turbidity of worts  and muddy beers is 
due1 a circumstance which should lead us
 to suppose  that the oxygen in         
combination with the wort has the effect
 of modifying  the nature of the        
amorphous deposit which is produced     
during the  fermentation of the wort4   
,during boiling1 the hop yields to the  
wort a  variety of resinous1 odorous1   

and astringent substances1 which1 for   
the  most part1 are held in solution by 
the presence of sugar and dextrin4 ,at  
the moment when1 under the influence of 
the yeast1 which is itself more  or less
 oxidized1 the sugar becomes transformed
 into alcohol and  carbonic acid1 a     
portion of the bitter and resinous      
matters of the hop  becomes insoluble   
and remains in a state of suspension in 
the liquid4 ,it  is very probable that  
at this point it is when the combined   
oxygen  assumes its function of         
modifying the physical structure of     
these  insoluble particles1             
agglomerating them1 so that they become 
more easily  deposited4#agi             
,moreover1 oxidation tends to form a    
special precipitate in the wort1  which 
precipitate contributes towards the     
collection and deposition of  the very  
fine particles suspended in the wort1 by
 a mechanical action1  similar to that  
which we notice in fining operations4   
,on the coolers an  effect of this kind 

is produced4 ,the wort in the copper    
contains  insoluble matters which pass  
on to the coolers4 ,very bright when    
boiling1 it grows turbid as it cools1   
and then contains two kinds of          
insoluble substances3 #a4 ,substances   
insoluble alike in the hot and cold     
liquid1 some of which even1 as we have  
just seen1 are formed under the         
influence of heat and air3 all these    
substances precipitating rapidly to  the
 bottom of the vessels4 #b4 ,very fine  
particles insoluble in the cold1  but   
soluble in the hot liquid1 appearing as 
the wort cools down1 and  giving it a   
milky appearance4 ,if the air does not  
come into play they  remain in          
suspension for an indefinite time1 so to
 say4 ,wort taken  boiling from the     
copper and cooled down1 therefore1 forms
 a considerable  deposit at the bottom  
of the bottles4 ,now1 if we put this    
wort into  bottles without filling them1
 putting into some only the milky wort  
from  above the deposit1 and into others

 the same wort along with some of the   
deposit1 then raise it to #ajj ,c4 7#bab
 ,f471 and before it has time to  cool  
down shake it up with air a good many   
times1 it will be readily  seen that the
 wort in the bottles containing the     
deposit will brighten  more rapidly and 
satisfactorily than those in the bottles
 without the  deposit4 ,the deposits    
which are insoluble in the copper have1 
therefore1  an influence on the         
clarification4 ,we must add1 however1   
that this  influence cannot be compared 
with that of direct oxidation4    ,the  
8turning out0 of the wort and its stay  
upon the coolers to a certain  extent   
exhibit the different conditions which  
take part in its  clarification1        
inasmuch as the wort charged with its   
insoluble matters  is run off very hot1 
and with more or less violence against  
the external  air4                      
,,vi4--,application of the ,principles  
of the ,new ,process of ,brewing with   
the ,use of ,limited ,quantities of     

,air4      ,we have now an idea of the  
quantities of oxygen which occur1 free  
or  combined1 in the actual processes of
 manufacture4 ,we know1 moreover1  that 
an excess of air may be injurious1      
especially to the aroma of the  beer1   
and to that quality which consumers     
prize so highly1 which goes by  the name
 of bouche4 ,it must1 therefore1 be     
important to ascertain  whether in      
existing processes the proportion of    
active oxygen may not be  excessive4    
,the best practical means of determining
 this would consist in comparing  the   
products of different processes with    
progressively increasing access  of air1
 starting from none at all1 as in the   
case of cooling in the  presence of an  
atmosphere of carbonic acid gas4 ,the   
following  arrangement 7,fig4 #he7      
permits us to realize these             
conditions3--    ,illustration3 ,fig4   
#he4    ,the wort brought to a          
temperature between #ge and #hj ,c4     
7#afg and #agf  ,f47 in the             

double-bottomed vessel ,c1 passes by the
 tube a b into a  refrigerator1 such as 
,baudelot's1 for example1 but acting in 
an inverse  manner to the ordinary mode 
of using ,baudelot's2 that is to say1   
the  wort is made to circulate inside   
the tubes1 whilst the cold water plays  
on the outside4#ahj ,the wort when      
cooled1 its temperature being  indicated
 by a thermometer c1 passes down by the 
tube c,,dd to fill  the fermenting      
vessel ,a4 ,this vessel is made of      
tinned iron1 or1 better  still1 tinned  
copper1 and has a cover provided with a 
man-hole and  eye-hole2 m n one of the  
tubes for the circulation of air during 
fermentation2 its connecting-tube is not
 represented1 it would be behind  the   
vessel4    ,at the point d there is a   
pipe for admission of pure air2 this is 
represented on a larger scale at ,t4    
,the wort1 as it runs through the  large
 tube1 carries with it air from outside1
 and this air is calcined  on its way in
 by means of a flame which plays on the 

copper tube through  which it passes4   
,this arrangement supplies a third or   
more of the total  quantity of oxygen   
that the wort is capable of acquiring by
 solution at  the temperature at which  
we work4    ,f represents the           
arrangement of the reversed funnel in   
which the tube m  n terminates4 ,its    
mouth is closed with cotton-wool held in
 place  between two pieces of wire      
gauze1 for the purpose of purifying the 
air  that enters by it into the         
fermenting vessel during fermentation4  
v is an entrance tap for steam1 by means
 of which the vessel and  refrigerator  
are cleansed from all extraneous germs  
before each  fermentation1 and before   
the wort passes into the refrigerator4  
,when the fermenting vessel ,a is at    
work1 we may start a fermentation in  a 
second vessel in the following manner3  
opening a small tap situated at  about a
 third of the height of the vessel1 we  
pass a few litres of the  fermenting    
beer into a can of tinned copper1       

previously purified by a  current of    
steam1 and filled with pure air4 ,this  
can is then emptied  into the fresh     
vessel1 an operation of no difficulty1  
since we have  merely to connect the tap
 of the can with the small tap of the   
vessel1  and lastly1 the vessel is      
filled with wort1 which then mixes with 
the  fermenting liquid4 ,these various  
manipulations1 it is evident1 are       
performed under conditions of complete  
purity1 without the slightest  contact  
of the liquids either with the exterior 
air or with utensils  contaminated by   
disturbing germs4#aha    ,it is seldom  
that an industry adopts at once in their
 entirety new  practices which would    
necessitate a re-arrangement of plant1  
and the  process of which we are        
speaking would require such             
re-arrangement1 as  far as the          
fermenting vessels and the method of    
cooling the wort are  concerned4 ,the   
new process would1 however1 be of great 
value if once  introduced1 simply for   

the manufacture of pure ferment and pure
 wort1 or  even for that of pure ferment
 alone4 ,in other words1 we might retain
 the  ordinary methods employed in low  
fermentation1 use the same method of    
cooling or the new one1 the same        
fermenting vessels1 and the process of  
fermentation at low temperatures2 the   
yeast1 however1 would be prepared  in a 
state of purity in the closed vessel    
which we have described1  collected in  
those vessels1 aerated1 and then        
employed after the  old-established     
custom2 better still1 the pitching might
 be performed  with beer in the act of  
undergoing pure fermentation4    ,above 
the fermenting-stage there might be     
arranged a room for the  vessels used in
 the new process1 from which the pure   
beer could be run  for pitching purposes
 into the large tuns in the brewery     
below4 ,it is  true that beer prepared  
in this manner would not be perfectly   
pure1 but  from the results which have  
been obtained by working on this system1

  there is no doubt that it would       
possess keeping qualities far superior  
to those of beer made with ordinary     
yeast1 even supposing that beer to  have
 been treated with every possible       
precaution1 and to be as pure as  any   
produced in the best regulated          
breweries4    ,in the month of          
,september1 #ahgd1 we conducted an      
experiment at  ,tantonville1 in a closed
 vessel capable of holding #f           
hectolitres 7#acb  gallons74 ,the       
deposit of yeast served to pitch an open
 vessel1 the wort  of which had1        
moreover1 been cooled under conditions  
of purity4 ,the  cooling had been       
effected by means of the ,baudelot      
refrigerator1  represented in ,fig4 #he1
 the wort in the closed vessel having   
been  similarly treated4 ,for shortness 
sake1 we may designate the closed       
vessel and its beer by the letter ,k1   
and use the letter ,m for the open      
vessel and its beer1 and ,t for the     
corresponding beer of the brewery4  ,the

 vessel ,k was pitched on ,september    
#dth1 and racked on ,september #agth1   
the beer then showing a density of #ee  
,balling4    ,the beers ,k and ,m were  
sent to ,paris at the same time as some 
barrels of  the beer ,t1 brewed by the  
ordinary process2 and samples of these  
different beers1 which arrived on       
,october #bbnd1 were procured from five 
different cafs for purposes of          
examination4    ,the beer ,m did not    
suffer by comparison with the beer ,t4  
,the similarity  between the flavours of
 these two was so close as to puzzle    
even  experienced judges4 ,in both cases
 the beer was brilliantly clear4 ,in two
  cafs the beer ,m was even preferred to
 ,t1 being considered softer on the     
palate 7moelleuse7 and of more decided  
character 7corse7 than ,t1 a            
circumstance which may be explained by  
the fact that its wort had been  less   
aerated4    ,the beer ,k1 although very 
clear and bright1 was considered        
inferior to  ,m1 but the sole reason of 

this was that at the date when it was   
tasted--,november #crd--it did not      
froth4 ,as we have already remarked1 a  
peculiarity of the beers made in closed 
vessels is that their secondary         
fermentation takes a longer time to     
develop4 ,the yeast held in  suspension 
in the beer1 at the moment when it is   
drawn off1 is1 in the  case of all      
beers1 the yeast of a supplementary     
fermentation1 if we may  use that       
expression4 ,in the ordinary process of 
brewing1 this yeast1 in  consequence of 
the greater aeration of the wort at the 
commencement of  fermentation1 is more  
active1 or1 rather1 more ready to revive
 and  multiply than is that which       
develops in closed vessels4 ,if the     
barrels  of the ,k beer had been tapped 
on the #abth or #aeth of ,november1     
instead  of on the #crd1 it is probable 
that they would have contained as much  
carbonic acid gas as the beer ,m        
contained at the earlier date4 ,this    
delay in the resumption of fermentation1

 which characterizes beer made  in      
closed vessels1 is an advantage1        
inasmuch as it facilitates the          
transmission of the beer to long        
distances1 besides giving us the        
smallest deposits of yeast in cask or   
bottle1 as we have already pointed  out4
    ,in comparing the keeping qualities 
of the beer ,m and the beer ,t  7the    
latter being the brewery beer71 we made 
the following  observations3--#ahb      
,on ,november #beth we began to detect  
in the brewery beer an unsound  flavour2
 a large deposit1 too1 had formed2 the  
beer had lost its  brilliancy1 and      
frothed enormously4 ,the deposit swarmed
 with diseased  ferments1 especially    
those represented in ,nos4 #a and #g of 
,plate ,i4 ,the  beer ,m1 on the        
contrary1 was in brilliant condition1   
with an  insignificant deposit1 and an  
ordinary froth1 if anything1 rather     
small1  and beautifully bright4    ,on  
,december #crd the beer ,m was still    
good1 very clear1 and in excellent      

preservation2 it was considered by      
professional brewers as remarkably      
sound4    ,december #bbnd1 the same beer
 ,m was still very bright and good4     
,january #bjth1 the beer was still      
bright2 for the first time1 however1 we 
detected in the deposit in the bottles1 
which was still small1 the  filaments of
 turned beer4 ,this unsoundness was in  
its earliest stage4  ,now1 comparing the
 relative unsoundness of the two beers1 
we see that ,m  kept at least two months
 longer than the corresponding brewery  
beer4  ,this example shows us that as   
far as the keeping powers and the       
quality  of beer are concerned1 the     
existing process would gain considerably
 by  the employment of pure wort and    
pure ferment2 and1 indeed1 it seems     
likely that the new process may be      
introduced into breweries with this     
object in view4    ,in the course of the
 summer of #ahge we made the following  
observations  on the keeping qualities  
of a beer brewed on the new system1 all 

the  details of which had been          
rigorously carried out4 ,the beer brewed
 at  ,tantonville during the months of  
,june and ,july1 at a temperature of #ac
  ,c4 7#eed ,f471 in #ej-litre and      
#hj-litre casks 7#aa and #ah-;gallon71  
had  been sent by slow trains to ,arbois
 7,jura71 where we were staying for a   
time4 ,the temperature of the wine      
cellars in which these barrels were     
stored was1 on ,june #ast1 #abe ,c4     
7#ede ,f472 this rose gradually until   
,september #ast1 when it attained #ah   
,c4 7#fdd ,f474 ,in this cellar the     
brewery beer1 brewed in the ordinary    
way1 underwent change in the course  of 
fifteen days or three weeks1 whilst the 
beer brewed on the new system  remained 
sound for several months4 ,it is true   
that some of the barrels  lost their    
frothiness1 and that the beer in them   
underwent a peculiar  vinous change1 but
 these effects in no way depend on the  
conditions  peculiar to the new process4
    ,comparing the beers ,k1 ,m1 ,t1 of 

which we have been speaking1 we see     
that1 however useful the aeration and   
oxidation of the wort may be in         
quickening fermentation and facilitating
 clarification1 yet it is by no  means  
indispensable to the success of our     
operations that we should  introduce    
into our worts large quantities of      
oxygen1 whether by solution  or         
combination4 ,beyond a certain limit--a 
limit which is undoubtedly  overstepped 
in the existing process--oxygen is      
injurious to the palate  characteristics
 and aroma of beer4    ,these           
comparisons have proved to us that the  
new process can be applied  to wort     
aerated to the third of its             
saturate-capacity for oxygen1 and       
pitched with a good 8low0 yeast1 taken  
from the fermentation of a wort  aerated
 in the same way1 and that the beers    
thus obtained not only  possess vastly  
superior keeping properties1 but are    
equal in quality and  superior in       
palate-fulness to beers brewed with the 

same wort on the  existing system4 ,we  
should be perfectly justified in forming
 this  conclusion as to the strength#ahc
 of the beer furnished by the new       
process1 even if on tasting it we found 
that the new beer ,m was merely  equal  
in strength to ,tourtel's beer brewed in
 the ordinary manner1 since  the wort in
 the new process1 other conditions being
 the same1 is weaker  than the same wort
 treated in the usual way1 from not     
having undergone  that evaporation on   
the coolers which concentrates it4 ,if  
we were to  restore to the concentrated 
wort of ordinary brewing all the water  
lost  by it through evaporation1 the    
beer that we should obtain would be     
sensibly weakened4#ahd    ,one thing1   
however1 is that we must employ good    
varieties of 8low0  yeast4 ,we have seen
 how the employment of certain forms of 
yeast renders  the clarification of     
beers difficult1 as well as extremely   
slow1 and  almost prevents their falling
 bright at the end of fermentation4     

,these  yeasts1 moreover1 frequently    
impart to beer a peculiar yeast-bitten  
flavour1 which does not disappear even  
after a prolonged stay in cask4  ,even  
repeated growth of these yeasts1 whether
 in closed or in open  vessels1 and no  
matter what quantity of air we may      
supply them with  before fermentation1  
seems to have no effect in changing     
their  character4 ,the only thing we can
 do with these varieties of yeast is to 
get rid of them with all speed1 and to  
replace them with others4               
,notwithstanding the comparative success
 that has attended various trials  of   
the new process on the commercial scale1
 that process has not yet  been         
practically adopted3 and here we must   
bear in mind that we have not  to deal  
with any casual invention or mechanical 
improvement that could  be introduced   
all at once into the working of a       
brewery2 we are dealing  with operations
 of considerable delicacy1 which        
necessitate the adoption  of a special  

plant to carry them out4 ,under such    
conditions time and  labour are required
 to effect a change in the established  
processes of a  great industry4 ,this1  
however1 cannot diminish the confidence 
that we  have in the future of our      
process1 and it is our hope that the    
same  confidence will be shared in by   
all those who may give this work an     
attentive perusal4    ,footnote #afb3   
,m4 ,galland1 a brewer in ,maxville1    
near ,nancy1 published with his    name1
 in ,november1 #ahge1 a pamphlet1 which 
was reproduced in the    brewing        
journals of that date1 bearing the      
title1 ,it is said1 8the    air being   
impure1 let us exclude it20 ,i say1     
8,the air being impure1    let us purify
 it40 ,these two aphorisms1 together or 
apart1 constitute    the essential      
novelty of my researches on beer1 and   
,m4 ,galland is    mistaken in          
attempting to appropriate the merit of  
the second    alternative 7see my note  
in the ,comptes rendus of the #agth     

,november1    #ahgc1 and the text of the
 letters-patent obtained #acth ,march of
 that    year74 ,m4 ,galland has devised
 some arrangements for putting the      
latter    of these two schemes into     
practice2 but it is possible1 of course1
 to    effect this in a variety of ways4
 ,m4 ,velten1 a brewer in ,marseilles1  
had already accomplished this in his    
efforts to carry out practically    the 
procedure advocated in the present work4
    ,footnote #afc3                     
,non-technically1 stirred about4--,,ed4 
,footnote #afd3      ,as stated in the  
paragraph on arobian ferments1 in       
,chapter ,v41 8low0    yeasts1 to be    
preserved in their state of 8lowness10  
must be submitted    to often-repeated  
growths--every fifteen days in winter   
and every ten    days in summer1 that is
 to say1 they must be grown afresh after
 each    of these intervals4 ,if this is
 done1 there will be no reason to       
apprehend the formation of arobian      
ferments1 which1 as we have stated      

before1 may embarrass us by transforming
 our 8low0 yeasts into 8high0    yeasts4
    ,footnote #afe3      ,it has been   
observed by brewers that1 sometimes1    
without any apparent    cause1 a yeast  
suddenly becomes inactive and           
fermentation ceases4    ,accidents of   
this kind may probably be explained in  
the same manner as    the facts of which
 we are speaking4 ,if a wort has not    
been aerated1 or    if it has been      
deprived of oxygen by a commencing      
development of    microscopic organisms1
 the yeast formed in it will be very    
inferior1    and the fermentation may   
stop at its commencement or soon        
afterwards4    ,in such a case1 an      
aeration of the yeast and wort would be 
the best    remedy4    ,footnote #aff3  
,,pasteur1 ,comptes rendus de l',acadmie
 des ,sciences1 vol4 lii4 p4    #abfj1  
and tudes sur le ,vin1 #bnd ,edition1 p4
 #bgg4    ,footnote #afg3      ,we may  
here remark that the system of gutters  
in the above apparatus    is much       

simpler than that described in          
connection with ,figs4 #gf and    #gg4  
,the water which falls on the cover is  
carried off1 when the gutter    is full1
 by a circle of grooves1 inclined so    
that the streams running    from them   
meet and form more readily a sheet of   
water1 which flows    over the exterior 
surface of the cylindrical vessel4      
,footnote #afh3      ,it will be well   
for the reader to bear in mind1 that the
 word    8strength10 used by ,pasteur   
many times in this chapter1 has a       
different meaning to that which attaches
 to it in the minds of ,english         
brewers1 who in nearly every case use it
 in reference to original    gravity1   
while the author employs it1 in this    
chapter1 at any rate1    to denote the  
palate characteristic of strength1 in   
other words    palate-fulness4 ,for this
 reason we have thought it best in many 
cases to actually substitute the term   
8palate-fulness10 or 8body10 for    the 
literal translation of the ,french word 

8force40--,f4 ,f4    ,footnote #afi3    
,as some confusion has existed in the   
nomenclature of these salts1 it    may  
be as well to offer some explanation4   
,the salt here used for absorbing oxygen
 was discovered by    ,schtzenberger1   
and named by him hydrosulphite of soda4 
,it no longer    now goes by that name1 
being called hyposulphite of soda1      
,na,h,s,o#b4      ,the salts formerly   
known as hyposulphites are now called   
thiosulphates1 as ,na#b,s#b,o#c4        
,thus to put them together we have3--   
,hyposulphite 7,hydrosulphite7          
,na,h,s,o#b       ,bisulphite           
,na,h,s,o#c       ,thiosulphate         
7,hyposulphite7                         
,na#b,s#b,o#c      ,the thiosulphates   
were formerly regarded as containing the
 elements of    water in their          
composition1 thus3--,na#b;,h#b,s#b,o#d1 
which being    halved would give        
,na,h,s,o#b1 isomeric with hyposulphite1
 as ,pasteur    says4 ,it is further to 
be observed that ,pasteur uses the old  

notation1    in which the number of     
atoms of sulphur and oxygen are the     
double of    what they are in the       
new4--,d4 ,c4 ,r4    ,footnote #agj3    
,,sch,,tzenberger1 ,comptes rendus de   
l',acadmie des ,sciences1 vol4    lxxv41
 p4 #hhj4    ,footnote #aga3      ,m4   
,schtzenberger applies the term         
saturated to a solution of              
hydrosulphite prepared thus1 or very    
nearly so2 a current of    sulphurous   
acid is passed through a solution of    
commercial bisulphite    of soda1 to    
excess2 #ajj c4c4 7#c- fl4 oz47 of this 
solution and #cj    grammes 7#df grains7
 of zinc filings are put into a small   
flask1 so as    to completely fill it2  
the bottle is corked up and the mixture 
is    shaken briskly for about a quarter
 of an hour4 ,lastly1 the contents of   
this flask are poured into a large      
#b-litre flask1 with water and          
containing milk of lime1 prepared by    
mixing #ajj grammes 7#cb troy oz47    of
 quicklime in the water just before it  

is used4 ,the whole is shaken    briskly
 for some minutes and then left to      
settle4 ,the supernatant    liquid soon 
becomes bright4 ,this is the            
hydrosulphite2 but in this    state it  
is too concentrated2 and should be      
syphoned into another    #b-litre flask 
half full of water4 ,in the alkaline    
condition this salt    absorbs gaseous  
oxygen much less rapidly than in the    
acid1 so that the    liquids will retain
 their strength much longer1 if they are
 kept in    well-corked bottles4        
,footnote #agb3      ,the numbers n and 
n will vary as the wort1 or liquid which
 we    have to test1 is perfectly       
neutral or otherwise4 ,should it be acid
    n n1 should it be alkaline n n4     
,this would be a very exact    method of
 estimating the acidity or alkalinity of
 any coloured liquid4    ,footnote #agc3
      ,the ,balling saccharometer being 
almost unknown in ,england1 we may      
explain that its indications are for    
percentages of sugar in    saccharine   

solutions1 or of extract in worts2 #agi 
,balling1    therefore1 means #agi per  
cent4 of sugar or extract in the        
respective    liquids4--,f4 ,f4         
,footnote #agd3      ,experiments made1 
at our request1 by ,,mm4 ,calmettes and 
,grenet1 at    ,tantonville2 in         
,tourtel's brewery4    ,footnote #age3  
,see foot-note1 page #cfg4    ,footnote 
#agf3      ,for non-technical readers we
 may explain the expressions 8gathered10
    here used1 and 8turning out10 used  
on page #cfe4 8,turning out0            
describes the operation of emptying the 
copper contents into the    hop-back1 or
 the hop-back contents on to the        
coolers4    8,gathering0 refers to the  
time when the worts are finally         
intermixed    and weighed1 prior to the 
commencement of vinous                  
fermentation4--,f4    ,f4    ,footnote  
#agg3      ,we know also from the direct
 experiments of ,m4 ,schtzenberger1     
performed on aerated water with which   
yeast had been mixed1 that yeast        

causes all the oxygen in solution to    
disappear very quickly1 so that         
hydrosulphite gives no evidence of a    
trace4 7,see ,,sch,,tzenberger1         
,revue scientifique1 vol4 iii4 7#b71    
,april1 #ahgd74    ,footnote #agh3      
,the bottling needle 7foret  aiguille7  
is a contrivance for    permitting a    
cork to be driven into a bottle         
completely filled with    liquid1       
without bursting the bottle4 ,it        
consists of a    slightly-tapering iron 
pin about #a_/hth inch in diameter and  
#b inches    in length1 somewhat        
flattened1 and slightly curved          
throughout its    entire length1 with a 
groove running down one side from end to
 end1    the pin being jointed with a   
ring1 like a common ring cork-screw4 ,in
    using it the pin is driven into the 
bottle alongside the cork1 thus         
allowing the excess of liquid to escape 
as the cork advances4 ,when the    cork 
is completely home1 the needle is       
withdrawn1 and the elasticity    of the 

cork enables it to fill up the space    
left1 so that we have the    bottle     
corked air-tight1 and no air left       
between the cork and    liquid4--,d4 ,c4
 ,r4    ,footnote #agi3      ,we have   
remarked in our observations on ,no4 #f 
of ,plate ,i4 7p4 #f7 that    amongst   
the amorphous granular deposits of wort 
and beer we often find    minute balls  
of resinous and colouring matter1       
perfectly spherical and    very dense1  
which if the liquids be shaken up will  
render them very    turbid1 but which   
readily and rapidly deposit again1      
without remaining    in suspension in   
the least4 ,such then is the form in    
which the    deposits of wort in course 
of fermentation are precipitated1 when  
the    wort has been freely exposed to  
oxygen4 ,one day in the laboratory we   
were desirous of starting a fermentation
 in a vessel capable of    holding #ab  
hectolitres 7#bfd gallons74 ,but as we  
only had at our    disposal a copper    
capable of holding #b- hectolitres1 we  

procured the    wort from a neighbouring
 brewery in two barrels of #f           
hectolitres each4    ,this wort we      
re-heated1 in portions1 in our #b-      
hectolitre copper1 a    treatment which 
had the effect of oxidizing the wort    
more than it    would have been in the  
brewery4 ,in this case the beer fell    
remarkably    bright1 and the cells of  
yeast were accompanied by the deposit of
    minute agglomerations sketched in   
,plate ,i41 ,no4 #f4 ,we have repeated  
this experiment on a smaller scale and  
have obtained the same result4          
,footnote #ahj3      ,it is evident that
 this arrangement may be modified in    
many ways4 ,any    of the ordinary      
worms1 or1 generally speaking1 any of   
the more modern    refrigerators        
invented during the last few years1 may 
be adopted4 ,the    only point that is  
of importance is the preservation of the
 purity of    the wort during cooling4  
,the ,baudelot refrigerator is          
extensively adopted in ,france2 for this

    reason we used it in our experiments
 at ,tantonville4 ,we might equally     
well1 by enclosing the worm in a casing 
of sheet iron or tinned    copper1 pass 
our wort over the exterior of the tubes1
 the cold water    passing through them4
 ,the wort would cool quicker in this   
way than    with the arrangement        
described in the text1 and if we arrange
 to admit    only pure air into the     
case1 always under conditions of purity4
 ,the    aeration1 moreover1 could be   
made as much as we wished4    ,footnote 
#aha3      ,this arrangement limits the 
proportion of oxygen that may be        
introduced into the wort by direct      
oxidation4 ,but it would be easy to     
increase this at will1 by causing the   
wort as it comes from the copper    and 
the hop-back to pass into a cylinder    
turning horizontally on its    axis and 
furnished with blades fixed inside1 so  
as to divide the wort    and bring it   
better into contact with the air in the 
cylinder4 ,instead    of a revolving    

cylinder we might use a fixed vessel1 in
 which the wort    could be stirred up  
by some arrangement outside4 ,in either 
case we    should have to take care that
 the air was pure when it came into     
contact with the wort1 but this would be
 a matter of no difficulty2 we    would 
simply have to make communication with  
the outer air by means of    a tube     
filled with cotton wool4 ,any air that  
might be in the vessel at    the moment 
when the wort was introduced would be   
purified by the high    temperature of  
the wort coming from the copper4 ,we    
should1 moreover1    gain the great     
advantage of being able to bring oxygen 
to bear on our    wort in determinate   
amounts4 ,from this vessel it would pass
 on to the    refrigerator4 ,we might   
again raise the wort oxidized on the    
coolers to    a temperature of #ge ,c4  
7#afg ,f471 to recool it in this manner 
and    aerate it by means of the        
pure-air pipe4    ,footnote #ahb3       
,one of the barrels of the brewery beer 

was bottled about the end of            
,october1 at the same time that a barrel
 of ,m was4    ,footnote #ahc3          
,refer foot-note1 page #ced4            
,footnote #ahd3      ,the evaporation on
 the coolers varies according to the    
arrangements in    different breweries2 
but in no case is it less than several  
hundredths    of the total volume4 ,one 
special advantage of the new process is 
that    it gives us1 ceteris paribus1 a 
volume of beer that is #e1 #f1 or #g    
per cent4 greater than that which we    
should obtain by the old process1       
without in any way affecting the        
strength of the beer4 ,it is easy to    
ascertain the quantity that evaporates  
on the coolers1 by determining    the   
quantity of water that must be added to 
a known volume of wort    coming from   
the coolers to bring its density back   
exactly to that of    the original wort1
 both being calculated to the same      
temperature4    ,bate's ,english        
saccharometer1 which shows differences  

of nearly    #a_/ajjjth in density1 may 
be employed with advantage in this      
determination4                          
,,appendix4      ,whilst this work was  
passing through the press there appeared
 two small  works on the subject of the 
generation of inferior organisms4       
,one of them was by ,m4 ,fremy4 ,the    
author's object seems to have been      
merely to give an account1 under a new  
form1 of the part which he took  in the 
discussion on the origin of ferments    
that was carried on before  the ,academy
 of ,sciences in #ahga-ahgb4 ,in the    
course of that discussion  ,m4 ,fremy   
had announced his intention of          
publishing an extensive ,memoir1  full  
of facts1 bearing on the subject4 ,the  
perusal of the promised work  gave us   
much disappointment4 ,not only were our 
experiments1 and the  conclusions which 
we drew from them1 given there1 for the 
most part in a  manner which we could   
not possibly accept1 but1 moreover1 ,m4 
,fremy had  confined himself to         

deducing1 by the help of his favourite  
hypothesis1 a  series of  priori        
opinions based on half-finished         
experiments1 not  one of which1 in our  
opinion1 had been brought to the state  
of  demonstration4 ,to tell the truth1  
his work was the romance of             
hemi-organism1 just as ,m4 ,pouchet's   
work of an earlier date was the  romance
 of heterogenesis4 ,and yet1 what could 
be clearer than the  subject under      
discussion8 ,we maintain1 adducing      
incontestable  experimental evidence in 
support of our theory1 that living1     
organized  ferments spring only from    
similar organisms likewise endowed with 
life2  and that the germs of these      
ferments exist in a state of suspension 
in  the air1 or on the exterior surface 
of objects4 ,m4 ,fremy asserts that     
these ferments are formed by the force  
of hemi-organism acting on  albuminous  
substances1 in contact with air4 ,we may
 put the matter more  precisely by two  
examples3--    ,wine is produced by a   

ferment1 that is to say1 by minute1     
vegetative  cells which multiply by     
budding4 ,according to us1 the germs of 
these  cells abound in autumn on the    
surface of grapes and the woody parts of
  their bunches2 and the proofs which we
 have given of this fact are as  clear  
as any evidence can be4 ,according to   
,m4 ,fremy1 the cells of  ferment are   
produced by spontaneous generation1 that
 is to say1 by the  transformation of   
nitrogenous substances contained in the 
juice of the  grape1 as soon as that    
juice is brought into contact with air4 
,again1 blood flows from a vein2 it     
putrefies1 and in a very short time     
swarms with bacteria or vibrios4        
,according to us the germs of these     
bacteria and vibrios have been          
introduced by particles of dust floating
  in the air or derived from the surface
 of objects1 possibly the body of  the  
wounded animal1 or the vessels employed1
 or a variety of other  objects4 ,m4    
,fremy1 on the other hand1 asserts that 

these bacteria or  vibrios are produced 
spontaneously1 because the albumen1 and 
the fibrin  of the blood themselves     
possess a semi-organization1 which      
causes them1  when in contact with air1 
to change spontaneously into these      
marvellously active minute beings4      
,has ,m4 ,fremy given any proof of the  
truth of his theory8 ,by no manner of   
means2 he confines himself to asserting 
that things are as he says they  are4   
,he is constantly speaking of           
hemi-organism and its effects1 but we   
do not find his affirmations supported  
by a single experimental proof4  ,there 
is1 nevertheless1 a very simple means of
 testing the truth of the  theory of    
hemi-organism2 and on this point ,m4    
,fremy and ourselves are  quite at one4 
,this means consists in taking a        
quantity of grape juice1  blood1 wine1  
c41 from the very interior of the organs
 which contain  those liquids1 with the 
necessary precautions to avoid contact  
with the  particles of dust in          

suspension in the air or spread over    
objects4  ,according to the hypothesis  
of ,m4 ,fremy1 these liquids must of    
necessity  ferment in the presence of   
pure air4 ,according to us1 the very    
opposite  of this must be the case4     
,here1 then1 is a crucial experiment of 
the  most decisive kind for determining 
the merits of the rival theories1 a     
criterion1 moreover1 which ,m4 ,fremy   
perfectly admits4 ,in #ahfc1 and again  
in #ahgb1 we published the earliest     
experiments that were made in           
accordance with this decisive method4   
,the result was as follows3--,the  grape
 juice did not ferment in vessels full  
of air1 air deprived of its  particles  
of dust--that is to say1 it did not     
produce any of the ferments  of wine2   
the blood did not putrefy--that is to   
say1 it yielded neither  bacteria nor   
vibrios2 urine did not become           
ammoniacal--that is to say1 it  did not 
give rise to any organism2 in a word the
 origin of life  manifested itself in no

 single instance4    ,in the presence of
 arguments so irresistible as these1 ,m4
 ,fremy1  throughout the #bej pages of  
his work1 continues to repeat that these
  results1 which1 he admits1 seem       
subversive of his theory1 are1          
nevertheless1 explicable by the         
circumstance that the air in our        
vessels1 although pure at first1        
underwent a sudden chemical change when 
it came in contact with the blood1 or   
urine1 or grape juice2 that the  oxygen 
became converted into carbonic acid gas1
 and that1 in  consequence1             
hemi-organism could no longer exercise  
its force4 ,we are  astonished at this  
assertion1 for ,m4 ,fremy must be aware 
that1 since  #ahfc1 we have given       
analyses of the air in our vessels after
 they had  remained sterile for several 
days--for ten1 twenty1 thirty1 or forty 
days--at the highest atmospheric        
temperatures1 and that oxygen was still 
present1 often even in proportions      
almost identical with those to be  found

 in atmospheric air4#ahe ,why has ,m4   
,fremy made no allusion to  these       
analyses8 ,this was the chief1 the      
essential point in question4  ,besides1 
if ,m4 ,fremy had wished to test the    
truth of his explanation1  there was a  
very simple means of restoring the      
purity of the air in  contact with the  
liquids open to him2 he might have      
passed through his  vessels a slow and  
continuous current of pure air1 day and 
night4 ,we  have done this a hundred    
times1 and we have always found that the
  sterility of the putrescible or       
fermentable liquids remained unaffected4
    ,the hemi-organism hypothesis is1   
therefore1 absolutely untenable1 and we 
have no doubt that our learned friend   
will eventually declare as much  before 
the ,academy1 since he has more than    
once publicly expressed his  readiness  
to do so as soon as our demonstrations  
appear convincing to  him4 ,how can he  
resist the evidence of such facts and   
proofs8  ,persistence in such a course  

can benefit nobody1 but it may          
depreciate  the dignity of science in   
general esteem4 ,it would gratify us    
extremely  to find the rigorous         
exactness of our studies on this subject
  acknowledged by ,m4 ,fremy1 and       
regarded by that gentleman with the same
  favour bestowed upon it everywhere    
abroad4 ,it may be doubted if there     
exists at the present day a single      
person beyond the ,rhine who believes   
in the correctness of ,liebig's theory1 
of which ,m4 ,fremy's hemi-organism  is 
merely a variation4 ,if ,m4 ,fremy still
 hesitates to accept our                
demonstrations1 the observations of ,mr4
 ,tyndall may effect his  conversion4   
,the other publication to which we      
alluded was the work of the celebrated  
,english physicist1 ,john ,tyndall4 ,it 
was read before the ,royal ,society of  
,london1 at a meeting held on ,january  
#ac1 #ahgf4    ,the following letter    
explains how the illustrious successor  
of ,faraday  at the ,royal ,institution 

came to undertake these researches3--   
8,london1 ,february #af1 #ahgf4         
8,dear ,mr4 ,pasteur1--        8,in the 
course of the last few years a number of
 works bearing such      titles as      
#8,the ,beginnings of ,life'2           
#8,evolution and the ,origin of         
,life1' c41 have been published in      
,england by a young physician1 ,dr4     
,bastian4 ,the same author has also     
published a considerable number of      
articles in different reviews and       
journals4 ,the very circumstantial      
manner in which he describes his        
experiments1 and the tone of            
assurance with which he advances his    
conclusions1 have produced an           
immense impression on the ,english as   
well as the ,american public4      ,but 
what is more serious still1 from a      
practical point of view1 is      the    
influence that these writings have      
exercised on the medical      world4 ,he
 has attacked your works with great     
vigour1 and1 although      he has made  

but slight impression on those who know 
them thoroughly1      yet he has        
succeeded in producing a very great and1
 ,i may add1 a      very pernicious one 
on others4        8,the state of        
confusion and uncertainty had come to be
 so great      that1 about six months   
ago1 ,i thought that ,i should be       
rendering a      service to science1 and
 at the same time performing an act of  
justice to yourself1 in submitting the  
question to a fresh      investigation4 
,putting into execution an idea which ,i
 had      entertained for some six      
years1 the details of which were set    
forth      in an article in the ,british
 ,medical ,journal1 which ,i had the    
pleasure of sending you1 ,i have gone   
over a great deal of the ground      on 
which ,dr4 ,bastian had taken his stand1
 and1 ,i believe1 refuted      many of  
the errors by which the public had been 
misled4        8,the change which has   
taken place since then in the tone of   
the      ,english medical journals is   

quite remarkable1 and ,i am inclined to 
think that the general confidence of the
 public in the exactness of      ,dr4   
,bastian's experiments has been         
considerably shaken4        8,in taking 
up these researches again1 ,i have had  
occasion to refresh      my memory by   
another perusal of your works2 they have
 revived in me      all the admiration  
which ,i experienced when ,i first read 
them4 ,it is      my intention now to   
pursue these researches until ,i have   
dissipated      any doubts that may be  
entertained in respect to the           
unassailable      exactness of your     
conclusions4        8,for the first time
 in the history of science1 we are      
justified in      cherishing confidently
 the hope that1 as far as epidemic      
diseases      are concerned1 medicine   
will soon be delivered from empiricism1 
and      placed on a real scientific    
basis2 when that great day shall come1  
humanity will1 in my opinion1 recognise 
the fact that the greatest      part of 

its gratitude will be due to you4       
8,believe me1 ever very faithfully      
yours1        8,,john ,,tyndall40    ,we
 need scarcely say that we read this    
letter with the liveliest               
gratification1 and were delighted to    
learn that our studies had received  the
 support of one renowned in the         
scientific world alike for the  rigorous
 accuracy of his experiments as for the 
lucid and picturesque  clearness of all 
his writings4 ,the reward as well as the
 ambition of the  man of science        
consists in earning the approbation of  
his  fellow-workers1 or that of those   
whom he esteems as masters4    ,mr4     
,tyndall has observed this remarkable   
fact1 that in a box1 the sides  of which
 are coated with glycerine1 and the     
dimensions of which may be  variable and
 of considerable size1 all the particles
 of dust floating in  the air inside    
fall and adhere to the glycerine in the 
course of a few  days4 ,the air in the  
case is then as pure as that in our     

double-necked  flasks4 ,moreover1 a     
transmitted ray of light will tell us   
the moment  when this purity is         
obtained4 ,mr4 ,tyndall has proved1 in  
fact1 that to  an eye rendered sensitive
 by remaining in darkness for a little1 
the  course of the ray is visible as    
long as there are any floating particles
  of dust capable of reflecting or      
diffusing light1 and that1 on the other 
hand1 it becomes quite obscure and      
invisible to the same eye as soon as    
the air has deposited all its solid     
particles4 ,when it has done this1      
which it will do very quickly in two or 
three days1 if we employ one of  the    
boxes used by ,mr4 ,tyndall--it has been
 proved that any organic  infusions     
whatever may be preserved in the case   
without undergoing the  least           
putrefactive change1 and without        
producing bacteria4    ,on the other    
hand1 bacteria will swarm in similar    
infusions1 after an  interval of from   
two to four days1 if the vessels which  

contain them are  exposed to the air by 
which the cases are surrounded4 ,mr4    
,tyndall can  drop into his boxes1 at   
any time he wishes1 some blood from a   
vein or an  artery of an animal1 and    
show conclusively that such blood will  
not1  under these circumstances1 undergo
 any putrefactive change4    ,mr4       
,tyndall concludes his work with a      
consideration of the probable           
application of the results given in his 
paper to the etiology of  contagious    
diseases4 ,we share his views on this   
subject entirely1 and we  are obliged to
 him for having recalled to mind the    
following statement  from our ,studies  
on the ,silkworm ,disease3--8,man has it
 in his power to  cause parasitic       
diseases to disappear off the surface of
 the globe1 if1  as we firmly believe1  
the doctrine of spontaneous generation  
is a  chimera40    ,,the ,,end4         
,footnote #ahe3      ,see ,comptes      
rendus1 vol4 lxi41 p4 #gcd1 #ahfc4      
,,index4       ,a     ,absorption of    

gases by air-free liquids1 #bib         
oxygen by blood1 #ej2         by urine1 
#ej       from solutions by bacteria1   
#bie     ,acidity1 natural1 of wine a   
preservative1 #b1 and footnote     of   
beer heated1 #bj     action on ferments1
 #ce     ,acetate of lime from          
fermentation of tartrate1 #bhh          
,acid1 sulphuric1 facilitating          
filtration1 #bej     ,acid1 carbonic1 v4
 carbonic acid     ,adaptability of     
liquids to certain growths1 #cf1 #gc1   
#he     7supposed7 of vibrios to arobian
 or anarobian conditions1 #cji1 #caj    
,aeration1 reviving influence of1 #ach  
adoption by brewers of1 #bec     tardy1 
of wort in deep vessels1 #cdh     on    
8coolers10 its importance1 #cdh1 #cdi   
,aeration-conditions in ordinary brewing
 process1 #cej1 #cea1 #cfd1 #cfe        
,aeration of wort1 apparatus for        
regulating1 #ceb     ,aeration1         
influence on clarification of worts1    
#cha     experiments on its influence on
 growth1 #ajg1 #acj     ,arobian1       

definition1 #aaf     ferment1 growth of1
 #bjh1 #bji     ferments1 general       
characteristics1 #baj2       origin of1 
#baj 7footnote72       cultivation of1  
#baa2       aspects of1 #bab-bag2       
distinguishing features of1 #bah        
life in ferments overlooked1 #bfj       
8,age10 as applied to a ferment1 #afi   
,age of cells1 #bdf     ,aged aspect of 
exhausted cells1 #acc1 #adg     ,air1   
influence on ferment-life1 #bdb         
renewal of1 in brewers' yeast1 #bdf1    
#bdg     mode of expulsion from growing 
media1 #bhe     unnecessary to life of  
vibrios1 #bib     injurious to life of  
vibrios1 #cjd     ,air1 compressed1 and 
ferment-life1 #cbd     composition      
unaffected by contact with blood1 c41   
#cih     ,albumen-transformation theory 
of fermentation1 #bgc     ,albuminous   
liquids1 growth of yeast in1 #bfe       
,alcohol1 percentage is heated beer1 #bj
     ,alcoholic ferment1 minute species 
of1 #ga     ,alcohol1 detection in      
minute quantity1 #gh1 #gi 7footnote7    

produced by penicillium1 #ii1 and       
following pages       by aspergillus    
glaucus1 #aja1 and following pages      
by mycoderma vini1 #aaa1 #aac           
explanation of1 #aad     ,alcoholic     
fermentation1 general explanation of1   
#aad1 #aae     ,alcohol1 proportion of1 
to mucor forming it1 #acd1 and following
 pages     ,alcohol produced by moulds1 
#beh 7footnote7     production of1      
within fruits1 #bfg     ,alcoholic      
fermentation1 restricted meaning1 #bge  
7footnote7     necessary relation with  
yeast-cells1 #bge     ,altenaria tenuis1
 #aeg     ,ammonia1 a test for vegetable
 organisms 7,robin71 #cab               
,ammoniacal urine1 #de1 #df             
,anarobian1 definition1 #aaf     growth 
of yeast1 #bci1 and following pages     
precautions to be observed in1 #bdh     
life of fruit-cells1 #bgb     growth of 
vibrios1 #cjb     ,animal or vegetable  
nature of organisms1 #cab1 and following
 pages     ,anti-ferments1 #de          
,apparatus for sterilizing liquids1 #bg 

for producing pure beer1 #cdj1 c4       
for pure pitching1 #cdd     for pure    
aeration1 #ceb     for cooling beer with
 regulated supply of pure air1 #chh1    
#chi     ,appert's experiment1 #fb      
,aroma of beer destroyed by excess of   
air1 #cec     ,asbestos1 useful plug1   
#bg1 and footnote1 #cj     ,ascospores  
of yeast1 #aej 7footnote7     ,aspect of
 yeast variable1 #cg     ,aspergillus   
glaucus1 functioning as ferment1 #aja1  
and following pages     different       
aspects of1 #aje     ,atmospheric germs1
 #f1 #bf1 #ch     variety of1 #ci1 #gf1 
#hg 7footnote7     ,autonomy of         
organisms1 #hd 7footnote7       ,b      
,bacteria1 #ce1 #cf2     medium for     
growth of1 #bid2     absorption of air  
from solutions by1 #bie     ,bacteria   
and butyric vibrios1 how related1 #bif  
influence of oxygen upon1 #cje     ,bail
 mentioned1 #ib1 #ic1 #abg              
,balling saccharometer explained1 #cfc  
7footnote7     ,barley-wine1 #a         
7footnote71 #bcj     ,barley decoctions1

 experiments on development of ferments 
in1 7,fremy7      #bgc 7footnote7       
,bary1 ,de1 mentioned1 #ib2     on      
relations of yeast to other organisms1  
#ahj1 #aha     ,bastian's experiments1  
#djc     ,baudelot refrigerator1 #chg   
7footnote7     ,bavarian beer1 #aj      
,bchamp's microzyma theory1 #aba        
influence of air on fermentation1 #agh  
7footnote7     ,beer1 definition1 #a2   
difference between it and wine1 #a      
changeable nature of3 effects upon      
brewing purposes1 #b1 #c     two kinds  
only1 8high0 and 8low30 difference1 #g  
samples of bottled1 examined1 #bbb      
general precautions for pure manufacture
 of1 #cch     improved apparatus for    
commercial production1 #cdj1 and        
following        pages     ,beet root   
preservation in pits1 #bfi 7footnote7   
,berkeley mentioned1 #ib     ,bellamy's 
researches on fermentation in fruits1   
#bgj     ,berard on fermentation of     
fruits1 #bgj1 #bga     ,berthelot's mode
 of isolating inverting constituent of  

yeast1 #cbb      7footnote7     ,bert1  
action of compressed air on ferments1   
#cbd     ,birds1 experiment upon1       
described1 #cji     ,bistournage1 #dc   
7footnote7     ,bisulphite of lime used 
by bottlers1 #ae     ,blood1 study of   
sterilized1 #di1 #ej                    
,blood-crystals1 #ej 7footnote7         
,boiling sterilizes liquids1 #cd        
,bottling needle1 #cgb 7footnote7       
,bottled beer1 treatment of1 #af        
,bouche influenced by presence of       
oxygen1 #chg     ,bouchardat1 #cbc      
,brefeld1 strictures on ,pasteur's      
theory criticised1 #bhj     convinced of
 truth of ,pasteur's theory1 #cae1 #caf 
,breweries1 statistics of1 #aj          
,brewing1 change in processes of1 #g    
practices largely empirical1 #bbb       
,brewing processes under conditions of  
purity1 #cij     ,budding1 rate of1     
experiment on1 #ade     process of1 #adf
     ,buffon's hypothesis mentioned1    
#aba     ,bulbs1 glass1 for study of    
growths1 #aef 7footnote7     for        

vibrios1 #bih     ,bunsen1 tables of    
solubility of oxygen in water1 #cfj     
,butyric vibrios in must1 #fe2     in   
wort1 #gj     ,butyric acid from        
fermentation of lactates1 #big     not a
 suitable food for vibrios1 why81 #cja  
7footnote7     ,butyric fermentations   
yield variable products1 #cjh       ,c  
,cagniard ,latour1 on cause of          
fermentation1 #fj     ,calmettes1 ,m41  
#cfi1 #cga2     experiments on the curve
 of cooling of wort1 #cgg1 #cgh         
,carbolic acid for purifying yeasts1    
#bcb     ,carbonate of lime crystals    
formed in fermentation of lactate1 #bid 
,carbonic acid1 influence on            
preservation and fermentation of fruits1
      #bfh     evolution from           
fermentation of tartrate of lime by     
vibrios1 #bhg     amount of evolution1  
#bhh     mode of collection of1 #bhh    
influence on bacteria1 #cje 7footnote7  
,caseous ferment1 occurrence1 #bjj2     
aspect1 #bja2     endurance of heat1    
#bjc 7footnote72     meaning of title1  

#bjb2     origin of in brewers' high    
yeast1 #bjc1 #bjd2     origin of in     
,english pale ale1 #bjd1 #bbd2          
arobian form of1 #bae     ,cells1 power 
of endurance1 #acd     aspect of dead1  
#aci 7footnote7     ,cells1 glass1 for  
study of growths1 #aee 7footnote7       
,cells1 probable function in elaborating
 proteic matter1 #cce     ,cellulose1   
not soluble in ammonia 7,robin71 #cab   
,change of yeast1 usual remedy for      
disease1 #bb     ,chauveau on           
castration1 #dc     ,circumstances      
modifying nature of germs present in    
atmosphere1 #gc1 #hg      7footnote7    
,cladosporium1 #ee 7footnote7           
,clarification of liquids by fungi1 #ff 
7footnote7     of wort1 #cha1 and       
following pages     of a wort and its   
beer not always correlated1 #chb1 #chc  
,cohn's medium for growth of vibrios1   
#bid 7footnote7     ,colour darkened by 
oxidation in pure liquids1 #eg          
,coloration of vibrio-fermented liquors1
 #bia     ,colpoda1 #ci1 #dj            

,composition of medium1 influence on    
life1 #bif     ,conidia1 definition1    
#acg     ,conditions affecting the      
ferment character of cells1 #bff        
,consumption of beer in ,france1        
statistics1 #ag 7footnote7              
,contagion and ferments1 #da1 and       
following pages     ,continuity1 non-1  
of germs in air1 #fb     ,continuous    
vital activity of cells1 #bgh           
,contact-action1 theory of1 #cbf        
8,coolers10 importance in aeration of   
wort1 #cdh1 #cdi     influence on worts1
 #cfd     ,cooling of wort must be rapid
 in ordinary brewing1 #b     artificial 
of 8low0 beers1 #ab     ,cooling of wort
 in presence of carbonic acid1 #cdb2    
difficulties of the process1 #cdf1 and  
following pages     ,corpuscles on      
grapes and stalks1 #ed     ,corpuscles  
refractive in bodies of vibrios1 #cjj1  
v4 also cysts     ,correlation of       
special germs with special fruits1 #fa  
of special ferment and fermentation     
product1 #bgg     ,cotze and ,feltz1 #dc

     ,crushers for the vintage1 #bfh    
7footnote7     ,cream of tartar1 v4     
tartrate     ,cultivation of yeast under
 conditions of purity1 #bi-cb     of    
pure penicillium1 mode of1 #hh1 and     
following pages     of arobian ferments1
 #baa1 and following pages       ,cysts 
of vibrios1 #cjf1 #cjg       ,d         
,davainne1 on splenic fever1 c41 #db    
,daughter-cells1 #adf     ,dead cells1  
aspect of1 #aci 7footnote7     ,declat's
 treatment of infectious diseases1 #dd  
,dematium1 #afg2     resemblance to     
,saccharomyces pastorianus1 #agi1 #ahj1 
#aha1 #bad     resemblance to 8caseous0 
yeast1 #bja     ,degrees1 ,balling1 v4  
,balling     ,deposits1 amorphous1 of   
wort1 #f1 #aic1 #che1 and footnote      
,deterioration of beer correlated with  
presence of foreign organisms1      #bf1
 #cb     ,differential vitality1 a means
 of separating ferments1 #bbf           
,difficulty of experiments on growths1  
#fc1 #he       ,disease-ferments1 what  
they are1 why so called1 #d             

classification and account of1 #e1 #f   
origin of1 #f     inactive at low       
temperatures1 #ad     often found only  
in deposits1 #bd     not everywhere in  
atmosphere1 #ca     ,disease-germs      
usually latent1 #bbj     development in 
bottled beer1 #bbb     ,diseases of wort
 and beer1 meaning of1 #ai     mode of  
proving the cause of1 #ai1 #bj          
,diseased beer always result of disease 
ferments1 #bf     ,distribution of germs
 limited1 #fa     ,division1            
fissiparous1 of vibrios1 #bii     ,dried
 yeast1 #ha     ,dryness decreases      
sensitiveness of moulds to heat1 #ce    
,dumas1 distinction between organized   
and unorganized ferments1 #cbc          
,dust1 atmospheric1 contains            
disease-germs1 #f1 #bf     on fruits1   
experiments with1 #aec1 and following   
pages     when fertile1 #aeg1 and       
following pages     ,dutch yeast1 #bjj  
,duval1 ,jules1 experiments on          
transformation of ferments illusory1 #cg
       ,e     ,efflorescence of         

fermented liquors1 #ajh1 #aag           
,egg-albumen1 experiments on1 #ea       
,egypt1 beer first brewed in1 #ag       
,empiricism in ordinary brewing1 #bbb   
,energy stored by cells1 #acc1 #acd     
,endogenous sporulation of yeast1 #aej  
7footnote71 #agb     ,english beers all 
8high10 #g     temperatures and yeast   
employed1 #h 7footnote7     breweries1  
usages of1 #h 7footnote71 #ad           
,errors1 causes of1 v4 experimental     
errors     ,equations of fermentations  
variable1 #bgf1 #bgg     ,examination of
 deposits1 mode of1 #ba 7footnote7      
,exhaustion1 definition of1 #aga        
7footnote7     ,exhausted vibrios1 #bij 
,experimental errors1 #fc1 #he1 #ib     
avoided by use of double-necked flasks1 
#abj     ,experiments1 exactness of     
,pasteur's1 #ie 7footnote7     to prove 
connection between quality of ferment   
and quality of beer1        #bf1 and    
following pages     on living fluids1   
#dg1 and following pages                
comparative1 on pure must and must with 

corpuscles boiled and        unboiled1  
#ed1 and following pages     by         
,gay-,lussac on must1 #fb1 #fc     by   
,pasteur after ,gay-,lussac1 #fd     on 
distribution of ferments1 #fe1 and      
following pages     on distribution of  
fungus-spores1 #fh     in wide shallow  
dishes1 #fi1 and following pages        
comparative on germs in air1 #gb1 and   
following pages     with                
non-fermentative species of torula1 #gh 
on spontaneous impregnations1 #fe1 #ff1 
#fi1 #gc1 #gi1 #hg 7footnote7     on    
spontaneous fermentation1 #ahd     on   
dried yeast1 #ha1 and following pages   
on influence of aeration on growths1    
#ajg     on aeration and its absence1   
#acj1 and following pages     on        
function of oxygen on ferment-life1     
#bch1 and following pages     on the    
capacity of yeast for oxygen1 #bee      
on influence of carbonic acid on fruits1
 #bfh     on growth of vibrios apart    
from air1 #bhe     on fermentation of   
lactate of lime apart from air1 #bib1   

and following        pages     on       
influence of air on vibrio-life1 #cjc1  
#cjd     on influence of air on         
bacterium-life1 #cje     on gradual     
adaptability of organisms to adverse    
life-conditions1 #cji     on influence  
of air on fermentation1 #cdi     on     
solubility-coefficients of wort for     
oxygen1 #cfa-c       of brewers' worts1 
#cff1 and following pages     on        
combination of oxygen with worts1 #cga1 
and following pages     on the rapidity 
of the combination1 #cgf     on amount  
of combination1 #cgi     on             
non-transformation of mycoderma vini1   
#aaj1 and following pages1        #aac  
7footnote7       of mycoderma aceti1    
#abd1 and following pages       of mucor
 racemosus1 #abh1 and following pages   
on non-transformation of yeast into     
penicillium1 #ccc-cce     on cultivating
 pure penicillium1 #hh1 and following   
pages     on its transformation into    
yeast1 #ia     transformation1 ,trcul's1
 details of1 #ih     with submerged     

aspergillus1 #aja1 and following pages  
penicillium1 #ii     in disproof of the 
hemi-organism theory1 #bgc 7footnote7   
on growth of mixed moulds1 #aab     on  
purification of mixed ferments1 #bbf1   
and following pages     on growth of    
mucor mucedo1 #adj1 #ada     on         
proportion between weights of mucor and 
alcohol formed1 #acd1 and               
following pages     on the anarobian    
cultivation of yeast1 #bci1 and         
following pages     on variation of     
proportion of sugar used to yeast       
formed1 #bdi     on growth of yeast in  
sugar solutions1 #cah1 and following    
pages1        #cca-ccc     on dust on   
fruits1 #aec1 and following pages     on
 seasonal influences on fertility of    
dust-germs1 #aeg1 and following         
pages     on exhaustion of yeast1 #afi1 
and following pages       of 8high0     
yeast1 #ahi1 #aij     on revival of     
yeast1 #bjg1 #bjh     on cultivation of 
arobian ferment1 #baa1 and following    
pages     on gradual senescence of      

yeast1 #bde     on production of a pure 
beer1 #cch1 and following pages     on  
clarification of worts and beers1 #chb1 
and following pages     comparative1 on 
the qualities of beers brewed by        
different processes1        #cia        
on rate of budding1 #ade                
,exportation of 8high0 beers            
unsatisfactory1 #af       ,f            
,ferment1 v4 also yeast     ,ferments of
 disease1 v4 disease-ferments           
,ferments1 special1 #ad1 #ae            
,ferments and animal diseases1 #da1 and 
following pages     butyric1 lactic1    
alcoholic1 #gb     moulds functioning   
as1 #ajj1 #aja1 and following pages1    
#aaa1 #aac1 #abi1        #acc           
general character of a1 #aae     of     
grape1 varieties1 origin1 #aej1 and     
following pages     alcoholic1 summary  
of1 #aif     intermixture of1 #bbd1 #bbe
     mode of separation of mixed1 #bbf  
and following pages     succession of1  
in must1 #bbg     exceptional vital     
processes of1 #bcf1 #bcg     ,ferment   

power in relation to time discussed1    
#beb     character1 how related to heat1
 #bgj     and fermentation correlated1  
#bgg     a chemical substance existing  
in cells 7,traube71 #bhc 7footnote7     
of tartrate of lime1 #bij               
,ferments1 two classes1 distinctive     
characteristics1 #cbc     ,fermentation1
 rapid1 inexpedient1 #c     spontaneous1
 in case of must1 #d     8top0 and      
8bottom10 v4 8high0 and 8low0     masked
 by moulds in shallow vessels1 #ge      
7footnote7     by penicillium 7,troul7  
#id     by mycoderma vini1 #aaa1 #aac   
by mucor racemosus1 #abi1 #aci          
alcoholic1 general explanation of1 #aad1
 #aae     conditions of1 in sweetened   
mineral liquids1 #baa     without air1  
#bdb     with and without air1 results  
compared1 #bdc1 #bdd     a cell-life    
without air1 #bei     a general         
phenomenon1 #bff1 #bfg     of fruits not
 truly 8alcoholic10 #bgf     not        
definable1 according to ,brefeld1 as    
life without air1 #bhj     of lactate of

 lime1 #bid     ,fermentative energy1   
#beb     character dependent on         
conditions1 #bff     ,filamentous tissue
 7,turpin71 #abc     ,fitz on           
fermentation1 #adb     ,fissiparous     
division of vibrios1 #bii     ,flask    
sterilizing1 #bg1 #bi     ,flasks with  
double necks1 advantage of1 #abj        
,fluid1 ,raulin's1 #hh 7footnote7       
,flavour dependent on ferment species1  
#bcj     ,foreign organisms correlated  
with unsound beer1 #bf1 #cb     greatly 
promoted by adaptability of liquids1 #cf
     ,formula for solubility-coefficient
 of any wort for oxygen1 #cfd           
,fremy's statement of hemi-organism1 #eb
     answer to ,pasteur's facts1 #eh    
explanation of vintage fermentation1    
#bgb     8organic impulse10 #cbe        
latest assertions1 #cif-cii     ,fruits1
 ferment organisms on surface of1 #aec1 
and following pages     internal        
fermentation of1 #bfg1 and following    
pages     yeast cells not present       
within1 #bfg 7footnote7     influence of

 carbonic acid gas on preservation of1  
#bfh     respiratory processes of1      
according to ,brard1 #bgj               
fermentation within1 ,lechartier and    
,bellamy1 #bgj     crushed and          
uncrushed1 fermentation of1 #bgd        
,fruit-cells1 anarobian life of1 #bgb   
,fungi1 wide distribution of spores1 #fh
     absorption of oxygen by1 #beg      
production of alcohol by1 #beh          
7footnote7     ,fungoid manner of growth
 of well-aerated yeast1 #bea       ,g   
,galland's claims of priority1 #cch     
7footnote7     ,gay-,lussac's           
experiments on grape-juice1 #ei1 #fj    
,gayon's experiments on egg-albumen1 #ea
     8,gathered10 #cfg 7footnote7       
,generation1 theories of1 contrasted1   
#cig       ,germs of ferments in air1   
c41 #f1 #bf1 #ch     brought by other   
matters1 #ch     absent from fruits1    
when8 #eh1 #ei1 #aeg1 and following     
pages     not universally distributed1  
#fa1 #fc1 #aha 7footnote7               
distribution experiments1 #fe1 and      

following pages1 #hg 7footnote7     and 
their correlated fruits1 #fa     of     
disease latent1 #bbj     ,germ1 use of  
term by ,pasteur1 #cac     ,germ theory 
of disease discussed1 #df1 #dg          
,globuline tissue 7,turpin71 #abc       
,globulines1 punctiform1 #aba1 and      
following pages     ,globules1 #bge     
7footnote7     ,glycerine1 fermentation 
of1 by vibrios1 #cjf1 #cjg              
,gosselin1 ,m41 report1 #dd     and     
,robin on ammoniacal urine1 #de         
,gramme1 value in grains1 #ace          
7footnote7     ,granules in wort1       
explanation of1 #ie     ,graham's1 ,dr41
 criticisms of ,pasteur1 #ac 7footnote71
 #aif 7footnote7     ,graham1 ,dr41 on  
aspect of bottom yeast1 #aid 7footnote7 
,grape juice1 experiments on1 #eg1 #ei  
,grape-ferments1 v4 ferments            
,grapes1 do they contain cells of yeast8
 #bfg     ,greasiness of mycoderma vini1
 #hj1 and footnote       ,h     ,hallier
 mentioned1 #ib     ,hard water1        
influence on aspect of yeast1 #aid      

7footnote7     ,head of vibrio1 #bib    
,heating sufficient as preventing       
deterioration of liquids1 #bj           
influence on beer1 #bj     ,heat1       
production of1 its relation to          
ferment-power1 #bgj     ,hemi-organism1 
chimerical1 #ec1 #afb1 #cii1 #bgc       
7footnote7     latest assertions by     
,fremy on subject of1 #cif-cii          
theory of vintage-fermentation1 #bgb1   
#bgc     ,heterogenesis1 facts against1 
#ea       8,high0 fermentation1 meaning 
of1 #h1 #i     beers1 disadvantages of1 
#ab1 #ac     ferment1 aspect of1 #ahh1  
#ahi     characteristics of1 summary1   
#aia     ferment 7new71 occurrence1 #aih
       aspect and characteristics of1   
#aii       arobian form of1 #baf        
,high yeast1 arobian form1 aspect of1   
#bad     ,hoffmann1 ,h41 transformation 
of ferment1 #ib1 #ic     ,hop-oil as a  
beer-antiseptic1 #af1 and footnote      
,hopping influence on growths qu        
temperature1 #if     ,hot countries1    
absence of breweries in #af             

,hydrogen from vibrionic life1 #cjj     
occasional absence in butyric           
fermentations1 #cjh       ,hydrosulphite
 of soda1 composition1 use in           
determinations of oxygen1      #cee1 and
 footnote     preparation of saturated  
solution1 #ceg 7footnote7               
alterability of solutions of1 #cef      
improved method of ,m4 ,raulin1 #cef1   
and following pages       ,i     ,ice1  
quantities consumed in 8low0 breweries1 
#aa     ,illusions as to absence of     
foreign organisms1 #cf1 #he1 #ib        
,impregnations1 spontaneous1 #fe1 #ff1  
#fi1 #gc1 #gi     ,impregnation1 mode of
 7penicillium glaucum71 #hf             
,impurity of ferments1 source of        
experimental errors1 #cg     of yeast   
masked for a time1 #bbj     ,increase of
 yeast disproportionate to sugar used1  
#bcg     ,infusions1 nature of organisms
 in1 #ci     ,infusoria1 #ce            
,insoluble substances in wort1 #chf     
,inverting constituent of yeast1 #cba1  
and footnote     ,isolation of ferment1 

#gg       ,l     ,lactic ferments1 #e1  
#cf     transformation from and into    
other ferments 7,duval71 #cg            
,lactate of lime1 fermentation of1 #bib 
,lechartier and ,bellamy1 researches on 
fermentation in fruits1 #bgj            
,leptothrix1 #cf     ,liebig's views of 
fermentation1 #cag1 and following pages 
on fermentation of malate of lime1 #cba 
definition of a ferment1 #cbd           
modified theory1 #cbf2       answer to1 
by ,pasteur1 #cbf1 #cbg     neglect of  
microscopical observations1 #cbi1 #ccj  
,lime1 bisulphite1 use of1 by bottlers1 
#ae     carbonate sterilized1 use of in 
growths1 #abf     dextro-tartrate1 #bhd 
acetate and metacetate1 #bhh            
lactate1 fermentation of1 #bib          
,lister's1 ,prof41 letter on            
germ-theory1 #dc     ,london breweries1 
usages of1 #h 7footnote7     ,pasteur's 
visit to1 #bb-bd       8,low0           
fermentation1 meaning of1 #i1 #aj2      
advantages1 #ab     beer breweries1     
statistics of1 #aj       properties of1 

according to ,dr4 ,graham1 #ac     yeast
 and 8high0 yeast distinct1 #aib1 #aic  
yeast1 aspect of1 #aic2                 
characteristics1 #aie       arobian form
 of1 #bae     ,low temperatures         
prejudicial to disease-ferments1 #ad    
,m     ,malignant pustule1 #db          
,mashings1 #c     ,medium1 mineral1 for 
growing lactic vibrios1 #bic1 #big      
7footnote7     ,cohn's formula1 #bid    
7footnote7     for growth of bacteria1  
#bid     ,medium1 composition of1       
influence on life1 #bif                 
,microscopical study of yeast important1
 #bc     formerly neglected in ,english 
breweries1 #bb-bd     ,microscopical    
examination of vibrios1 #bih1 #bii      
,microzyma1 #aba2     source of         
mycoderma aceti according to ,bchamp1   
#abd     ,milk1 temperature of          
sterilization of1 #cd     ,milk-sugar1  
growth of yeast in1 #bfe     ,mother of 
vinegar1 v4 mycoderma aceti     ,moulds 
thrive in acid liquors1 #cf             
functioning as ferments1 #ajj1 #aja1 and

 following pages1 #aaa1 #aac1           
#abi1 #acc     growth of1 and production
 of alcohol1 #beg1 #beh 7footnote7      
suggested employment of1 industrially1  
#bfa     ,mucedines1 #cf1 #dj     ,mucor
 mucedo and racemosus on must1 #ff      
,mucor racemosus1 different aspects of1 
#aje     pure growth of1 #abh1 and      
following pages     ,mucor normal1      
growth of1 #acb     weight of to alcohol
 formed1 #acd1 and following pages      
morphology of abnormal growth1 #acg     
,mucor mucedo distinguished from        
racemosus1 #adj     growth in           
double-necked flasks1 #adj1 #ada        
,mntz1 #cbc     ,must1 fermentation of1 
always regular1 #c     pure fermentation
 of1 #ed1 and following pages           
succession of ferments in1 #bbg1 #bbh   
,mycelium and mycoderma vini on wine1   
#ef1 #fe     ,mycoderma in wort         
experiments1 #gj     ,mycoderma vini1   
arborescent form of1 #gg     growth of  
pure1 experiments on1 #aaj1 and         
following pages1 #abj     growth with   

penicillium1 #aab       with mucor1 #aab
     endogenous sporulation1 #aea       
7footnote7       ,mycoderma aceti       
transformations 7,bchamp71 #abd     pure
 growth of1 #abd1 and following pages   
,n     ,nageurs used in low             
fermentation1 #i     ,nature of liquids1
 influence on growths1 #cf1 #gc1 #he    
,natural liquids for pure growths1 use  
of1 #dj1 #da     experiments on1 #dg1   
and following pages     ,neutrality1    
conditions of1 as affecting             
sterilization of liquids1 #cd2          
explanation of fact1 #ce                
,neutralization of acidity in pure      
growths1 mode of1 #abf     ,new high    
ferment1 v4 high     ,new process of    
brewing1 #cia-cic     ,nitrogenous      
soluble parts of yeast1 #cai1 #cbj      
,nomenclature used by ,pasteur purposely
 vague1 #cad     ,normal growth of      
mucor1 #acb       ,o     ,organic       
substances1 have they any tendency to   
become organized8 #cc     ,organic      
liquids sterilized by boiling1 #cd      

,organizable globulines 7,turpin71 #abc 
,organisms and animal diseases1 #db     
,ouillage1 #b     ,oxidation of         
germ-free liquids1 #eg     processes of 
fungi1 #bfa1 and footnote     of wort1  
excessive1 injurious1 #cec1 #ced        
,oxygen absorbed by blood1 #ej       by 
urine1 #ej     and fermentation1        
according to ,gay-,lussac1 #fj          
store-energy imparted to cells by1 #acd 
no influence upon fermentation1         
7,bchamp71 #agh 7footnote7     function 
in fermentation1 experiments on1 #bch1  
and following pages     influence on    
fermentation 7,schtzenberger and        
,pasteur71 #bec1 #bed     amount        
absorbable by yeast1 #bee     deficiency
 of1 function in fermentation1 #bei     
influence on products1 #ajj1 #ajh1 #aac 
influence on morphology of moulds and   
ferments1 #aje1 #ajf1 #acc1 #acg1       
#bfb     necessity of1 to growth of     
yeast discussed1 #bhj     unnecessary   
and adverse to vibrionic life1 #bhd1 and
 following pages     necessary to       

bacterial life1 #cje     removal from   
solutions by bacteria1 #bie     growth  
of vibrios apart from1 #cjb             
compressed1 influence on ferment life1  
#cbd     determination of1 in worts     
7,schtzenberger71 #cee1 and following   
pages     solubility-coefficients in    
water 7,bunsen71 #cfj     usual amounts 
in solution in brewers' worts1 #cff1    
#cfg       changes in amounts during    
brewing processes1 #cfi1 #cgj           
combination of1 with hopped wort1 #cga1 
and following pages     experiments on  
rapidity of combination1 #cgf       on  
amount of1 under brewing conditions1    
#cgi     in combination with wort not   
available for yeast1 #chj1 #cha         
clarification of wort by1 #che       ,p 
,palate-fulness definition1 #ced1 and   
footnote     impaired by oxidation1 #ced
     ,parasites and their germs1 #dj    
influence on animal diseases1 #da       
,pasteur's repetition of ,trcul's       
experiments1 #ih1 #ii     subject of his
 inquiries stated1 #caa     experiments1

 exactness of1 #ie 7footnote7           
,pasteurization1 meaning and use1 #ae   
7footnote7     ,patches of froth in     
growth of pure yeast1 #ca               
,penicillium glaucum on must1 #ff       
growth of pure1 #hf1 and following pages
     precaution1 #hi     transformed    
into ferment 7,trcul71 #id     spores1  
varieties of1 #ig     production of     
alcohol by1 #ii1 and following pages    
transformation into mycoderma1 #aji     
,phenol for purifying yeasts1 #bcb      
,pitching1 mode of1 for pure beer1 #cdb1
 and following pages     flasks1 #cdd   
peculiar in ,london breweries1          
explanation1 #cej1 #cea     ,plaster of 
,paris and yeast powder1 #ha1 and       
following pages     ,ploussard grapes1  
experiments on1 #afa     ,polymorphism  
of organisms1 #hd 7footnote71 also v4   
transformation     ,precautions for pure
 fermentation of must1 #fd     brewers'1
 to check disease-germs1 #bbj1 and      
following pages     for pure anarobian  
growth of yeast1 #bdh     ,preservation 

of yeast1 #bjg     ,preoccupation of    
liquids by organisms1 #cf1 #aji1 #bbj   
,products of fermentation variable1     
#bgf1 #bgg     ,price of beer as        
affected by losses from disease1 #bd    
,proliferous pellicles1 #aba            
,proportions of alcoholic products      
variable1 #bgf1 #bgg     ,proportions of
 products diagnostic of the             
fermentation1 #bgi     ,proteic matter  
elaborated by cells1 #cce     8,pulling 
up10 #cdc     ,pure growth of yeast1    
precautions for1 #bi-cb     growths in  
natural liquids1 #dj1 #da     wort and  
ferment1 advantages of1 #cia-cic        
,purification of mixed ferments1 #bbf1  
and following pages     practical       
methods1 growth in sweetened water1 #bcj
     shallow basins1 #bca     in acid   
and alcoholic liquids1 #bca     with aid
 of carbolic acid1 #bcb     ,putrid     
wort1 ferments of1 #e     ,putrefaction 
prevented by use of sterilizing flask1  
#bg     of yeast1 cause of1 #bba     of 
tartrate of lime1 #bia       ,q         

,qualities of 8high0 and 8low0 beers1   
#ab1 #ac1 #ai1 #aif     ,quality of beer
 dependent on kind of ferment1 #bf1 and 
following pages       ,r     ,racking1  
#bbb     precautions necessary in1 #cea 
,raulin's fluid1 #hh 7footnote7         
improvement on ,schtzenberger's oxygen  
process1 #cef1 and following            
pages     experiments on solubility of  
oxygen in worts1 #cfa-cfc     ,rayer on 
splenic fever1 c41 #db     ,reducing    
action of vibrios1 #bia     ,rees1 ,dr41
 #aej 7footnote7     ,refrigerator1     
,baudelot's1 #chg 7footnote7            
,revival of mould-cells by aeration1    
#acj1 #aca 7footnote71 #ach     ,revival
 of starved yeast1 #adh1 #bjh           
vibrios1 #cja1 #cjb     ,ripening of    
fruits1 #bgj1 #bga     ,robin1 ,ch41    
mentioned1 #ic2     strictures on       
,pasteur1 #caj1 #caa     recantation of 
views on fermentation1 #cad       ,s    
,saccharomyces apiculatus1 #ga1 and     
footnote1 #aej     exiguus1 #ahe1       
ellipsoideus1 #afe     pastorianus #aea2

       mode of growth of1 #afg     two  
aspects1 globular and filamentous1 #afh1
 #afi     exhaustion and revival of1    
aspects1 #agb1 and following pages      
occurrence as impurity in most ferments1
 #bbe     most suitable for growth      
experiments in sugar solutions1 #ccb    
,saccharomyces pastorianus1             
ellipsoideus1 apiculatus in must1 #bbg1 
and following pages     ,sang de rate1  
#dc     ,schtzenberger on budding of    
yeast1 #adf1 and footnote               
,schtzenberger's strictures on          
,pasteur's views answered1 #beb1 and    
following pages     process for         
determining oxygen in solutions1 #cee   
,seasons1 influence on success in       
brewing1 #be     at which germs are     
absent on fruits1 #eh1 #ei              
,secondary fermentation in ,english     
beers1 #bbd     ,senescence of yeast    
cells1 #bjh     gradual of yeast cells1 
experiments on1 #bde     ,shallow basins
 for purification of yeasts1 #bca       
,sodium hydrosulphite1 v4 hydrosulphite 

,solubility-coefficients of oxygen in   
water 7,bunsen71 #cfj     in worts      
7,raulin71 #cfa-cfc     ,sour beer1     
ferments of1 #e     ,soundness of beer  
always dependent on purity of yeast1    
#bf1 #cb     ,specialization of         
ferment-variations1 #aig     ,specimens1
 necessary precautions for taking1 #abf 
7footnote7     ,splenic fever1 #db      
,spontaneous fermentation used in must1 
not in beer1 #d     fermentation or     
putrefaction prevented by use of        
sterilizing flask1        #bh           
ferment1 definition of1 #ahb2           
experiment on1 #ahd     generation1     
facts against1 #ea1 #eb1 #eg            
supported by experimental errors1 #fb1  
#fc       7,trcul's theory of71 #id1 #ie
     impregnations1 #fe1 #ff1 #fi1 #gc1 
#gi       use in isolating ferments1 #gg
     ,spores on grapes1 gooseberries1   
c41 #ed     of fungi widely distributed1
 #fh     ,statistics of breweries1 #aj  
of ,french beer consumption1 #ag        
7footnote7     ,starved yeast1          

appearance of1 #adh     ,stability of   
sterilized liquids1 #bhf                
,stemphylium spores1 #ee 7footnote7     
,sterilizing apparatus1 #bg1 #bi1 #bhe  
flask1 #bh                              
,sterilization-temperature of various   
liquids1 #cd     ,stock beer1 #bbc      
,store beer1 must be surrounded by ice1 
#af     ,straw wine1 peculiar           
fermentation of1 #aff     ,strength1    
,pasteur's use of word1 #ced     saving 
by the new process1 #cid     ,submerged 
penicillium1 #ii     aspergillus1 #aja1 
and following pages     mycoderma1 #aaa1
 #aac1 and following pages     mucor1   
#abi1 and following pages1 #acc         
,submerging growths1 precautions for1   
#ia 7footnote7     ,succession of       
transformations 7,trcul's scheme71 #ic1 
#id     ,sugar decomposition by         
submerged cells1 #aad     different     
modes of1 by different cells1 #aae      
decomposed disproportionate to yeast    
formed1 #bcg1 and following pages       
variation of disproportion in different 

cases1 #bdi     amount decomposed in a  
given time1 as an index of fermentative 
energy        7,schtzenberger's views71 
#beb     solutions pure with mineral    
salts1 growth of yeast in1 #cag1 and    
following pages     denial of the fact  
by ,liebig and reply by ,pasteur1 #cbh1 
#cbi     ,surface growth of yeast in    
pure culture1 #ca     ,sweetened water  
for exhausting yeast1 #afi1 #agj1 #aij  
for purification of yeasts1 #bcj        
,t       ,tartrate-acid of potash for   
purifying yeasts1 #bca     -dextro of   
lime1 fermentation of1 #bhd1 and        
following pages     products of1 #bhh   
ferment of1 #bij     ,temperatures in   
use in ,london breweries1 #h 7footnote7 
high1 prejudicial to quality of 8low0   
beer1 #ai     at which disease-ferments 
perish1 #bj2       differs in different 
liquids1 #cd1 #if     influence on      
fermentation1 #abi     ,temperatures    
suitable for 8high0 or 8low0 yeasts     
respectively1 #aib     influence of on  
mixed 8high0 and 8caseous0 yeasts1 #bjc 

for observing active vibrios1 #bii      
,theories of generation opposite stated1
 #cig     ,tieghem1 ,van1 on ammoniacal 
urine1 #de       ,torula1 sense in which
 used1 #gc 7footnote7     varieties of1 
#gg     non-fermentative species1 #gh   
,transformation of ferments1 according  
to ,duval1 #cg     of non-fermentative  
to fermentative impracticable1 #hj      
of penicillium into yeast impracticable1
 #ia     of ferment into moulds         
7,hoffmann71 #ib     series1 ,trcul's   
scheme of1 #ic1 #id     of penicillium  
to mycoderma 7,ch4 ,robin71 #aji        
7footnote7     of mycoderma vini        
refuted1 #aac 7footnote7     ,turpin's  
system of1 #abb1 and following pages    
of mycoderma aceti 7,bchamp71 #abd      
historical account of views on1 #abh    
7footnote7     of mucor 7,bail71 #abg   
of filamentous into globular yeast1 #afi
     of yeast into penicillium1 c41     
impracticable1 #ccc-cce     mutual of   
low and high yeast1 discussed1 #aib1    
#aic     of 8high0 yeast into 8caseous0 

ferment illusory1 #bjc     of albumen1  
theory of the vintage1 #bgb1 #bgc       
theory disproved generally1 #bgc        
7footnote7     ,traube1 ,dr41 on        
ammoniacal urine1 #df     researches on 
fermentation1 #bhb     theory of        
fermentation1 #bhc 7footnote7     ,trcul
 and ,fremy1 v4 ,fremy     ,trcul's     
theory of successive transformations1   
#ic1 #id     details of transformation  
experiments1 #ih     theory refuted1 #ii
     ,trousseau grapes1 experiments on1 
#afb     8,turned0 beer1 ferments of1   
#e2     filaments of1 #bc     8,turning 
out10 #cfg 7footnote7     ,turpin1 ,m41 
mentioned1 #ib     ,turpin's system of  
transformations1 #abb1 and following    
pages1 #aac      7footnote7             
,tyndall1 letter to ,pasteur1 #cii-dja  
,u     ,unsoundness of beer correlated  
with disease-organisms1 #bf1 #cb        
,urea-ferment1 the transformation of    
7,duval71 #cg     ,urine1 ammoniacal1   
#de1 #df     ,urine1 sterilized1 study  
of1 #di1 #ej       ,v     ,variability  

of fermentation products1 #bgg          
,variations of ferment strengthened and 
established1 #aig     ,varieties of     
yeast1 #adi1 and following pages        
,vaureal1 ,de1 budding of yeast1 #adf   
7footnote7     ,vegetable distinguished 
from animal organisms by ammonia        
7,robin71 #cab     ,vesicular tissue    
7,turpin71 #abc     ,vibrio1 #cf2       
butyric1 #fe1 #gj     also an example of
 anerobian life1 #bhb1 #bhd     active  
and exhausted1 #bij     reducing action 
of1 #bia     ,vibrionic ferment of      
tartrate of lime1 #bij     ,vibrios1    
head of1 #bib2     supposed reproductive
 corpuscles1 #cjf     growth of1 in     
lactate media1 #bic     medium for      
growth of1 according to ,cohn1 #bid     
7footnote7     not genetically related  
to bacteria1 #bif     of butyric        
fermentation1 description of1 #bih1 #cjj
     mode of examining microscopically1 
#bih     fissiparous division of1 #bii  
measurements of1 #cjj     cannot live on
 butyrates1 #cja 7footnote7     revival 

of1 #cja1 #cjb2     anarobian growth of1
 #cjb     life of1 destroyed by oxygen1 
#cjc1 #cjd     ,vigour of ordinary      
brewer's yeast1 #bdf     ,vin de paille1
 #aff     ,vinegar1 temperature at which
 it is sterilized1 #cd     ,vinous      
flavour in stock beer1 #bbd             
,vintage1 varied conditions of1 #bfh    
7footnote7     fermentation1 theory of1 
according to ,fremy1 #bgb1 and following
 pages     ,viscous wort1 ferments of1  
#e     ,visit to ,london brewery by     
,pasteur1 #bb-bd     ,vital processes of
 ferment exceptional1 #bcg     activity 
of yeast apart from air1 #bei           
potential in cells1 #bgh     ,vitiation 
of experiments1 causes of1 #fc1 #he1 #ib
       ,w     ,wad-dressing1 antiseptic1
 #dd     ,water1 hard1 influence on     
aspect of yeast1 #aid 7footnote7        
,weights of mucor and alcohol1          
proportion of1 #acd1 and following pages
     ,weight of yeast grown1 what due   
to1 #beg 7footnote7     ,wide dishes1   
experiments on fermentation in1 #fi1 #gj

     favourable to mould developments1  
#ge 7footnote7     ,wine1 less liable to
 deteriorate than beer1 #b              
temperature of sterilization1 #cd       
,wort1 definition1 #b2     cooling of1  
#c1 #d     temperature of sterilization1
 #cd     solubility of oxygen in1 #cfa1 
and following pages     formula for     
solubility in any wort1 #cfd     ,worts1
 brewers'1 usual amounts of oxygen in   
solution1 #cff1 #cfg     experiments on 
amounts1 #cgi     ,wort1 hopped1 its    
affinity for oxygen1 #cga1 and following
 pages     mode of transmitting it free 
of oxygen1 #cga1 #cgb     insoluble     
substances in1 #chf       ,y     ,yeast1
 v4 also ferment1 germs1 torul nature   
and properties of1 #adc1      and       
following pages     starved and         
well-nourished1 appearances contrasted1 
#adg1 #adh     varieties of1 #adi1 and  
following pages     commercial origin   
of1 where8 #ahg     relations to other  
organisms1 #ahj1 #aha     commercial    
mixtures1 #bbd1 #bbe     practical      

purification of1 #bcj-bcc     impurities
 in masked for a time1 #bbj             
exceptional characteristics of1 #bcg    
growth of in sterilizing flasks1 #bi-cb 
not transformable into any other        
organism1 #cg     aspect may change     
under modified circumstances1 #cg       
non-transformation of mycoderma vini    
into1 #abj     mucor into1 #acb         
non-fermentative species of1 #gi1 #hj1  
#bjf1 #bjg     8high10 characteristic   
aspect of1 #ahh-aib     well aerated1   
fungoid mode of growth1 #bea            
anarobian growth1 cause of fermentation1
 #bei     growth of1 in solutions of    
sugar1 #cah1 and following pages        
growth in relation to proportion of     
sugar used1 #bcg1 and following         
pages     difficult propagation in      
saccharine mineral media1 #cbi1 #ccj    
growth of1 without producing alcohol1   
#bfe     capacity of absorbing oxygen1  
#bee     necessity of oxygen for its    
growth discussed1 #bhj     incapable of 
using oxygen in combination in worts1   

#chj1 #cha     soluble nitrogenous part 
of1 #cbj1 #cba1 #gi 7footnote7     dried
 into dust still active1 #ha1 and       
following pages     does not perish at  
temperatures at which disease-ferments  
do1 #bj     sudden inactivity of1 cause 
and cure1 #cdg 7footnote7     change of1
 a trade custom1 #bb     reason of      
addition of yeast to wort1 #c           
proportion commonly added1 #c     reason
 of the large proportion used1 #cdc4    
,yeast-cells abundant in brewing        
laboratories1 #ge     gradual senescence
 of1 #bde     ,yeast-cells1 mode of     
examining fruits for1 #bfg 7footnote7   
necessary relation to 8alcoholic        
fermentation10 #bge     ,yeast-water1   
definition1 #gi 7footnote7              
exhaustion of yeast by1 #aga     use of 
in pure growths 7penicillium71 #hh      
8,youth0 of cells1 #bdf      ,pardon    
,sons1 ,printers1 ,paternoster ,row1    
,london4          ,,with ,,numerous     
,,illustrations4    ,,wine3    ,a       
,,treatise ,,on ,,its ,,origin1         

,,nature1 ,,and ,,varieties4    ,,being 
,a    ,,complete ,,manual ,,of          
,,viticulture ,,and ,,nology4    ,,by   
,j4 ,l4 ,w4 ,,thudichum1 ,m4,d41        
,,and    ,,august ,,dupr1 ,,ph4,d4      
,medium #hvo4 #bes4      8,a treatise   
almost unique for its usefulness to     
either the grower1 the  vendor1 or the  
consumer of wine4 ,the analyses given   
are the most  complete we have yet seen1
 exhibiting at a glance the constituent 
principles of nearly all the wines known
 in this country40--,wine ,trade        
,review4    8,we have little doubt that 
this volume will be regarded as the     
standard  ,english work on the subject  
by those whose business is connected    
with  wine40--,chemist and ,druggist4   
8,a perfect magazine of information1    
procured from first sources1 and        
intelligently digested4444 ,this        
exhaustive treatise deserves a cordial  
welcome alike from the wine grower1 the 
wine merchant1 and the consumer1  all of
 whom cannot fail to consult it with    

advantage40--,british ,trade  ,journal4 
,,on ,,the    ,,uses ,,of ,,wine ,,in   
,,health ,,and ,,disease4    ,,by    ,f4
 ,e4 ,,anstie1 ,m4,d41 ,f4,r4,c4,p4     
,crown #hvo4 #bs4      ,,macmillan      
,,co41 ,,london4                        
,,macmillan  ,,co4',s ,,publications4   
,,by ,h4 ,,charlton ,,bastian1 ,m4,d41  
,f4,r4,s4    ,,the ,,beginnings ,,of    
,,life3 ,being some ,account of the     
,nature1 ,modes of  ,origin1 and        
,transformations of ,lower ,organisms4  
,in ,two ,volumes4 ,with  upwards of    
#ajj ,illustrations4 ,crown #hvo4 #bhs4 
,,evolution ,,and ,,the ,,origin ,,of   
,,life4 ,crown #hvo4 #fs4 #f;d4      ,a 
,,treatise ,,on ,,chemistry4 ,by        
,professors ,,roscoe and ,,schorlemmer4 
,vol4 ,i41 ,the ,non-metallic ,elements4
 ,with numerous ,illustrations1 and     
,portrait of ,dalton4 ,medium #hvo4     
#bas4    ,vol4 ,,ii41 ,metals4 ,part ,i4
 ,with ,illustrations4 #hvo4 #ahs4      
7,part ,,ii4 in  the ,press47           
,,lessons ,,in ,,elementary ,,chemistry1

 ,,inorganic ,,and ,,organic4 ,by       
,,professor ,h4  ,e4 ,,roscoe1 ,f4,r4,s4
 ,with numerous ,illustrations1 and     
,chromo-litho of the  ,solar ,spectrum1 
and of the ,alkalis and ,alkaline       
,earths4 ,new ,edition4  ,fcap4 #hvo4   
#ds4 #f;d4    ,a ,,manual ,,of ,,the    
,,chemistry ,,of ,,the ,,carbon         
,,compounds1 ,,or ,,organic ,,chemistry4
  ,by ,c4 ,,schorlemmer1 ,f4,r4,s41     
,lecturer in ,organic ,chemistry in     
,owens  ,college1 ,manchester4 #hvo4    
#ads4    ,a ,,system ,,of ,,volumetric  
,,analysis4 ,by ,dr4 ,e4 ,,fleischer4   
,translated from  the ,second ,german   
,edition by ,m4 ,m4 ,pattison ,muir1    
with ,notes and  ,additions4            
,illustrated4 ,crown #hvo4 #gs4 #f;d4   
,,practical ,,chemistry ,,for ,,medical 
,,students4 ,by ,m4 ,m4 ,,pattison      
,,muir1  ,f4,r4,s4,e4 ,fcap4 #hvo4 #as4 
#f;d4    ,a ,,course ,,of ,,practical   
,,instruction ,,in ,,elementary         
,,biology4 ,by ,t4 ,h4  ,,huxley1       
,,ll4,d41 ,sec4 ,r4,s41 assisted by ,h4 

,n4 ,,martin1 ,b4,a41 ,m4,b41 ,d4,sc41  
,fellow of ,christ's ,college1          
,cambridge4 ,crown #hvo4 #fs4           
,,macmillan  ,,co41 ,,london4           
,transcriber's ,notes3       ,missing or
 obscured punctuation was silently      
corrected4       ,inconsistent spelling 
and hyphenation were made consistent    
only        when a predominant form was 
found in this book4       ,text that was
 in italics is enclosed by underscores  
7italics74       ,text that was in bold 
face is enclosed by equals signs 7bold74
       ,footnotes have been moved to    
follow the chapters in which they are   
referenced4       ,subscripts are       
transcribed by an underscore and a value
 enclosed        in braces1 such as     
,o#b4 ,superscripts are transcribed by  
an        up-caret and a value enclosed 
in braces1 such as ,,mc#b1 or           
sometimes by an up-caret and a single   
character1 such as #d;e4