,transcriber's ,note3 ,italic text is   
indicated by underscores2 boldface  text
 is indicated by equals signs4 ,there is
 an actual equals sign in  the list on  
page #aca4              ,a ,,history    
,,of ,,the ,,sciences          ,,history
      ,,of      ,,chemistry             
,,by      ,,sir ,,edward ,,thorpe1      
,c4,b41 ,,ll4,d41 ,f4,r4,s4             
,,author ,,of 8,,essays ,,in            
,,historical ,,chemistry10 8,,humphry   
,,davy3      ,,poet ,,and               
,,philosopher10 8,,joseph ,,priestley10 
,,etc41 ,,etc4          ,,two ,,volumes 
,i4        ,from the ,earliest ,times to
 the ,middle of the      ,nineteenth    
,century          ,,with ,,illustrations
          ,g4 ,p4 ,,putnam',s ,,sons    
,,new ,,york ,,and ,,london      ,the   
,knickerbocker ,press      #aiji        
,,copyright1 #aiji1 ,,by      ,g4 ,p4   
,,putnam',s ,,sons          ,this series
 is published in ,london by      ,,the  
,,rationalist ,,press ,,association1    
,,limited          ,,publishers' ,,note 

,a ,,history ,,of ,,the ,,sciences has  
been planned to present for the         
information of the general public a     
historic record of the great  divisions 
of science4 ,each volume is the work of 
a writer who is  accepted as an         
authority on his own subject-matter4    
,the books are  not to be considered as 
primers1 but present thoroughly digested
  information on the relations borne by 
each great division of science  to the  
changes in human ideas and to the       
intellectual development  of mankind4   
,the monographs explain how the         
principal scientific  discoveries have  
been arrived at and the names of the    
workers to whom  such discoveries are   
due4    ,the books will comprise each   
about #bjj pages4 ,each volume will     
contain  from #ab to #af illustrations1 
including portraits of the discoverers  
and  explanatory views and diagrams4    
,each volume contains also a concise but
  comprehensive bibliography of the     
subject-matter4 ,the following volumes  

will be issued during the course of the 
autumn of #aiji4        ,the ,history of
 ,astronomy4        ,by ,,george        
,,forbes1 ,m4,a41 ,f4,r4,s41 ,m4 ,inst4 
,c4,e42 author of ,the        ,transit  
of ,venus1 etc4      ,the ,history of   
,chemistry3 ,vol4 ,i4 circa #bjjj ,b4,c4
 to #ahej ,a4,d4      ,vol4 ,,ii4 #ahej 
,a4,d4 to date4        ,by ,,sir        
,,edward ,,thorpe1 ,c4,b41 ,,ll4,d41    
,f4,r4,s41 ,director of the             
,government ,laboratories1 ,london2     
,professor-elect and ,director        of
 the ,chemical ,laboratories of the     
,imperial ,college of ,science          
and ,technology2 author of ,a           
,dictionary of ,applied ,chemistry4     
,to be followed by3      ,the ,history  
of ,geography4        ,by ,dr4 ,,john   
,,scott ,,keltie1 ,f4,r4,g4,s41         
,f4,s4,s41 ,f4,s4,a41 ,hon4 ,mem4       
,geographical ,societies of ,paris1     
,berlin1 ,rome1 ,brussels1              
,amsterdam1 ,geneva1 etc42 author of    
,report on ,geographical                

,education1 ,applied ,geography4        
,the ,history of ,geology4        ,by   
,,horace ,b4 ,,woodward1 ,f4,r4,s41     
,f4,g4,s41 ,assistant-,director of      
,geological ,survey of ,england and     
,wales2 author of ,the ,geology         
of ,england and ,wales1 etc4      ,the  
,history of ,anthropology4        ,by   
,a4 ,c4 ,,haddon1 ,m4,a41 ,sc4,d41      
,f4,r4,s41 ,lecturer in ,ethnology1     
,cambridge and ,london2 author of ,study
 of ,man1 ,magic and        ,fetishism1 
etc4      ,the ,history of ,old         
,testament ,criticism4        ,by       
,,archibald ,,duff1 ,professor of       
,hebrew and ,old ,testament ,theology   
in the ,united ,college1 ,bradford2     
author of ,theology and        ,ethics  
of the ,hebrews1 ,modern ,old ,testament
 ,theology1 etc4      ,the ,history of  
,new ,testament ,criticism4        ,by  
,f4 ,c4 ,,conybeare1 ,m4,a41 late       
,fellow and ,praelector of ,univ4       
,coll41 ,oxford2 ,fellow of the ,british
 ,academy2 ,doctor of        ,theology1 

honoris causa1 of ,giessen2 ,officer d' 
,academie2        author of ,old        
,armenian ,texts of ,revelation1 etc4   
,further volumes are in plan on the     
following subjects3      ,mathematics   
and ,mechanics4      ,molecular         
,physics1 ,heat1 ,life1 and             
,electricity4      ,human ,physiology1  
,embryology1 and ,heredity4             
,acoustics1 ,harmonics1 and the         
,physiology of ,hearing1 together with  
,optics ,chromatics1 and ,physiology of 
,seeing4      ,psychology1 ,analytic1   
,comparative1 and ,experimental4        
,sociology and ,economics4      ,ethics4
      ,comparative ,philology4          
,criticism1 ,historical ,research1 and  
,legends4      ,comparative ,mythology  
and the ,science of ,religions4         
,the ,criticism of ,ecclesiastical      
,institutions4      ,culture1 ,moral and
 ,intellectual1 as ,reflected in        
,imaginative      ,literature and in the
 ,fine ,arts4      ,logic4              
,philosophy4      ,education4           

,,contents        ,,chapter ,i          
,,page      ,,the ,,chemistry ,,of ,,the
 ,,ancients                             
#a        ,egypt1 the alleged birthplace
 of chemistry4 ,origin of the word      
8chemistry40 ,chemical arts known to the
 ancients4 ,metallurgy      of the      
ancients4 ,chemical products of the     
,chinese1 ,egyptians1      ,greeks1 and 
,romans4        ,,chapter ,,ii          
,,the ,,chemical ,,philosophy ,,of ,,the
 ,,ancients                             
#ai        ,ancient speculations as to  
the origin and nature of matter4        
,water the primal principle4 ,thales of 
,miletus4 ,persistency      of his      
doctrine4 ,its influence on science4    
,theories of      ,anaximenes1          
,herakleitos1 and ,pherekides4 ,fire as 
the primal      principle4 ,the         
conception of four primal               
principles--fire1      air1 water1 and  
earth4 ,deification of these by         
,empedocles4      ,plato and ,aristotle4
 ,the doctrine of the four ,elements4   

,influence of the ,peripatetic          
,philosophy on science4 ,arabian        
science4 ,influence of the ,moors in    
,spain4 ,atomic conceptions      of     
,anaxagoras1 ,leukippos1 and            
,demokritos4 ,germs of the atomic       
theory4        ,,chapter ,,iii          
,,alchemy                               
#bh        ,influence of the ,hellenic  
mind on the development of              
chemistry4 ,origin of the idea of the   
transmutation of      metals4           
,philosophical foundation for the belief
 in alchemy4      ,alchemistic theory of
 the nature of metals4 ,origin of the   
conception of the ,philosopher's ,stone4
 ,geber4 ,association of      alchemy   
with astrology4 ,rhazes4 ,avicenna4     
,chemical processes      and substances 
known to the ,arabian chemists4 ,the    
,western      ,alchemists4 ,albertus    
,magnus4 ,roger ,bacon4 ,raymond ,lully4
      ,arnoldus ,villanovanus4 ,johannes
 de ,rupecissa4 ,george ,ripley4        
,basil ,valentine4        ,,chapter ,,iv

      ,,the ,,philosopher',s ,,stone    
#df        ,alchemy in the ,middle      
,ages4 ,association of religion with    
alchemy by the ,christian ,church4      
,alleged nature of the                  
,philosopher's ,stone4 ,its character   
described4 ,its power4      ,the        
,universal ,medicine4 ,the ,elixir of   
,youth4 ,the ,alkahest4      ,opponents 
of alchemy3 ,erastius1 ,conringius1 and 
,kircher4      8,the ,hermes of         
,germany03 ,rudolph ,,ii4 ,christian    
princes who      had dealings with      
alchemists4 ,fate of certain alchemists4
      ,persistency of alchemy and       
hermetic societies4 ,lord ,bacon on     
alchemy4        ,,chapter ,v            
,,iatro-,,chemistry                     
#eg        ,theories of the             
iatro-chemists4 ,paracelsus4 ,doctrine  
of the      tria prima4 ,the            
,paracelsian harmonies4 ,libavius4 ,van 
,helmont4 ,sylvius4 ,willis4 ,services  
of iatro-chemistry      to science4     
,influence of iatro-chemistry on        

technology4      ,agricola4 ,palissy4   
,glauber4 ,chemical products made known 
by      the alchemists4        ,,chapter
 ,,vi      8,,the ,,sceptical           
,,chemist03 ,,the ,,dawn ,,of           
,,scientific ,,chemistry           #gj  
,the foundation of the ,royal ,society  
and other scientific      academies4    
,the appearance of 8,the ,sceptical     
,chemist03 its      attack on the       
doctrines of the ,spagyrists4 ,boyle3   
his life      and character4 ,his       
services to learning4 ,kunkel4 ,becher4 
,mayow4 ,lemery4 ,homberg4 ,boerhaave4  
,stephen ,hales4        ,,chapter ,,vii 
,,phlogistonism                         
#ia        ,becher's hypothesis of the  
,terra ,pinguis4 ,its development       
into the theory of phlogiston4 ,stahl4  
,phlogiston1 primarily      a theory of 
combustion1 becomes a theory of         
chemistry4 ,its      general acceptance 
in ,europe until the last quarter of the
      eighteenth century4 ,prominent    
phlogistians4 ,pott4 ,marggraf4         

,scheele3 his discoveries4 ,duhamel4    
,macquer4 ,black3 his      essay on     
,magnesia ,alba4 ,recognition of the    
individuality      of carbon dioxide4   
,priestley3 his life and character4 ,his
      discoveries in pneumatic          
chemistry4 ,his observations on      the
 influence of vegetable life on the     
character of the      atmosphere4       
,cavendish3 his life and work4          
,discovery of      composition of water4
 ,influence of phlogistonism on the     
development of chemistry4 ,advances made
 during the period of                   
phlogistonism4        ,,chapter ,,viii  
,,lavoisier ,,and ,,la ,r,,volution     
,,chimique                              
#aji        ,downfall of phlogistonism4 
,lavoisier3 his life and work4 ,his     
death4 ,le principe oxygine4 ,principle 
of the conservation      of matter4     
,chemistry a science of quantitative    
relations4      ,prominent              
anti-phlogistians4 ,berthollet4 ,the    
,statique      ,chimique4 ,fourcroy4    

,vauquelin4 ,klaproth4 ,proust4         
,,chapter ,,ix      ,,the ,,atomic      
,,theory                                
#abc        ,the atomic hypotheses of   
the ancients4 ,newton4 ,bergmann4       
,lavoisier4 ,richter4 ,stochiometry4    
,john ,dalton3 sketch of his      life  
and character4 ,how he was led to his   
explanation of the      laws of chemical
 combination4 ,the ,new ,system of      
,chemical      ,philosophy4 ,reception  
of his theory by ,davy and ,wollaston4  
,berzelius3 his life and work4 ,his     
services to chemistry4      ,first      
accurate series of atomic weight        
determinations4      ,avogadro4 ,prout's
 hypothesis4        ,,chapter ,x        
,,the ,,beginnings ,,of                 
,,electro-,,chemistry                   
#adj        ,the ,voltaic ,pile4        
,electrolytic decomposition of water by 
,nicholson and ,carlisle4 ,application  
of voltaic electricity      to the      
decomposition of the alkalis by ,davy4  
,his life and      work4 ,wollaston3 his

 life and work4 ,electro-chemical system
      of ,berzelius4 ,dualism4          
,berzelius reforms chemical notation    
and nomenclature4 ,gay ,lussac3 his life
 and work4 ,thnard3 his      life and   
work4 ,faraday and the law of definite  
electrolytic      action4               
,,chapter ,,xi      ,,the ,,foundations 
,,of ,,organic ,,chemistry              
#aed        ,nicolas ,lemery divides    
chemistry into its two main branches    
of inorganic and organic chemistry4     
,state of knowledge of      products of 
organic origin during the early years of
 the      nineteenth century4 ,animal   
chemistry4 ,doctrine of vital           
force4 ,whler's synthesis of urea4      
,organic chemistry is the      chemistry
 of the carbon compounds4 ,early        
attempts at organic      analysis by    
,lavoisier1 ,berzelius1 ,gay ,lussac1   
and ,thnard4      ,liebig4 ,discovery of
 isomerism and allotropy4 ,cyanogen4    
,theory of compound radicals4 ,etherin  
theory of ,dumas and      ,boullay4     

,memoir of ,liebig and ,whler on oil of 
bitter      almonds4 ,benzoyl theory4   
,investigation of alkarsin by ,bunsen4  
,cacodyl4 ,discovery of zinc ethyl by   
,frankland4        ,,chapter ,,xii      
,,the ,,rise ,,of ,,physical ,,chemistry
                                        
#agj        ,relations of chemistry to  
physics4 ,relations of heat      to     
chemical phenomena4 ,improvements in the
 mercurial      thermometer4 ,newton4   
,shuckburgh4 ,brooke ,taylor4           
,cavendish4      ,black4 ,discovery of  
latent heat by ,black4 ,discovery of    
specific heat4 ,experiments of          
,lavoisier and ,laplace4 ,law      of   
,dulong and ,petit3 its value in        
determining atomic      weights4        
,specific heat of compounds4 ,neumann4  
,discovery of      isomorphism by       
,mitscherlich4 ,foreshadowing of the    
kinetic      theory of gases4 ,discovery
 of the law of gaseous diffusion by     
,graham4 ,liquefaction of gases4 ,monge 
and ,clouet4 ,northmore4      ,faraday4 

,value of a knowledge of weights of unit
 volumes of      gases in determining   
their molecular weights4 ,methods of    
vapour-determination by ,dumas and ,gay 
,lussac4 ,dalton and      ,henry's law  
of gaseous solubility4 ,work of ,schrder
 and ,kopp      on volume relations of  
liquids and solids4 ,connection between 
the chemical nature of a liquid and its 
boiling-point4      ,,bibliography      
#ahc      ,,index                       
#ahg          ,,history ,,of ,,chemistry
          ,,chapter ,i    ,,the         
,,chemistry ,,of ,,the ,,ancients       
,chemistry1 as an art1 was practised    
thousands of years before the           
,christian era2 as a science1 it dates  
no further back than the middle  of the 
seventeenth century4 ,the monumental    
records of ,egypt and the  accounts left
 us by ,herodotus and other writers show
 that the ancient  ,egyptians1 among the
 earliest nations of whom we have any   
records1  had a considerable knowledge  
of processes essentially chemical in    

their nature4 ,their priests were adepts
 in certain chemical arts1 and  chemical
 laboratories were occasionally attached
 to their temples1 as  at ,thebes1      
,memphis1 and ,heliopolis4 ,it is to be 
supposed1 too1 that  in a cultured      
class1 as the priesthood undoubtedly    
was1 there would  be now and again      
curious and ingenious persons who would 
speculate on  the nature and causes of  
the phenomena which they observed4 ,but 
there  is no certain evidence that the  
,egyptians ever pursued chemistry  in   
the spirit of science1 or even in the   
manner in which they and  the ,chaldans 
followed1 for example1 astronomy or     
mathematics4 ,the  operations of        
chemistry as performed by them were of  
the nature of  manufacturing processes1 
empirical in character and utilitarian  
in  result4 ,it was comparatively late  
in the world's history that men were    
found willing to occupy themselves in   
chemical pursuits in order to  gain an  
insight into the nature of chemical     

change1 and to learn the  causes and    
conditions of its action4    ,although  
we have cited the ancient ,egyptians as 
practising the chemical  arts1 there is 
no proof that these arts actually       
originated with them4  ,china1 ,india1  
,chalda have each in turn been regarded 
as the birthplace  of the various       
technical processes from which chemistry
 may be said to  have taken its rise4   
,nevertheless1 it is mainly from        
,egyptian records1  or from writings    
avowedly based on information from      
,egyptian sources1  that such knowledge 
as we possess of the earliest chemical  
processes is  derived4 ,it is           
significant that the word 8chemistry0   
has its origin in  chemi1 8the black    
land10 the ancient name for ,egypt4 ,the
 art itself  was constantly spoken of as
 the 8,egyptian art40    8,the word     
chemistry10 says ,boerhaave in the      
,prolegomena of his ,new  ,method of    
,chemistry 7,shaw and ,chambers's       
translation1 ,london1 #agbg71      in   

,greek should be wrote 1 and in ,latin  
and ,english    chemia and chemistry2   
not as usual1 chymia and chymistry4     
,the first author in whom the word is   
found is ,plutarch1 who    lived under  
the ,emperors ,domitian1 ,nerva1 and    
,trajan4 ,that    philosopher1 in his   
treatise of ,isis and ,osiris1 takes    
occasion    to observe that ,egypt1 in  
the sacred dialect of the country1 was  
called by the same name as the black of 
the eye--viz41 --by    which he seems to
 intimate that the word chemia in the   
,egyptian    language signified black1  
and that the country1 ,egypt1 might take
    its denomination from the blackness 
of the soil4      ,but continues        
,boerhaave the etymology and grammatical
    signification of the name is not so 
easily dispatched4 ,the critics    and  
antiquaries1 among whom it has been a   
great subject of inquiry1    will not   
let it pass without some further        
disquisition4 ,instead of    black1 some
 will have it originally denote secret1 

or occult2    and hence derive it from  
the ,hebrew chaman1 or haman--a         
mystery1 whose radix is cham4 ,and1     
accordingly1 ,plutarch    observes that 
,egypt1 in the same sacred dialect1 is  
sometimes    wrote in ,greek --chamia2  
whence the word is easily deduced       
further from ,cham1 eldest son of ,noah1
 by whom ,egypt was first    peopled    
after the deluge1 and from whom1 in the 
,scripture style1    it is called the   
land of ,cham1 or ,chem4 ,now1 that     
chaman1    or haman1 properly signifies 
secret appears from the same            
,plutarch1 who1 mentioning an ancient   
author named ,menethes    ,sibonita1 who
 had asserted that ,ammon and ,hammon   
were used    to denote the god of       
,egypt1 ,plutarch takes this occasion to
    observe that in the ,egyptian       
language anything secret or occult      
was called by the same name1            
--,hammon4444 ,lastly1 the learned      
,bochart1 keeping to the same sense of  
the word1 chooses to derive    it from  

the ,arabic chema1 or kema--to hide2    
adding that    there is an ,arabic book 
of secrets called by the same name      
,kemi4    ,from the whole of which      
,boerhaave gathers that chemistry was   
thus  originally denominated because it 
was considered of old as 8not fit to  be
 divulged to the populace1 but treasured
 up as a religious secret40    ,if we   
are to credit ,zozimus the ,panopolite1 
who is said to have lived  about the    
beginning of the fifth century1 there   
were sound reasons for  thus treasuring 
up chemistry as a religious secret1     
since1 as it sprang  from the pretium   
amoris1 its origin was not too          
reputable4 8,what the  divine writings  
relate is that the angels1 enflamed with
 the desire  of women1 instructed 'em in
 all the works and mysteries of nature4 
,for which indiscretion they were       
excluded heaven1 as having taught  men  
things unfit for 'em to know40 ,and     
,scaliger asserts that 8,hermes         
testifies as much2 and all our learning1

 both open and occult1 confirms  the    
account40 ,but who ,hermes was1 adds    
that author1 is hard to say1 for  none  
of his writings has survived to our age1
 8that lately published in  ,italy under
 the name of ,hermes ,trismegistus being
 a manifest forgery40    ,this legend of
 the 8feministic0 origin of chemistry is
 in reality much  older than the fifth  
century of our era1 and is but a variant
 of that  which1 according to ,jewish   
writers1 led to the expulsion of man    
from  ,paradise4 ,a similar myth was    
current among the ,phnicians1 ,persians1
  ,greeks1 and ,magi4 ,we trace it in   
the legend of ,sibylla1 who demanded1   
as the price of her favour to ,phbus1   
not only length of years1  but a        
knowledge of the divine arcanum4 ,some  
of the ecclesiastics  who elaborated    
these myths are particular in their     
accounts of the  mysteries thus         
imparted4 ,they included the use of     
charms1 a knowledge  of gold and silver 
and precious stones1 the art of dyeing1 

of painting  the eyebrows1 etc4--the    
kind of arcana1 in fact1 which women in 
all  ages were presumably most keen to  
know4 ,it is1 however1 significant  that
 in all allusions to chemia1 even after 
the translation of  the seat of the     
,roman ,empire to ,constantinople1 it is
 implied that  a knowledge of it was a  
sacred mystery to be known only to the  
priesthood1 and jealously guarded by    
them4 ,it was characteristic of  writers
 who had affixed an eternal stigma on   
,eve to make the sex in  general        
answerable for an illicit knowledge of  
8things unfit for men to  know40        
,for1 in reality1 chemistry originated  
with men1 and it was not so much  in the
 love of women as of wine that it took  
its rise4    ,the manufacture of alcohol
 by processes of fermentation is        
probably  the oldest of the chemical    
arts4 ,the word wine means1 in fact1 a  
product of fermentation4 ,mosaic history
 relates that ,noah1 soon  after he got 
to dry land1 8planted a vineyard and    

drank of the wine10  with results that  
would appear to show that the potency of
 wine  was not unfamiliar to him4       
,diodorus ,siculus1 who studied         
,egyptian  antiquities when ,egypt was a
 ,roman province1 states that the       
ancient  ,egyptians ascribed the origin 
of wine to ,osiris4 ,it was a           
sacrificial  offering even in the       
earliest times1 as was bread4 ,wine     
seems to have  been prepared by the     
,chinese as far back as the time of the 
,emperor  ,y1 circa #bbbj ,b4,c4 ,beer  
was manufactured in ,egypt in the time  
of  ,senwosret ,,iii4 7,sesostris7      
,b4,c4 #ahhj4    ,the ,egyptians were   
skilled in dyeing and in the manufacture
 of  leather1 and in the production and 
working of metals and alloys4 ,they     
were familiar with the methods of       
tempering iron4 ,they made glass1       
artificial gems1 and enamels4 ,the      
oldest known enamel was found as an     
amulet on the ,egyptian ,queen ,aahotep 
7#agjj ,b4,c471 and glass beads were    

made before the time of ,thutmosis      
,,iii4 7#adge ,b4,c474 ,the ,jews knew  
of  gold1 silver1 copper1 iron1 lead1   
and tin4 ,indeed1 it is through them    
and the ,phnicians1 who were among the  
earliest of traders1 that ,europe  was  
gradually made acquainted with many     
technical products of ,eastern  origin4 
,the beginnings of the art of extracting
 and working of metals are  lost in the 
mists of antiquity2 the chemistry of    
metals1 indeed1 has  been said to be    
almost coeval with mankind4 ,diodorus   
,siculus found  traditions in ,egypt as 
to the first inventor of metallurgical  
processes  identical with that of the   
son of ,lamech and ,zillah1 ,tubal-cain1
 or  ,tuval-cain1 of the ,hebrews--the  
,vulcan of the ,romans4    ,gold was    
undoubtedly one of the earliest metals  
to be made use of by  men1 as it        
probably was one of the first to be     
discovered4 ,it occurs  free in nature1 
and is met with in many rocks and in the
 sands of  rivers4 ,its colour1 lustre1 

and density would early attract         
attention  to it2 and its malleability  
and ductility and the ease with which it
  could be fashioned1 together with its 
unalterability1 would render it         
valuable4 ,ethiopian and ,nubian gold   
were known from the earliest times1  and
 quartz crushing and gold washing were  
practised by the ,egyptians4            
,representations of these processes have
 been found on ,egyptian  tombs dating  
from #bejj ,b4,c4 ,gold-wire was used by
 the ,egyptians for  embroidery1 and    
they practised plating1 gilding1 and    
inlaying as far  back as #bjjj ,b4,c4   
,silver also was employed by them1 and  
appears1 like gold1 to have  been coined
 into money4 ,it was originally known as
 8white gold40  ,some of the oldest     
coins in existence are alloys of silver 
and gold1  obtained probably by the     
fusion of naturally occurring           
argentiferous  gold1 such as the pale   
gold of the ,pactolus4 ,such an alloy   
was termed  electrum1 from its          

resemblance in colour to amber4         
,copper is also found to a limited      
extent in the metallic state1 but       
probably the greater part of that used  
by the ancients was obtained  from its  
ores1 which are comparatively abundant  
and readily smelted4  ,it was also used 
for coinage by the ,egyptians1 and was  
fashioned by  them into a variety of    
utensils and implements4 ,the older     
writers drew  no clear distinction      
between copper1 bronze1 and brass1 and  
the terms  designating them--s and --are
 frequently employed2 as by ,pliny1     
indiscriminately4 ,the statement in     
,deut4 viii4 #i--8,out of whose hills   
thou mayest dig brass0--obviously cannot
 mean an alloy of copper and  zinc1     
since this does not occur naturally4    
,pure copper is too soft a metal to be  
used for swords and cutting             
instruments1 but copper ores frequently 
contain associated metals1 as1  for     
example1 tin1 which would confer upon   
the copper the necessary  hardness to   

enable it to be fashioned into weapons4 
,such copper would  be of the character 
of bronze1 and it was known to the early
 workers  that the nature of the metal  
was greatly modified by the selection   
of ores from particular localities4 ,it 
was comparatively late in the           
metallurgical history of copper that    
bronze was produced by knowingly  adding
 tin to the metal4    ,copper was       
largely used by the ,romans1 who        
obtained it from ,cyprus2 it  was known 
to them as s ,cyprium1 and eventually   
,cuprum1 whence we  obtain the chemical 
symbol ,cu4 ,what the ,romans called s  
was found  also at ,chalkis1 in ,euba1  
whence 1 the ,greek word for copper4    
,aurichalcum1 or golden copper--that is1
 brass--was well known to the  early    
workers in copper1 and was made in      
,pliny's time by heating  together      
copper1 cadmia 7calamine71 and charcoal4
    ,bell metal was employed by the     
,assyrians1 and bronze was cast by the  
,egyptians for the manufacture of       

mirrors1 vases1 shields1 etc41 as far   
back as #bjjj ,b4,c4 ,statuary bronze1  
largely used by the ,romans1 usually    
contained more or less lead4    ,tin1   
which was also known to the early       
,egyptians1 would appear to  have been  
first obtained from the ,east ,indies1  
and to have been known  under the       
,sanscrit name of ,kastra 7,ks1 to      
shine71 whence we have  the ,arabic word
 for tin1 ,ksdir1 and the ,greek 1 used 
by  ,homer and ,hesiod4 ,tin ores are   
found in ,britain 7,cornwall71 and were 
brought thence by the ,phnicians4 ,the  
group of islands1 including the  ,scilly
 ,islands and the larger island to the  
east 7,britain71 was known  to the      
,romans as the ,insul ,cassiterides4    
,pliny states that the tin is found in  
grains in alluvial soil1 from  which it 
is obtained by washing2 but he gives no 
description of the  method of smelting4 
,the ,latin word for tin was stannum2 it
 was also  known as plumbum album1 in   
contradistinction to lead1 which was    

called plumbum nigrum4 ,tin was used by 
the ,romans for covering the  inside of 
copper vessels1 and was also            
occasionally employed in the            
construction of mirrors4    ,lead was   
well known to the ,egyptians4 ,in       
,pliny's time it was mainly  procured   
from ,spain and from ,britain           
7,derbyshire74 ,leaden pipes were  used 
by the ,romans for the conveyance of    
water1 and sheet lead was  employed by  
them for roofing purposes4 ,the ,romans 
were also aware of  alloys of lead and  
tin4 ,argentarium was composed of equal 
parts of  lead and tin2 tertiarium1 used
 as a solder1 consisted of two parts of 
lead and one part of tin4    ,iron1     
although now the most important of the  
common metals1 was not  in general use  
until long after the discovery of gold1 
silver1 and  copper4 ,this was probably 
due to the fact that1 although its ores 
are relatively abundant and widely      
distributed1 its extraction as a  metal 
demanded greater skill and more         

appliances than were possessed  by the  
earlier races4 ,metallic iron was1      
however1 well known to the  ,egyptians1 
who employed it in the manufacture of   
swords1 knives1  axes1 and              
stone-chisels1 both as malleable iron   
and as steel4 ,steel  was also known to 
the ,chinese as far back as #bbbj       
,b4,c41 and they were  acquainted with  
the methods of tempering it4 ,the good  
quality of  ,chinese steel caused it to 
be highly prized by ,western nations4   
,the  earliest people to smelt iron are 
supposed to have been the ,chalybes1 a  
nation inhabiting the neighbourhood of  
the ,black ,sea2 it is from them  that  
the ancient name for steel--chalybs--is 
derived1 and also our word              
8chalybeate40    ,mercury has long been 
known1 but there is no evidence that the
  ancient ,egyptians were aware of its  
existence1 or it would probably  have   
been mentioned by ,herodotus4 ,it was   
familiar to ,aristotle1 and  its mode of
 manufacture from cinnabar is described 

by ,theophrastus  7#cbj ,b4,c471 who    
terms it 8liquid silver40 ,processes of 
amalgamation  were known to ,pliny1 who 
notes the readiness with which mercury  
dissolves gold4 ,pliny appears to       
distinguish the native metal found  in  
,spain1 which he terms argentum vivum   
7quicksilver71 from that  obtained by   
sublimation or distillation from        
cinnabar1 which he calls  hydrargyrum1  
from which we get the chemical symbol   
for mercury ,hg4    ,a considerable     
number of metallic compounds were known 
to the ancients1  and were employed by  
them as medicines and as pigments4 ,the 
oxides  of copper1 known as flos ris1   
and scoria ris1 obtained by  heating    
copper bars to redness and exposing them
 to air1 were used as  escharotics4     
,verdigris1 or rugo1 was made by the    
same methods as  now4 ,blue vitriol1 or 
chalcantum1 is described by ,pliny1 who 
says  that the blue transparent crystals
 are formed on strings suspended in  its
 solution4    ,chrysocolla1 malachite1  

or copper carbonate1 was used as a green
  pigment4 ,the blue  of the ,greeks1 or
 cruleum of the ,romans1  was obtained  
by fritting together alkali1 sand1 and  
oxide of copper4  ,botryitis1 placitis1 
onychitis1 ostracitis1 were varieties of
  cadmia or oxide of zinc1 obtained by  
calcining calamine1 and were  used in   
the treatment of ulcers1 etc4           
,molybdena1 which was the ,latin  name  
for litharge1 was employed externally as
 an astringent and in the  manufacture  
of plaster4 ,the lead plaster employed  
by ,roman surgeons was  practically     
identical in character and mode of      
preparation with that  in use to-day4   
,cerussa1 or white lead1 was made as now
 by exposing  sheets of lead to the     
fumes of vinegar4 ,it was used in       
medicine1  as a pigment1 and in the     
preparation of cosmetics4 ,cerussa usta 
was probably red lead4 ,its present name
 of minium was originally  applied to   
cinnabar1 the red sulphide of mercury1  
which was frequently  adulterated with  

red lead4    ,cinnabar1 formerly        
obtained from ,africa1 and1 by the      
,romans1  from ,spain1 was also used    
externally in medicine1 and was a highly
  prized pigment1 whose value was known 
to the ,chinese from very early  times4 
,the black sulphide of antimony1 the    
stimmi and stibium of  ,dioscorides and 
,pliny1 was employed by women in ,asia1 
,greece1 and  latterly in ,western      
,europe1 and is still so used in the    
,east1 for  blackening their eyelashes4 
,preparations of antimony were used in  
medicine4 ,realgar1 the scarlet sulphide
 of arsenic1 the sandarach  of          
,aristotle1 and the arrenichon of       
,theophrastus1 was employed as  a       
pigment1 and also in medicine1 both     
internally and externally4 ,the  yellow 
sulphide of arsenic or auri pigmentum   
7orpiment71 was also  used for the same 
purposes4    ,a variety of yellow and   
red ochres1 in addition to the pigments 
above  mentioned1 were used by painters1
 such as rubrica1 an iron ochre  of a   

dark red colour1 and sinopis1 or reddle1
 obtained from ,egypt1  ,lemnos1 and the
 ,balearic ,isles4 ,oxides of manganese 
were used as brown  pigments4 ,the white
 pigment1 paratonium1 was probably      
meerschaum4  ,melinum was a variety of  
chalk found in ,samos4 ,the ancients    
were well  acquainted with indigo and   
madder1 and with the method of          
manufacturing  lakes1 which was employed
 by ,grecian artists4    ,the famous    
purpurissum was chalk or clay stained by
 immersion in a  solution of ,tyrian    
purple4 ,atramentum was lamp-black3     
ivory-black  was used by ,apelles1 and  
was known as elephantinum4 ,the ink of  
the  ancients consisted of lamp-black   
suspended in a solution of gum or  glue4
 ,the atramentum indicum1 imported from 
the ,east1 was identical  with ,china   
ink4    ,the ancients were well skilled 
in the art of dyeing1 and even of       
calico printing4 ,the ,tyrians produced 
their famous purple dye as far  back as 
#aejj ,b4,c4 ,it was obtained from      

shell-fish1 mainly species of  ,murex1  
inhabiting the ,mediterranean4 ,tyrian  
purple has been shown to  be            
dibrom-indigo1 and to have been produced
 by the action of air and  light upon   
the juices exuded from the shell-fish4  
,the fine linen of the  ,old ,testament 
was probably cotton1 for the production 
of which ,egypt  was long celebrated4   
,that the ,egyptians were acquainted    
with the use of  mordants seems evident 
from the following passage from ,pliny1 
quoted by  ,thomson3--      ,there      
exists in ,egypt a wonderful method of  
dyeing4 ,the white    cloth is stained  
in various places1 not with dye stuffs1 
but with    substances which have the   
property of absorbing colours2 these    
applications are not visible upon the   
cloth1 but when they are    dipped into 
a hot caldron of the dye they are drawn 
out an instant    after dyed4 ,the      
remarkable circumstance is that1 though 
there be    only one dye in the vat1 yet
 different colours appear upon the      

cloth2 nor can the colour be afterwards 
removed4    ,this passage accurately    
describes the process of madder dyeing  
on  cotton1 whereby a variety of fast   
colours--reds1 browns and purples--can  
be obtained from the same vat by the    
employment of different mordants1  such 
as alumina1 oxide of iron1 or oxide of  
tin1 etc4    ,glass has been known from 
very early times4 ,representations of   
glass-blowing were found on the         
monuments of ,thebes and ,beni ,hassan1 
and large quantities of glass were      
exported to ,greece and ,rome from      
,egypt1 mainly by ,phnicians4           
,aristophanes mentions it as hyalos1 and
  speaks of it as the beautiful         
transparent stone used for kindling     
fire4  ,the ,egyptians made use of      
various metallic oxides in colouring    
glass4  ,the hmatinon of ,pliny was a   
red glass coloured with cuprous oxide4  
,cupric oxide was used to colour glass  
green2 and ancient blue glass has  been 
found to contain cobalt4 ,the costly    

vasa murrhina of the ,romans1  obtained 
from ,egypt1 probably consisted of      
fluorspar1 identical with  the ,blue    
,john of the ,derbyshire mines4         
,stoneware has been made from time      
immemorial1 and the ,chinese have       
manufactured porcelain from very remote 
periods4 ,bricks and tiles were  made by
 the ,romans1 and mortar and stucco were
 employed by the ancient  ,egyptians4   
,soap 7sapo7 is mentioned by ,pliny1 but
 its detergent properties were          
apparently unknown to him4 ,it appears  
to have been first made by the  ,gauls1 
who prepared it from the ashes of the   
beech and the fat of  goats1 and used it
 as a pomatum1 as did the jeunesse d'ore
 of ,rome4  ,wood ashes1 as well as     
natron1 were1 however1 used by the      
ancients for  their cleansing           
properties4    ,starch1 acetic acid1    
sulphur1 alumen or crude sulphate of    
alumina1  beeswax1 camphor1 bitumen1    
naphtha1 asphalt1 nitrum 7carbonate of  
soda71 common salt1 and lime1 were all  

known to the ,egyptians1 and were  used 
by them for many of the purposes in     
which they are employed to-day4    ,it  
will be evident from this brief survey  
that the ancients possessed a           
considerable acquaintance with many     
operations of technical chemistry2  but1
 although they must necessarily have    
accumulated a large amount  of          
knowledge1 very little has come down to 
us concerning the mode  in which their  
processes were conducted1 or as to the  
precautions  they employed to ensure    
uniform results4 ,their methods were    
probably  jealously guarded and handed  
down by successive members of the crafts
  as precious secrets4 ,the experienced 
masters of these crafts must  have met  
with many strange and perplexing        
phenomena in the course of  their       
operations1 and a spirit of inquiry must
 thereby at times have  been awakened4  
,but1 under the conditions in which     
their industries  were prosecuted1 the  
scientific spirit was not free to       

develop1 for  science depends           
essentially upon free intercommunication
 of facts and  the spread of knowledge  
of natural phenomena4 ,moreover1 the    
great  intellects of antiquity1 for the 
most part1 had little sympathy with  the
 operations of artisans1 who1 at least  
among the ,greeks and ,romans1  were1   
for the most part1 slaves4 ,philosophers
 taught that industrial  work tended to 
lower the standard of thought4 ,the     
priests1 in most  ages1 have looked more
 or less askance at attempts1 on the    
part of the  laity1 to inquire too      
closely into the causes of natural      
phenomena4 ,the  investigation of nature
 in early times was impossible for      
religious  reasons4 ,there was an outcry
 in ,athens when the thunderbolts of    
,zeus  were ascribed to the collision of
 clouds4 ,anaxagoras1 ,diogenes of      
,apollonia1 ,plato1 ,aristotle1         
,diagoras1 and ,protagoras were charged 
by  the priests with blasphemy and      
driven into exile4 ,prodikos1 who       

deified  the natural forces1 as did     
,empedokles the primal elements1 was    
executed  for impiety4 ,sacerdotalism in
 ,athens had no more sympathy with      
science  than had the ,holy             
,congregation in ,italy when it banned  
the writings of  ,copernicus1 ,kepler1  
and ,galileo1 and sent ,giordano ,bruno 
to the stake4  ,the educated ,greeks had
 no interest in observing or in         
explaining the  phenomena of technical  
processes4 ,however prone they might be 
to  speculation1 they had no inclination
 to experiment or to engage in the      
patient accumulation of the knowledge of
 physical facts4 8,you ,greeks10  says  
,plato in one of his ,dialogues1 8are   
ever children1 having no  knowledge of  
antiquity1 nor antiquity of knowledge60 
,the influence of  a spurious           
,aristotelianism1 which lasted through  
many centuries and  even beyond the time
 of ,boyle1 was wholly opposed to the   
true methods  of science1 and it was    
only when philosophy had shaken itself  

free from  scholasticism that chemistry1
 as a science1 was able to develop4     
,,chapter ,,ii    ,,the ,,chemical      
,,philosophy ,,of ,,the ,,ancients      
,speculations as to the origin and      
nature of matter1 and as to the         
conditions and forces which affect it1  
are to be found1 more or less           
imperfectly developed1 in the oldest    
systems of philosophy of which  we have 
any record4 ,these speculations are not 
based1 in any real  sense1 upon the     
systematic observation of natural       
phenomena4 ,still1  as they appealed to 
human reason1 they must be held to be   
founded  upon experience1 or at least   
not to be consciously inconsistent with 
it3 ,all the oldest cosmogonies regarded
 water as the fundamental  principle of 
things3 from ,okeanos sprang the        
gods--themselves deified                
personifications of the 8elements0 or   
principles of which the world was  made4
    ,in the course of time this doctrine
 of the origin and essential nature  of 

matter came to be more particularly     
associated with the name of  ,thales of 
,miletus1 who lived six centuries before
 our era1 and who1  according to        
,tertullian1 is to be regarded as the   
first of the race  of the natural       
philosophers--that is1 the first of     
those who made it  their business to    
inquire after natural causes and        
phenomena4 ,thales  is known to have    
passed some years of his life in ,egypt1
 and to have  been instructed in science
 by the priests of ,thebes and ,memphis2
 and it  is therefore possible that he  
may have been influenced by the         
,egyptian  teaching in the formulation  
of his cosmological theories4    ,it is 
significant of the tenacity with which  
the mind clings to  dogma and reveres   
authority that the teaching of ,thales  
should have  survived through the space 
of twenty-four centuries4 ,it can be    
shown  to have affected the course of   
chemical inquiry down to the close of   
the eighteenth century4 ,it influenced  

the experimental labours of             
philosophers so diverse in character as 
,van ,helmont1 ,boyle1 ,boerhaave1      
,priestley1 and ,lavoisier--all of whom 
made attempts to prove or disprove  its 
adequacy4 ,van ,helmont1 indeed1 was one
 of the most strenuous  supporters of   
the doctrine of ,thales1 and sought to  
establish it by  observations which1 in 
the absence of all knowledge of the true
 nature  of air and water1 seemed at the
 time irrefutable4 ,perhaps the one most
  frequently cited is his observation on
 the growth of a plant which  apparently
 had no other form of sustenance than   
water4 ,he describes how  he planted a  
willow weighing #e lbs4 in #bjj lbs4 of 
earth previously  dried in an oven4 ,the
 plant was regularly watered1 when at   
the end of  five years it was found to  
weigh #afi lbs4 #c oz41 whereas the     
earth1  after redrying1 had lost only #b
 oz4 in weight4 ,hence1 #afd lbs4 of    
woody matter1 leaves1 roots1 etc41 had  
been produced seemingly from  water     

alone4 ,more than a century had to      
elapse before any clue to the  true     
interpretation of ,van ,helmont's       
experiment was gained4 ,it was  first   
furnished by the observations of        
,ingenhousz and ,priestley4    ,although
 the idea of a primal 8element0 or      
common principle is to be  found in     
every old-world philosophical system1   
the ancient philosophers  were by no    
means in agreement as to its character4 
,anaximenes1 who  lived circa #ejj      
,b4,c41 taught that it was air1         
,herakleitos of ,ephesus  that it was   
fire1 and ,pherekides that it was earth4
 ,the supposition  that a single        
primordial principle could be made to   
account for all  forms of matter and all
 the phenomena and manifestations of the
  material world had its difficulties4  
,attempts to group qualities as         
principles1 and to construct from these 
principles the universe1 were  indeed   
made even prior to the age of ,thales4  
,it was a comparatively  simple         

evolutionary step to regard these       
principles or 8elements0 as  mutually   
convertible4 ,anaximenes' theory of the 
formation of rain was  an implicit      
admission of such convertibility4 ,this 
philosopher taught  that rain came by   
the condensation of clouds1 which in    
their turn  were formed by the          
condensation of air4 ,everything comes  
from air and  everything returns to air4
 ,that water might be converted by fire 
into  air was surmised from the earliest
 times4 ,such a supposition naturally   
sprung from the circumstance that water 
was everywhere recognised to  disappear 
or to pass into the air under the       
influence of fire or solar  heat4 ,the  
supposition had grown into a fixed      
belief in the ,middle ,ages4  ,even     
,priestley1 as late as the end of the   
eighteenth century1 imagined  for a time
 that he had obtained proof of such a   
mutual conversion4  ,the possibility of 
the transmutation of water into earth   
was a belief  current through twenty    

centuries1 and was only definitely and  
finally  disproved by ,lavoisier in     
#aggj4 ,the conception of fire as the   
primal  principle has its germ in the   
fire- or sun-worship of the ,chaldeans1 
,scythians1 ,persians1 ,parsees1 and    
,hindus1 and it is not difficult to     
trace1 therefore1 how heat came to be   
regarded either as antecedent  to1 or as
 associated with1 the other primal      
principles4 ,empedokles1  apparently1   
was the first whose name has come down  
to us to reintroduce  the definite      
conception of four primal               
elements--fire1 air1 water1  and earth4 
,these he regarded as distinct1 and     
incapable of being  transmuted1 but as  
forming all varieties of matter by      
intermixture  in various proportions4   
,these principles he deified1 ,zeus     
being the  personification of the       
element of fire1 ,here of air1 ,nestis  
of water1  and ,aidoneous of earth4     
,the doctrine of the four elements was  
also adopted by ,plato and  amplified by

 ,aristotle1 with whose name indeed it  
is commonly  associated4 ,aristotle1 the
 greatest scientific thinker among the  
,greeks1 exercised an authority almost  
supreme in ,europe during  nearly twenty
 centuries4 ,his influence is to be     
traced throughout  the literature of    
chemistry long after the time of ,boyle4
 ,it may be  detected even now4         
,probably few who write chemical memoirs
 to-day1  and who follow the            
time-honoured practice of prefacing     
their own  contributions to knowledge by
 a statement of what is already known   
on the subject1 are aware that in so    
doing they are obeying the  injunctions 
of ,aristotle4 ,his theory of the nature
 of matter is  contained in his treatise
 on ,generation and ,destruction4 ,it   
mainly  differed from that of           
,empedokles in regarding the four       
8elements0 as  mutually convertible4    
,each 8element0 or principle was        
regarded as being  possessed of two     
qualities1 one of which was shared by   

another element  or principle4    ,thus3
 ,fire is hot and dry2 air is hot and   
wet2 water is cold and wet2  earth is   
cold and dry4    ,in each primal        
8element0 one quality prevails4 ,fire is
 more hot than  dry2 air is more wet    
than hot2 water is more cold than wet2  
earth is  more dry than cold4 ,the      
relative proportion and mutual working  
of  these qualities determined the      
specific character of the 8element40    
,thus1 if the dryness of fire is        
overcome by the moisture of water1  air 
is produced2 if the heat of air is      
overcome by the coldness of  earth1     
water is formed2 if the moisture of     
water is overcome by the  dryness of    
fire1 earth results4 ,ancient chemical  
literature contains  many illustrations 
or diagrams symbolising the             
convertibility or mutual  relations of  
the four 8elements40    ,it has been    
frequently stated that the influence of 
the ,peripatetic  philosophy has been   
inimical to the development of science4 

,but1 in  reality1 the founder of that  
school1 a descendant of ,esculapius1 and
  undoubtedly one of the greatest and   
most enlightened thinkers of  antiquity1
 was an ideal man of science4 ,this is  
abundantly evident  from such of his    
works as can be proved to be genuine4   
,much of what  is called                
,aristotelianism is entirely foreign to 
the spirit of the  teaching of          
,aristotle4 ,the ,aristotelians of the  
,middle ,ages were  mainly              
dialecticians1 and almost wholly        
concerned with the formul of            
syllogistic inference1 and without real 
sympathy with1 or knowledge  of1 his    
system4 ,much1 too1 that was attributed 
to him1 and which was  venerated        
accordingly1 is undoubtedly spurious4   
,the fame of the ,master  has           
consequently suffered at the hands of   
those who1 calling themselves           
,peripatetics1 were in no proper sense  
followers of his method or  interpreters
 of his dogma4 ,aristotle affirmed that 

natural science  can only be founded    
upon a knowledge of facts1 and facts can
 only be  ascertained through           
observation and experiment4 ,he         
illustrates this  particularly by a     
reference to astronomy1 8which10 he     
says1 8is based  on the observation of  
astronomical phenomena1 and it is the   
case with  every branch of science or   
art40 ,it is erroneous and unjust1      
therefore1  to suppose that ,aristotle's
 philosophy1 as he taught it1 is opposed
 to  the true methods of science4    ,a 
knowledge of ,aristotle's works was     
transferred by ,byzantine writers  to   
,egypt2 and1 when that land was overrun 
by the ,arabs in the seventh  century1  
they adopted his system1 spreading it   
abroad wherever their  conquests        
extended4 ,in the eighth century they   
carried it into ,spain1  where it       
flourished throughout their occupation  
of that country4  ,from the ninth to the
 eleventh century the greater part of   
,europe  was in a state of barbarism4   

,the ,moslem caliphate in ,spain1 under 
the beneficent rule of ,jusuf and ,jakb1
 alone preserved science from           
extinction4 ,cordova1 ,seville1         
,grenada1 and ,toledo were the chief    
seats  of learning in ,western ,europe2 
and it was mainly through 8the perfect  
and most glorious physicist10 the       
,moslem ,ibn-,roshd--better known as    
,averroes--7#aabf-aaih71 that ,christian
 scholiasts like ,roger ,bacon  acquired
 their knowledge of the philosophical   
system of ,aristotle1  and mainly       
through the ,moslems ,geber and         
,avicenna that they gained  acquaintance
 with the science of the ,east4    ,the 
conception that matter is made up of    
particles or atoms1 and  that these     
particles are in a state of ceaseless   
motion1 is to be met  with in ,hindu and
 ,phnician philosophy4 ,it was taught by
 ,anaxagoras1  ,leukippos1 and          
,demokritos to the ,greeks1 and by      
,lucretius to the  ,romans4 ,leukippos  
and ,demokritos explained the creation  

of the world as  due solely to physical 
agencies without the intervention of a  
creative  intelligence4 ,according to   
their theories1 the atoms are variable1 
not  only in size1 but in weight4 ,the  
smallest atoms are also the lightest4   
,atoms are impenetrable2 no two atoms   
can simultaneously occupy the same      
place4 ,the collision of the atoms gives
 them an oscillatory movement1  which is
 communicated to adjacent atoms1 and    
these1 in their turn1  transmit it to   
the most distant ones4 ,anaxagoras      
taught that every  atom is a world in   
miniature1 and that the living body is a
 congeries  of atoms derived from the   
aliments which sustain it4 ,plants are  
living  things1 endowed like animals    
with respiratory functions1 and1 like   
them1 atomically constituted4 ,this     
philosopher was so far in advance  of   
his age that his countrymen accused him 
of sacrilege1 and he only  escaped death
 by flight4 ,further1 the assumption    
that these atoms  exert mutual          

attractions and repulsions is probably  
as old as the  fundamental conception   
itself4 ,at least1 so far as can be     
traced1 the  conceptions of atoms and   
atomic motion are indissolubly          
connected4 ,this  is not the place to   
develop the subsequent history of the   
doctrine of  the atom1 nor need we now  
concern ourselves with the old          
metaphysical  quibble of its            
divisibility or indivisibility4 ,it may 
be1 as ,lucretius  said1 that the       
original atom is very far down4 ,it may 
be that the  physical atom is something 
which is not divided1 not something that
  cannot be divided4 ,this theory1 dimly
 perceived in the mists of  antiquity1  
has grown and strengthened with the     
ages1 and in its modern  application to 
the facts of chemistry has acquired a   
precision and  harmony unimagined even  
by the poets and thinkers of old4 ,we   
shall  see later how the whole course of
 the science has been controlled1       
illumined1 and vivified by it4 ,it is   

not too much to say that the  chemistry 
of to-day is one vast elaboration of    
this primeval doctrine4                 
,,chapter ,,iii    ,,alchemy            
,although the intellectual tendencies of
 the ,hellenic mind were hardly         
calculated to favour the development of 
chemistry as a science1 the             
speculations of the ,greeks concerning  
the essential nature of matter  and the 
mutual convertibility of the 8elements0 
led incidentally to an  extension of the
 art of operative chemistry4 ,this      
extension resulted  from attempts to    
realise what was the logical outcome of 
the teaching  of their                  
philosophers--viz41 the possibility of  
the transmutation of  metals4 ,the idea 
of transmutation has its germ in the    
oldest systems  of philosophy4 ,it was a
 plausible doctrine1 not wholly         
unsupported by  the phenomena of the    
organic world2 and it naturally         
commended itself  to men who were only  
too prone to adopt what their cupidity  

and love of  wealth predisposed them to 
believe4    ,it has been assumed that   
alchemy at no time in its history had   
the  slightest claim to a philosophical 
foundation1 but that its professors  and
 adepts1 even at the outset1 consciously
 traded on the credulity and  greed of  
their dupes4 ,much may be urged against 
such a partial view4  ,the supposition  
is not consistent with history or with  
evolutional  tendencies4 ,it may be1 as 
,davy once said1 that 8analogy is the   
fruitful  parent of error20 but the idea
 that metals could be modified--could   
even  be changed one into the           
other--seemed to find support in        
innumerable  chemical phenomena well    
known but imperfectly understood4 ,the  
fact that  alchemy--that is the         
profession of making gold from other    
metals--came to  be practised by rogues 
is no proof that it never had1 and never
 could  have had1 a philosophical basis4
    ,the changes which substances       
experience under the influence of fire1 

air1 and water1 or as the result of     
their action on each other1 are         
frequently so profound that even the    
most superficial of the early  observers
 of chemical processes could not fail to
 be impressed by  them4 ,many of these  
changes are1 in fact1 far more striking 
as regards  alteration in outward       
characters--such as colour1 lustre1     
density1  etc4--than are the differences
 between individual metals2 say1 between
  lead and tin1 or between tin and      
silver1 or between brass and gold4      
,that copper ores1 by appropriate       
treatment with other ores1 or that      
copper itself by the addition of another
 metal1 could be made to  furnish a     
metallic-looking substance having       
certain of the attributes  of gold was  
known to the earliest workers in metals4
 ,what is thought  to be the oldest     
chemical treatise in existence is a     
papyrus in the  possession of the       
,university of ,leyden4 ,it consists of 
a number of  receipts for the working of

 metals and alloys1 and describes       
methods  of imitating and falsifying the
 noble metals4 ,it explains how1 by     
means of arsenic1 a white colour may be 
given to certain metals1 and  how1 by   
the addition of cadmia1 copper acquires 
the colour of gold4  ,the same papyrus  
describes a method of blackening metals 
by the use of  preparations of sulphur4 
,the limited knowledge of chemical      
phenomena  and of chemical processes    
which these early workers necessarily   
possessed1 so far from precluding a     
belief in the possibility of            
transmutation1 actually encouraged it4  
,as nothing was known of the  true      
nature of brass or of its exact relation
 to copper1 it was not  unreasonable to 
suppose that1 if this substance could be
 made to  acquire some of the attributes
 of gold by a process essentially       
chemical1 processes of a like nature    
might cause it to acquire1 if  not all1 
at least so many of them as to enable it
 to pass for gold  of greater or less   

fineness4 ,to them1 as to us1 perfection
 was1 in  technical practice1 a question
 of degree3 the very language of the    
metallurgists of old was in this respect
 nowise different from that of  the     
metallurgists of to-day4    ,it is not  
necessary to suppose that these early   
attempts were  deliberately and         
consciously fraudulent1 like those of   
coiners who  knowingly seek to make an  
alloy of lead and tin simulate silver4  
,the  first alchemists sought in good   
faith to make something which should  be
 of the true nature and essence of gold 
as they conceived it to be4  ,in fact1  
the idea of transmutation had a rational
 foundation in a  theory of the         
intrinsic nature of metals which may be 
looked upon as a  development of the    
ancient beliefs concerning the essential
 nature of  all forms of matter4        
,just as the ,aristotelian 8elements0   
were qualities which1 according to      
their degree1 determined the nature of  
substances1 so1 in like manner1  the    

specific character of a metal depended  
upon the relative proportion  of its    
8sulphur0 and 8mercury40 ,these terms   
had no certain reference  to what we    
to-day understand by sulphur and        
mercury4 ,they denoted  simply          
qualities4 ,the essence or 8element0 of 
mercury conferred lustre1  malleability1
 ductility1 and fusibility1 or1 speaking
 generally1  the properties which we    
connote as metallic2 while to the       
essence  or 8element0 of sulphur was to 
be attributed the combustibility--or1   
speaking generally1 the alterability--of
 the metal by fire4 ,by modifying  the  
relative proportion of these constituent
 elements1 or by purifying  them from   
extraneous substances by the operations 
of chemistry1 it  was conceived that the
 several metals could be changed one    
into the  other4 ,to effect this        
purification it was necessary to add    
various  preparations known as          
8medicines10 chief among which was the  
,great  ,elixir1 or ,magisterium1 or the

 ,philosopher's ,stone1 by which the    
final transformation into the noblest of
 the metals could alone be  achieved4   
,the ,arabic words kmy and iksr were    
originally synonymous and  each was used
 to denote the agent by which the baser 
metals could  be transmuted into silver 
and gold4 ,ultimately the former term   
became restricted to indicate the art of
 transmutation 7alchemy71  whereas iksr1
 or al-iksr1 continued to denote the    
medium by  which the transmutation was  
effected4 ,by later writers the term    
was used to indicate a liquid           
preparation--the quintessence of the    
philosophers--whence we have the word   
elixir1 which always means a  liquid4   
,the alchemistic theory of the compound 
nature and mutual relations of  the     
metals is usually ascribed to ,geber2   
but1 although he adopted it1  he        
distinctly states that it did not       
originate with him1 but that he  found  
it in the writings of his predecessors4 
,the idea of the stone1 the             

philosophical powder1 the grand         
magisterium1 the elixir1 the tincture1  
the quintessence--by  all of which terms
 the transmuting medium is known in the 
literature  of alchemy--is probably     
connected with another conception       
respecting  the origin of metals which  
can be traced to very early times and   
was  prevalent throughout the ,middle   
,ages4 ,it was supposed of old that     
metals were generated within the earth1 
as animals and plants were  generated on
 its surface1 and that something akin to
 a seed1 or semen1  was needed to       
initiate their formation4 ,the great    
problem of alchemy  was to discover this
 fecundating substance1 as upon it      
depended the  genesis of the perfect    
metal4 ,this idea of the conception of  
metals  runs through the literature of  
alchemy4 ,it explains many allusions and
  much of the terminology of its        
writers4 ,for example1 the furnace in   
which the alchemist makes his projection
 is constantly spoken of as the         

philosophical egg4    ,it is impossible 
to say with certainty when and where the
 art of  alchemy originated4 ,there is  
no evidence that it has the antiquity   
which certain of its adepts claimed for 
it4 ,oleus ,borrichius referred  it to  
the time of ,tubal-cain4 ,the earliest  
writers on alchemy were  probably       
,byzantine ecclesiastics1 some of whom  
professed to ascribe  the art to ,egypt1
 and eventually to the mythological     
deity ,hermes1  whose association with  
chemistry in such terms as 8the hermetic
 art10  8hermetically sealed10 etc41 is 
thus explained4    ,this much is        
established--that at some period prior  
to the tenth century  there arose a     
special class of operative chemists1 for
 the most  part more learned in the     
knowledge of chemical phenomena in      
general1  and more skilled in chemical  
manipulation1 than the craftsmen and    
artisans engaged in the manufacture of  
technical products4 ,they devoted       
themselves to searching for methods     

whereby the common and baser metals     
might be converted into silver and gold4
 ,the first known definition  of        
chemistry relates to the aim and        
operations of this special class4  ,it  
occurs in the lexicon of ,suidas1 a     
,greek writer of the eleventh  century1 
who defines chemistry1  as the          
preparation of silver  and gold4        
,attempts at the artificial preparation 
of the noble metals  probably originated
 with the ,arabians1 who followed the   
,egyptians and  the ,greeks in the      
cultivation of chemical pursuits4       
,neither ,hesiod nor ,homer makes       
mention of the art of producing gold    
from any other metal1 or speaks of the  
universal medicine4 ,nor are  they      
referred to by ,aristotle or by his     
pupil ,theophrastus4 ,pliny  nowhere    
speaks of the philosopher's stone1      
although he tells the  story of         
,caligula1 who1 tempted by his avarice1 
sought to make gold  from orpiment      
7auripigmentum7 by distillation4 8,the  

result was that  he did indeed obtain   
both1 and of the finest kind2 but in so 
small  quantity1 and with so much labour
 and apparatus1 that1 the profit not    
countervailing the expense1 he          
desisted40    ,according to ,boerhaave1 
the first author who mentions al-chemia 
is ,julius ,firmicus ,maternus1 who     
lived under ,constantine the ,great1    
and who1 in his ,mathesis1 c4 #ae1      
speaking of the influences of the       
heavenly bodies1 affirms 8that1 if the  
moon be in the house of ,saturn  when a 
child is born1 he shall be skilled in   
alchemy40    ,the first writer who      
mentions the possibility of transmuting 
metals  would appear to be a ,greek     
divine called neas ,garus1 who lived    
towards the close of the fifth century1 
and who wrote a commentary on           
,theophrastus4 ,he was followed by      
,anastatius the ,sinaite1 ,syncellus1   
,stephanus1 ,olimpiodorus2 and1 says    
,boerhaave1 8a crowd of no less  than   
fifty more1 all ,greeks1 and most or all

 of them monks40 8,the art  seemed now  
confined to the ,greeks1 and among them 
few wrote but the  religious1 who from  
their great laziness and solitary way of
 life were  led into vain1              
enthusiastical speculations1 to the     
great disservice and  adulteration of   
the art4444 ,they all wrote in the      
natural style of the  ,schoolmen1 full  
of jargon1 grimace1 and obscurity40     
,experimental alchemy1 as distinguished 
from industrial chemistry1  may1 as     
already stated1 be said to have         
originated with the  ,arabians4 ,at     
first1 alchemy was regarded as a branch 
of the art of  healing1 and its         
professors were invariably physicians   
who occupied  themselves with the       
preparation of chemical medicines4 ,in  
fact1 in  the beginning its true aim was
 regarded as that which ,paracelsus and 
the school of iatro-chemists            
subsequently defined it to be4 ,under   
the rule of the ,caliphs the study of   
chemistry made considerable  progress1  

and its literature was greatly          
augmented4 ,the most notable  name in   
the history of chemistry during the     
eighth century was                      
,abu-,moussah-,dschabir-,al-,sufi--other
wise ,geber--7born #gjb1 died #gfe71    
who is stated to have been either a     
native of ,mesopotamia1 or a ,greek  and
 a ,christian1 who afterwards embraced  
,mahometanism1 went to ,asia1  and      
acquired a knowledge of ,arabic4        
,according to ,leo ,africanus1 a ,greek 
who wrote of the antiquity of the       
,arabs1 ,geber's book was originally    
written in ,greek and translated thence 
into ,arabic1 and he was not  known by  
the name ,geber1 which signifies a great
 man or a prince1  till after this      
version4 ,latin translations of what    
purported to be his  works were first   
published in the early part of the      
sixteenth century1  and an ,english     
rendering appeared in #afgh4 ,according 
to this it would  seem that ,geber      
regarded all the metals as compounds of 

8sulphur0 and  8mercury10 the           
differences between them depending upon 
the relative  proportion and degree of  
purity of these constituents4 ,he is    
said to  have distinguished them by the 
astrological names of the planets3 thus 
gold became ,sol1 silver ,luna1 copper  
,venus1 iron ,mars1 tin  ,jupiter1 and  
lead ,saturn4 ,that an occult connection
 of the metals  with the stars existed  
was part of the creed of alchemy1 and   
the  influence of that belief is still  
traceable in chemical1 and especially   
in pharmaceutical1 literature2 as1 for  
example1 in such terms as ,lunar        
caustic1 ,martian preparations1         
,saturnine solutions1 etc4    ,it has   
been held that the idea of a universal  
medicine had its origin  with ,geber4   
,but this may be due to a misreading of 
his words1 which  in reality may have   
reference to the transmutation of       
metals4 ,he  tells of a medicine which  
cures all lepers4 ,but this may be      
nothing  but allegory4 ,by man is       

probably meant gold1 and by lepers the  
other metals2 and the medicine is the   
universal solvent or agent  which       
transmutes4 ,alchemistic literature is  
full of allegories of  this character4  
,berthelot has shown that in reality    
there were two  ,gebers--one who is     
generally considered to be of ,arab     
origin1 and  another whose identity is  
not established1 but who was probably a 
,western ,european who appears to have  
lived about the year #acjj4a        #a  
,there is very little doubt that the    
work of 8,phileletha10          which   
professed to be taken from an 8,uhralten
 ,,ms40          preserved in the       
,vatican ,library1 entitled ,geberi des 
,kniges der ,araber1 and published by   
,hieron4 ,philipp4          ,nitschel1  
,frankfurth and ,leipzig1 in #agaj1 is  
spurious4    ,other notable names in the
 history of ,arabian alchemy are        
,rhazes1 or  ,ab ,bakr ,mohammed ibn    
,zakary el-,rzi1 who lived circa #ibe1  
and  ,avicenna1 or in ,arabic ,ab ,ali  

el-,hosein ibn-,abdallah ibn-,sina1     
born #ihj1 died #ajcg4 ,the former1 a   
,persian1 practised medicine at         
,baghdad as a follower of ,galen and    
,hippocrates4 ,the latter1 one of  the  
most eminent of ,moslem physicians and a
 voluminous writer1 was a  native of    
,bokhara4 ,he is mainly known in the    
history of science by  his ,canon of    
,medicine1 in which he describes the    
composition and  preparation of         
remedies4 ,he wrote at least one        
treatise on alchemy1 but  others        
attributed to him are probably          
apocryphal4 ,of his ,philosophia        
,orientalis1 mentioned by ,roger ,bacon 
and ,averroes1 no trace remains4        
,although it is reasonably certain that 
the alchemists of the time  of ,geber   
and of his successors had a considerable
 acquaintance with  manipulative        
chemistry1 there were so many impudent  
literary forgeries  during the          
alchemical period that the precise      
extent of the knowledge  possessed by   

the early chemists must always remain   
uncertain4    ,a number of the ordinary 
chemical processes1 such as             
distillation1  sublimation1 calcination1
 filtration1 appear to have been known  
to1  and to have been commonly practised
 by1 the ,arabian chemists2 and many    
saline substances1 such as carbonate of 
soda1 pearlash1 sal-ammoniac1  alum1    
copperas1 borax1 silver nitrate1        
cinnabar1 and corrosive  sublimate1 were
 prepared by them4 ,they seem to have   
known of certain  of the mineral acids1 
and were familiar with the solvent      
properties of  aqua regia4    ,an       
examination of the literature of alchemy
 serves to show how its  principles and 
tenets developed4 ,the philosopher's    
stone is first heard  of in the twelfth 
century4 ,prior to that period the      
greater number of  the ,greek and       
,arabian writers contented themselves   
with affirming the  fact of             
transmutation1 without indicating how it
 might be accomplished4  ,the universal 

medicine and the elixir of life were the
 products of a  later age2 no mention of
 them is known before the thirteenth    
century4    ,alchemy flourished         
vigorously during the ,middle ,ages1 and
 lingered  on even until the early part 
of the nineteenth century4 ,its history 
is simply a long chapter in the history 
of human credulity4 ,for the  most part 
it is a record of self-deception1       
imposture1 and fraud4 ,it  produced an  
abundant literature1 mainly the work of 
ecclesiastics1  between the seventh and 
fourteenth centuries2 but as regards the
  artificial preparation of the noble   
metals or the discovery of the          
universal medicine or the elixir of life
 it was barren of result4    ,although  
no clear line of demarcation is         
possible1 it may be  convenient1 in     
dealing with the personal history of    
alchemy1 to divide  it into the two     
periods before and after ,paracelsus1   
since under his  inspiration and example
 alchemy underwent a great development  

as  regards its professed objects4      
,these eventually became so extravagant 
that1 wide as are the limits of human   
credulity1 its pretensions  gradually   
brought it into disrepute1 and it fell  
by the weight of its  own absurdities4  
,one of the most reputable of the early 
,western alchemists was ,albert  ,groot1
 or ,albertus ,magnus1 born at ,lauingen
 in #aaic4 ,he was a  ,dominican monk1  
who became ,bishop of ,regensburg1 but1 
resigning his  bishopric1 retired to a  
convent at ,cologne1 where he devoted   
himself to  science until his death in  
#abhb4 ,he is credited with having      
written a  number of chemical tracts1   
for the most part in clear and          
intelligible  language1 which is more   
than can be said of the greater portion 
of  alchemistical literature4 ,he gives 
an account of the origin and main       
properties of the chemical substances   
known in his time1 and describes  the   
apparatus and processes used by         
chemists1 such as the water-bath1       

alembics1 aludels1 and cupels4 ,he      
speaks of cream of tartar1 alum and     
caustic alkali1 red lead1 liver of      
sulphur and arsenic1 green vitriol  and 
iron pyrites4    ,contemporaneously with
 him was ,roger ,bacon1 ,doctor         
,mirabilis1  one of the most erudite men
 of his age1 who was born near          
,ilchester  in ,somerset in #abad1 and1 
after studying at ,oxford1 became a     
friar1  occupied himself in             
philosophical pursuits1 and wrote       
numerous tracts  on alchemy4 ,he        
describes what was probably gunpowder1  
but there is  no certain proof that he  
invented it4 ,in his ,de ,secretis      
,artis et  ,natur1 written before #abdi1
 he gives instructions for refining     
saltpetre1 and in an anagram which      
,colonel ,hime1 in his ,gunpowder and   
,ammunition1 has interpreted1 he states 
that a mixture 8which will  produce a   
thundering noise and a bright flash0 may
 be made by taking 8#g  parts of        
saltpetre1 #e of young hazel wood1 and  

#e of sulphur40 ,he died  in #abhe4     
,raymund ,lully1 a friend and scholar of
 ,bacon1 was born in ,majorca  in #abbe 
7others say #abce71 and was buried there
 in #acae4 ,a member of  the ,order of  
,minorites1 he had a great reputation as
 an alchemist2 and  a number of books on
 alchemy and chemical processes are     
ascribed to  him4 ,he described modes of
 obtaining nitric acid and aqua regia1  
and  studied their action upon metals4  
,he obtained alcohol by distillation1   
and knew how to dehydrate it by the aid 
of carbonate of potash1 which  he       
obtained by calcining cream of tartar4  
,he prepared various tinctures  and     
essential oils1 and a number of metallic
 compounds1 such as red  and white      
precipitate4 ,to him is usually ascribed
 the first idea of a  universal         
medicine4    ,there is some difficulty  
in believing that all that is ascribed  
to ,lully was actually the work of his  
age1 for it would appear to  have been a
 common practice with the disciples and 

followers of a  notable scholar to usher
 in their performances under their      
master's  name--a practice not unknown  
in later days4 8,so full are they of    
the experiments and observations which  
occur in our later writers  that either 
the books must be suppositious1 or the  
ancient chemists  must have been        
acquainted with a world of things which 
pass for the  discoveries of modern     
practice0 7,boerhaave74 ,the story is   
that ,lully  plunged into the study of  
chemistry from the desire to cure a     
maiden of  a cancered breast1 and that  
he was stoned to death in ,africa1      
whither  he had journeyed as a          
missionary4 ,it has been further alleged
 that  at one period of his life he made
 gold in the ,tower of ,london by the   
,king's order1 and that he offered      
,edward ,,iii4 a supply of six millions 
to make war against the infidels4 ,as   
,boerhaave drily remarks1 8the  history 
of this eminent adept is very much      
imbroiled40    ,arnoldus ,villanovanus1 

or ,arnaud de ,villeneuve1 a ,frenchman1
 is  said to have been born in #abdj1   
and to have practised medicine in       
,barcelona1 where he incurred the enmity
 of the ,church by reason of his        
heretical opinions1 and was obliged to  
leave ,spain4 ,he led a wandering  life1
 eventually settling in ,sicily1 under  
the protection of ,frederick  ,,ii41 and
 acquired a great reputation as a       
physician4 ,summoned thence by  ,clement
 ,v41 who lay sick at ,avignon1 he lost 
his life by shipwreck in  #acac4        
,johannes de ,rupecissa1 or ,jean de    
,raquetaillade1 a ,franciscan friar  who
 lived from about the middle to the end 
of the fourteenth century1  wrote a     
number of treatises on alchemy1 and     
described methods of making  calomel and
 corrosive sublimate4 ,he was accused of
 the practice of  magic1 and1 by order  
of ,innocent ,,vi41 was thrown into     
prison1 where he  died4 ,he was buried  
at ,villefranche4    ,george ,ripley1 an
 ,englishman1 ,canon of ,bridlington1   

practised alchemy  during the second    
half of the fifteenth century4 ,he spent
 some time  in ,italy in the service of 
,innocent ,,viii4 ,on his return to     
,england he  became a ,carmelite1 and   
died in #adij4 ,like ,bacon1 he was     
charged with  magic4 ,according to      
,mundanus1 he followed alchemy with such
 success  that he was able to advance to
 the knights of ,st4 ,john of ,jerusalem
  large amounts of gold for the defence 
of the ,isle of ,rhodes against the     
,turks4    ,one of the most important   
names in connection with the history of 
alchemy is that of ,basil ,valentine4   
,of his personal history nothing  is    
known4 ,he was supposed to be a         
,benedictine monk who lived in ,saxony  
during the latter half of the fifteenth 
century2 but there are grounds  for the 
belief that the numerous writings       
attributed to him are in  reality the   
work of various hands4 ,the attempt made
 by ,maximilian ,i4 to  discover the    
identity of the author was unavailing1  

nor have subsequent  inquiries had any  
better result4 ,the collection of books 
bearing his  name1 first published in   
the beginning of the seventeenth        
century1  reveals quite a remarkable    
number of chemical facts up to that time
 not  generally known4 ,the most        
important of these relate to antimony   
and its  preparations1 such as butter of
 antimony1 powder of algaroth1 oxide  of
 antimony1 etc4 ,he seems to have known 
of arsenic1 zinc1 bismuth1  and         
manganese4 ,he described a number of    
mercurial preparations1 and  many of the
 salts of lead were known to him4 ,he   
mentions fulminating  gold1 and was     
aware that iron could be coated with    
copper by immersion  in a solution of   
blue vitriol4 ,he knew of green vitriol 
and the  double chloride of iron and    
ammonium1 and gave the modes of making  
a considerable number of other metallic 
salts1 such as the sal  armoniacum1     
which we now know as sal ammoniac4 ,he  
also appears to have  prepared ether and

 the chloride and nitrate of ethyl4     
,there is reason to believe1 as stated  
already1 that many of the  published    
works ascribed to these learned men are 
the work of obscure  individuals who    
traded on their fame4 ,what may with    
certainty be  credited to them serves to
 show that their theoretical opinions   
had  much in common4 ,they all regarded 
the transmutation of metals and  the    
existence of the philosopher's stone as 
facts which could not be  controverted4 
,they followed ,geber in assuming that  
all the metals were  essentially        
compound in their nature1 and consisted 
of the essence or  8element0 of mercury1
 united with different proportions of   
the essence  or 8element0 of sulphur4   
,the alchemists were the professional   
chemists of their time1 and many  of    
them were practising physicians4        
,indeed1 professional chemistry may  be 
said to have originated out of the      
practice of physic4 ,as the number  of  
chemical products increased and their   

value in therapeutics became  more and  
more appreciated1 there arose another   
school of alchemists1  whose energies   
were devoted1 not to the transmutation  
of metals--which1  however plausible as 
a belief1 seemed hopeless of            
achievement--but to  the more immediate 
practical benefits which it was         
recognised must  follow from the closer 
association of chemistry and medicine4  
,this  school came to be known as the   
iatro-chemists4 ,as their doctrines     
exercised a great influence upon the    
development of chemistry1 it  will be   
desirable to treat of them and their    
professors in a special  chapter4       
,,chapter ,,iv    ,,the ,,philosopher',s
 ,,stone      ,during the fourteenth1   
fifteenth1 and sixteenth centuries the  
cult of  alchemy attained to the dignity
 of a religion4 ,belief in transmutation
  and in the virtues and powers of the  
philosopher's stone1 in the  universal  
medicine1 the alkahest1 and the elixir  
of life1 formed its  articles of faith4 

,the position it acquired was due to    
some extent to  the attitude towards it 
of the ,romish ,church4 ,many reputable 
bishops  and fathers were professed     
alchemists2 and chemical laboratories1  
as  in the ,egyptian temples1 were to be
 found in monasteries throughout        
,christendom4 ,pope ,john ,,xxii41 who  
had a laboratory in his palace  at      
,avignon1 is the reputed author of a    
work1 ,ars ,transmutatoria1  published  
in #aeeg4 ,but to a still larger extent 
it was due to the fact  that alchemy    
appealed to some of the strongest of    
human motives--the  wish for health1 the
 fear of death1 and the love of wealth4 
,it was a  cunningly devised system1    
which exploited the foibles and         
frailties of  human nature4 ,the policy 
of the ,church1 however1 it should be   
said1 was  not consistently and         
uniformly favourable to alchemy4 ,its   
practices  occasionally came under the  
papal ban1 although at times1 to suit   
the  exigencies of ,christian princes1  

the interdict was removed4 ,theosophy   
and mysticism were first imported into  
alchemy1 not by ,arabs1 but by          
,christian workers4 ,the intimate       
association of religion with alchemy    
during the ,middle ,ages is obvious in  
the writings of ,lully1 ,albertus       
,magnus1 ,arnaud de ,villeneuve1 ,basil 
,valentine1 and other ecclesiastics4    
,invocations to divine authority are    
freely scattered over their pages4      
,even the lay alchemist professed to    
rule his life and conduct by the        
example and precepts of the good ,bishop
 of ,regensburg4 ,he was directed  to be
 patient1 assiduous1 and persevering2   
discreet and silent2 to work  alone2 to 
shun the favour of princes and nobles1  
and to ask the divine  blessing on each 
operation of trituration1 sublimation1  
fixation1  calcination1 solution1       
distillation1 and coagulation4          
,although alchemy1 at least in its      
decadent days1 lived for the most  part 
by its appeal to some of the lowest     

instincts of mankind1 and is  only worth
 notice as a transient phase in the     
history of science1 a  few details      
concerning the tenets and practices of  
its professors may  be of interest to   
the curious reader4 ,and first as       
regards the nature  of the philosopher's
 stone--the grand magistery1 the        
quintessence4  ,many alchemists         
professed to have seen and handled it4  
,it is usually  described as a red      
powder4 ,lully mentions it under the    
name of  ,carbunculus4 ,paracelsus says 
that it was like a ruby1 transparent    
and brittle as glass2 ,berigard de ,pisa
 that it was of the colour of  a wild   
poppy1 with the smell of heated sea     
salt2 ,van ,helmont that it  was like   
saffron1 with the lustre of glass4      
,helvetius describes it  as of the      
colour of sulphur4 ,lastly1 an unknown  
writer1 under the  pseudonym of         
8,kalid10 says that it may be of any    
colour--white1 red1  yellow1 sky-blue1  
or green4 ,as the substance was wholly  

mythical1 a  certain latitude of        
description may reasonably be expected4 
,some of  the alchemists were of opinion
 that the magistery was of two          
kinds--the  first1 the grand magistery1 
needed for the production of gold2 the  
second1 the small magistery1 only       
capable of ennobling a metal as far  as 
the stage of silver4 ,then1 as to the   
amounts required to effect a            
transmutation1 accounts are equally     
discrepant4 ,arnaud de ,villeneuve  and 
,rupescissa assert that one part of the 
grand magistery will convert  a hundred 
parts of a base metal into gold2 ,roger 
,bacon1 a hundred  thousand parts2      
,isaac of ,holland1 a million4 ,raymond 
,lully states that  philosopher's stone 
is of such power that even the gold     
produced by  means of it will ennoble an
 infinitely large amount of a base      
metal4    ,it is hardly necessary to    
state that a preparation of such potency
  is capable of effecting anything or   
everything2 and accordingly1 as  time   

went on1 other attributes than that of  
transmutation came to be  associated    
with it4 ,it may be1 as ,boerhaave      
surmises1 that the idea of  a universal 
medicine had its origin in a too literal
 interpretation  of ,geber's allegory of
 the six lepers4 ,be this as it may1    
during the  fourteenth and fifteenth    
centuries the philosopher's stone was   
gravely  prescribed as a means of       
preserving health and prolonging life4  
,in  case of illness one grain was      
directed to be dissolved in a sufficient
  quantity of good white wine1 contained
 in a silver vessel1 the draught  to be 
taken after midnight4 ,recovery would   
follow after an interval  depending upon
 the severity and age of the complaint4 
,to keep in good  health1 the dose was  
to be repeated at the beginning of      
spring and  autumn4 8,by this means10   
says ,daniel ,zacharias1 8one may enjoy 
perfect  health until the end of the    
days assigned to one40 ,isaac of        
,holland  and ,basil ,valentine are     

equally explicit1 but in their case it  
is  recommended that the dose should be 
taken once a month3 thus life would  be 
prolonged 8until the supreme hour fixed 
by the king of heaven40  ,other         
alchemists were not always so prudent in
 prophecy4 ,artephius gave  the limit of
 human life thus prolonged as a thousand
 years2 ,gualdo1  a ,rosicrucian1 was   
stated to have lived four hundred years4
 ,raymond  ,lully and ,salomon          
,trismosin1 we are told1 renewed their  
youth by means  of it4 ,the advanced age
 at which ,noah begat children could    
only be  due1 says ,vincent de          
,beauvais1 to his use of the            
philosopher's stone4  ,dickinson wrote a
 learned book to prove that the great   
age of the  patriarchs was owing to the 
same secret4    ,but not only were      
health and length of days the fortunate 
lot of him  who possessed the           
philosopher's stone2 increase of wisdom 
and virtue  equally followed from its   
use4 ,as it ennobled metals1 so it freed

  the heart from evil4 ,it made men as  
wise as ,aristotle or ,avicenna1        
sweetened adversity1 banished           
vain-glory1 ambition1 and vicious       
desires4 ,adam received it at the hands 
of ,god1 and it was given also to       
,solomon1 although the commentators were
 rather exercised to know why1  as he   
possessed the philosopher's stone1 he   
should have sent to ,ophir  for gold4   
,it would serve no good purpose to      
attempt to describe the recipes  given  
by various alchemists to prepare this   
precious substance4 ,with  an           
affectation at times of precision1 they 
were purposely obscure1 and  always     
enigmatical4 ,as ,boyle said of them1   
they could scarcely keep  themselves    
from being confuted except by keeping   
themselves from being  clearly          
understood4 ,one example of their       
recipes must suffice3 8,to fix          
quicksilver4--,of several things take   
#b1 #c and #c1 #a2 #a to #c is #d2 #c1  
#b  and #a4 ,between #d and #c there is 

#a2 #c from #d is #a2 then #a and #a1 #c
 and  #d2 #a from #c is #b4 ,between #b 
and #c there is #a1 between #c and #b   
there is  #a4 #a1 #a1 #a1 and #a1 #b1 #b
 and #a1 #a and #a to #b4 ,then #a is   
#a4 ,i have told  you all40 ,no wonder1 
after an equally luminous explication1 a
 pupil  of ,arnaud de ,villeneuve should
 have exclaimed3 8,but1 master1 ,i do   
not  understand40 ,upon which the master
 rejoined that he would be clearer      
another time4    ,nor is it necessary to
 dilate upon the other virtues which    
were  ascribed at various times to the  
philosophical powder1 as1 for  example1 
its power of making pearls and precious 
stones1 or of its  use in preparing the 
alkahest1 or universal solvent1 invented
 by  ,paracelsus4 ,in their attempts to 
fathom the depths of human credulity    
the alchemists at length over-reached   
themselves4 ,the idea of a  universal   
solvent carried with it1 as ,kunkel     
pointed out1 its own  refutation3 if it 
dissolved everything1 no vessel could   

contain it4 ,and  yet1 says ,boerhaave1 
a whole library could be filled with    
writings by  the school of ,paracelsus  
on the alkahest4 ,from the latter end of
 the  sixteenth century repeated        
attempts were made to expose the        
pretensions  and demonstrate the        
absurdities of alchemy4 ,among its      
adversaries may  be cited ,thomas       
,erastius1 ,hermann ,conringius1 and the
 ,jesuit ,kircher4  ,many of their      
dupes1 potentates and princes who were  
powerful enough  to exercise it1        
occasionally visited with their         
vengeance those who1  unmindful of the  
injunctions of ,albert the ,great1 had  
traded too long  upon their credulity4  
,the ,emperor ,rudolph ,,ii41 who earned
 the title of  8,the ,hermes of         
,germany10 was a zealous cultivator of  
alchemy1 and had a  well-equipped       
laboratory in his palace at ,prague1 to 
which every adept  was welcome4         
,ferdinand ,,iii4 and ,leopold ,i4 were 
also patrons of the  hermetic art1 as   

were ,frederick ,i4 and his successor1  
,frederick ,,ii41  ,kings of ,prussia4  
,indeed1 at one period nearly every     
,court in ,europe  had its alchemist1   
with the privileges of the ,court fool  
or the poet  laureate4 ,the fraud and   
imposture to which the practice gave    
rise led  occasionally to the           
promulgation of stringent laws against  
it1 and at  times the pursuit of        
operative chemistry became well-nigh    
impossible  in some countries4 ,in the  
fifth year of the reign of ,henry ,,iv4 
7#adjd7  it was enacted that 8,none from
 henceforth shall use to multiply gold  
or silver1 or use the craft of          
multiplication2 and if the same do he   
shall incur the pain of felony40        
,according to ,watson1 the true reason  
for passing this ,act was not an        
apprehension that men should ruin their 
fortunes by endeavouring to make gold1  
but a jealousy lest ,government  should 
be above asking aid of the subject4 ,at 
the same time1 letters  patent were     

granted to several persons1 permitting  
them to investigate  the universal      
medicine and perform the transmutation  
of metals4    ,alphonse ,x41 of         
,castille1 the author of the ,key of    
,wisdom1 practised  alchemy4 ,henry     
,,vi41 of ,england1 and ,edward ,,iv4   
had dealings with  adepts4 ,even        
,elizabeth ,tudor1 who was a shrewd     
enough sovereign1  had the notorious    
,dr4 ,dee in her pay4 ,charles ,,vii4   
and ,charles ,,ix41  of ,france1        
,christian ,,iv41 of ,denmark1 and      
,charles ,,xii41 of ,sweden1  sought to 
replenish their exhausted treasuries by 
the aid of the  philosopher's stone4 ,if
 princes eventually learned not to put  
their  trust in alchemists1 alchemists  
learned equally to their cost not to    
put their trust in princes4 ,duke       
,julius1 of ,brunswick1 in #aege1 burnt 
a female alchemist1 ,marie ,ziglerin1   
who had failed in her promise to        
furnish him with a prescription for the 
making of gold4 ,david ,benther  killed 

himself to escape the fury of the       
,elector ,augustus1 of ,saxony4         
,bragadino was hanged at ,munich in     
#aeij by the ,elector of ,bavaria4      
,leonard ,thurneysser1 who gained an    
evil notoriety in his day as one of  the
 most unscrupulous of the followers of  
,paracelsus1 and who amassed            
considerable wealth by the sale of      
cosmetics and nostrums1 was deprived  of
 his ill-gotten gains in #aehd by the   
,elector of ,brandenburg1 and  died in  
misery in the convent4 ,borri1 a        
,milanese adventurer1 who had  deceived 
,frederick ,,iii41 of ,denmark1 was     
imprisoned for years by that  monarch1  
and died in captivity in #afie4 ,william
 de ,krohnemann was  hanged by the      
,margrave of ,byreuth1 who1 with grim   
irony1 caused the  inscription to be    
fixed to his gibbet3 8,i once knew how  
to fix mercury1  and now ,i am myself   
fixed40 ,hector de ,klettenberg was     
beheaded in #agbj  by ,augustus ,,ii41  
,king of ,poland4    ,all the followers 

of ,hermes were not so wary or so candid
 as the  artist who declined an         
invitation to visit the ,court of       
,rudolph ,,ii41  saying3 8,if ,i am an  
adept1 ,i have no need of the ,emperor2 
if ,i am not1  the ,emperor has no need 
of me40 ,well might ,john ,clytemius1   
,abbot of  ,wiezenberg1 write3          
8,vanitas1 fraus1 dolus1 sophisticatio1 
cupiditas1  falsitas1 mendacium1        
stultitia1 paupertas1 desesperatio1     
fuga1  proscriptio et mendicitas1       
perdisque sunt chemi40    ,despite the  
attacks of ,kunkel1 ,boerhaave1 the     
elder ,geoffroy1 ,klaproth1  and other  
chemists of influence and repute1       
alchemy died hard4 ,it  found believers 
in ,england until near the close of the 
eighteenth  century1 and was professed  
even by a ,fellow of the ,royal         
,society--,dr4  ,james ,price1 of       
,guildford1 who1 in chagrin at the      
exposure of his  pretensions1 put an end
 to his existence in #aghc4 ,hermetic   
societies  existed in ,westphalia1 at   

,knigsberg1 and at ,carlsruhe down to   
the  first decade of the nineteenth     
century4 ,m4 ,chevreul1 who lived well  
into that century1 relates that he knew 
of several persons who were  convinced  
of the truth of alchemy1 among them     
8generals1 doctors1  magistrates1 and   
ecclesiastics40 ,the strange medley of  
alchemy1  theosophy1 thaumaturgy1 and   
cabalisticism professed by ,christian   
,rosenkreuz is not without its          
adherents1 even in this twentieth       
century4    ,if the baser metals have   
not been made to furnish gold1 truth at 
least  has followed from the practice of
 error4 ,this is the only transmutation 
which the art of ,hermes has succeeded  
in effecting4 ,to err is human4         
,although alchemy is not without its    
special interest as one of the  most    
remarkable aberrations in the history of
 science1 some of its  practitioners1 it
 must be admitted1 deceived only        
themselves3 if  misguided1 they were at 
least honest1 and pursued their calling 

in a  settled conviction of the         
soundness of their faith4 ,although they
 never  reached their goal--the         
discovery of the ,philosopher's ,stone  
and the  ,elixir of ,life--their labours
 were not wholly vain1 for many new and 
unexpected facts came to light as the   
result of their assiduity4              
8,credulity in arts and opinions10 wrote
 ,lord ,bacon in ,de ,augmentis         
,scientiarum1      is likewise of two   
kinds--viz41 when men give too much     
belief to    arts themselves1 or to     
certain authors in any art4 ,the        
sciences    that sway the imagination   
more than the reason are principally    
three--viz41 astrology1 natural magic1  
and alchemy4444 ,alchemy may    be      
compared to the man who told his sons   
that he had left them    gold1 buried   
somewhere in his vineyard2 while they by
 digging found    no gold1 but by       
turning up the mould about the roots of 
the vines    procured a plentiful       
vintage4 ,so the search and endeavours  

to make    gold have brought many useful
 inventions of light4          ,,chapter
 ,v    ,,iatro-,,chemistry      ,the    
term 8iatro-chemistry0 denotes a        
particular phase in the history  of     
medicine and of chemistry4 ,the         
iatro-chemists were a school of         
physicians who sought to apply chemical 
principles to the elucidation  of vital 
phenomena4 ,according to them1 human    
illnesses result from  abnormal chemical
 processes within the body1 and these   
could only be  counteracted by          
appropriate chemical remedies4 ,although
 this idea did  not originate with him1 
the chief exponent of this school is    
commonly  said to be ,paracelsus4    ,a 
man of violent passions1 coarse1        
drunken1 arrogant1 and unscrupulous1    
,philippus ,aureolus ,theophrastus      
,paracelsus ,bombastus von              
,hohenheim--to  give him his full       
name--would seem to have possessed none 
of the  attributes needed by the        
successful leader of an intellectual    

revolution4    ,born at ,etzel in       
,switzerland in #adic1 son of a         
physician1 ,william  ,bombast von       
,hohenheim1 who combined the practice of
 astrology with  that of alchemy1       
,paracelsus1 even as a youth1 became a  
wanderer1  passing from province to     
province and cloister to cloister1      
living  by telling fortunes and         
practising sometimes as a quack and at  
other  times as an army surgeon1 and    
gaining1 as he tells us1 much curious   
information from old women1 gipsies1    
conjurers1 and chemists4 ,if we may     
trust his own account of himself1 he    
had1 before he was thirty-three1        
wandered over the whole of ,europe1 and 
even into ,africa and ,asia1  everywhere
 performing miraculous cures and        
constantly getting into  trouble4 ,in   
#aebf he secured the appointment of     
,professor of ,physic in  the           
,university of ,basle1 and signalised   
his occupancy of the chair  by a course 
of lectures--a farrago of confused      

,german and barbarous  ,latin--in which 
he assailed with extraordinary vigour   
and unexampled  coarseness the medical  
system of the school of ,galen4         
,scandalised as  his professional       
brethren might be1 ,paracelsus          
expressed1 intentionally  or            
unintentionally1 the feeling of         
impatience with which the laity  viewed 
a system of therapeutics based only on  
tradition4 ,in this revolt  against     
authority he initiated a movement which1
 whatever might have  been its influence
 on medicine1 served eventually1 under  
the guidance  of worthier men1 to       
emancipate chemistry from the thraldom  
of alchemy4    ,paracelsus did little   
more than initiate4 ,although his many  
tracts  show that he was familiar with  
nearly every chemical preparation of    
his time1 many of which he used in his  
practice1 he added no new  substance to 
science4 ,a man of great ability and    
extraordinary talent1  he squandered his
 powers in dissipation4 ,his intemperate

 conduct soon  lost him his chair at    
,basle2 and1 after an ignoble quarrel   
with the  magistracy1 he fled the town1 
and1 resuming his wandering life1 died1 
under wretched circumstances1 at        
,salzburg1 in his forty-eighth year4    
,space will not permit of any account of
 the philosophical opinions  of         
,paracelsus--of his mysticism1 his      
theosophy1 his pantheism1 his           
extraordinary doctrine of the ,archus   
and ,tartarus1 his association of       
astrology with medicine4 ,his chief     
merit lies in his insistence that  the  
true function of chemistry was not to   
make gold artificially1 but  to prepare 
medicines and substances useful to the  
arts4 ,he thereby made  chemistry       
indispensable to medicine1 and          
thenceforward chemistry began  to be    
taught in the universities and in the   
schools as an essential  part of a      
medical education4    ,paracelsus is    
usually regarded as a typical           
alchemist--the kind of  man made        

familiar to us by the paintings of      
,teniers1 ,van ,ostade1 and  ,stein--a  
boorish1 maudlin knave1 who divided his 
time between the  pothouse and the      
kitchen in which he prepared his        
extracts1 simples1  tinctures1 and the  
other nostrums which he palmed off upon 
a credulous  world1 as ignorant and     
superstitious as himself4 ,there is much
 in the  personal history of ,paracelsus
 that serves to justify such a view of  
him4 ,that he was in the main an        
impudent charlatan1 ignorant1 vain1 and 
pretentious1 there can be little doubt4 
,he had an astonishing audacity  and a  
boundless effrontery2 and it was largely
 by the exercise of these  qualities    
that he secured such professional       
success as he enjoyed4    ,to judge from
 the number of the published works      
associated with his  name1 he was an    
active and industrious writer4          
,considering that during  the greater   
part of his waking time he was more or  
less intoxicated1 it  is difficult to   

conceive what opportunity he had for    
composing them4  ,only one or two are   
known to be genuine4 ,these1 according  
to ,operinus1  his publisher1 he        
dictated2 and from their incoherence and
 obscurity1  their mystical jargon1 and 
misuse of terms1 they read like the     
ravings  of one whom drunkenness had    
deprived of reason4 ,many of the tracts 
and  larger works appeared after his    
death--some of them years after2 and    
there is no certain proof that he was   
the actual author4 ,even if we  regard  
them as suppositious1 the fact that they
 should be published  under his name is 
significant of the influence and        
notoriety which this  extraordinary man 
succeeded in achieving during his short 
and chequered  career4    ,the immediate
 followers of ,paracelsus--among whom   
may be named  ,thurneysser1 ,dorn1      
,severinus1 ,duchesne--distinguished    
themselves only  by the boldness with   
which they promulgated his doctrines1   
and the  unscrupulous use which they    

made of his methods4 ,they were all     
zealous  anti-,galenists1 who professed 
to believe that the sum and perfection  
of human knowledge was to be found in   
the ,cabala1 and that the secrets  of   
magical medicine were contained in the  
,apocalypse4 ,they adopted  pantheism in
 all its grossness3 everything that     
exists eats1 drinks1  and voids         
excrement2 even minerals and liquids    
assimilate food1 and  eliminate what    
they do not incorporate4 ,sylphs inhabit
 the air1 nymphs  the water1 pigmies the
 earth1 and salamanders the fire4 ,thus 
even the  ,aristotelian elements were   
animated4 ,mercury1 sulphur1 and salt   
were1  according to ,paracelsus1 the    
primal principles which entered into    
the composition of all things1 material 
and immaterial1 visible and  invisible4 
,the following so-called 8harmonies0    
were essential articles  of faith with a
 ,paracelsian3--        ,soul           
,spirit     ,body      ,mercury         
,sulphur    ,salt      ,water      ,air 

,earth    ,the laws of the ,cabala were 
held to explain the functions of the    
body4  ,the sun rules the heart1 the    
moon the brain1 ,jupiter the liver1     
,saturn  the spleen1 ,mercury the lungs1
 ,mars the bile1 ,venus the kidneys4    
,gold was a specific against diseases of
 the heart2 the liquor of ,luna         
7solution of silver7 cures diseases of  
the brain4 8,the remedies10 said        
,paracelsus1 8are subjected to the will 
of the stars1 and directed by  them4    
,you ought1 therefore1 to wait until    
heaven is favourable before  ordering a 
medicine40    ,the ,paracelsian         
physicians1 for the most part1 were a   
set of dangerous  fanatics1 who1 in     
their contempt for the principles of    
,hippocrates1  ,galen1 and ,avicenna1   
and in their reckless use of powerful   
remedies1  many of them metallic        
poisons1 wrought untold misery and      
mischief4 ,the  inevitable reaction set 
in1 and certain of the faculties1       
particularly  that of ,paris1 prohibited

 their licentiates1 under severe        
penalties1  from using chemical         
remedies4 ,it is not to be supposed1    
however1 that  all iatro-chemists were  
unscrupulous charlatans4 ,some of them  
clearly  perceived the significance and 
true value of the movement which        
,paracelsus may be credited with having 
originated4    ,andreas ,libavius1 or   
,libau1 originally a physician1 born in 
,halle1  is best known by his ,alchymia1
 published in #aeie1 which contains an  
account of the main chemical facts known
 in his time1 and is written  in clear  
and intelligible language1 in strong    
contrast to the mystery  and obscurity  
of his predecessors4 ,he was the        
discoverer of stannic  chloride1 still  
known as the fuming liquor of ,libavius1
 and described  a method of preparing   
oil of vitriol in principle identical   
with that  now made use of on a         
manufacturing scale4 ,he died in #afaf4 
,john ,baptist van ,helmont1 a scion of 
a noble ,brabant family1 was  born in   

,brussels in #aegg4 ,after studying     
philosophy and theology at  the         
,university of ,louvain1 he directed his
 attention to medicine1 and  made       
himself familiar1 in turn1 with every   
system from ,hippocrates to             
,paracelsus4 ,having spent some time in 
travel1 he settled on his estate  at    
,vilvorde1 and occupied himself with    
laboratory pursuits until his  death in 
#afdd4    ,van ,helmont was a scholarly1
 studious man1 and a philosopher4 ,a    
theosophist and prone to mysticism1 he  
had many of the mental  characteristics 
of ,paracelsus1 without his fanaticism  
and overweening  egotism4 ,he narrowed  
the number of ,aristotle's elements down
 to one1  and1 like ,thales1 considered 
water to be the true principle of all   
things1 supporting his theory by        
ingenious observations on the growth  of
 plants 7see p4 #bj74 ,he first employed
 the term gas1 and was aware  of the    
existence of various riform substances1 
anticipating ,hales1 who  has been      

styled the father of pneumatic          
chemistry1 in the discovery of  many    
gaseous phenomena4 ,he gave an accurate 
description of carbonic  acid gas1 which
 he termed gas sylvestre1 and showed    
that it is  produced from limestone and 
potashes in the fermentation of wine and
  beer1 and that it is formed in the    
body and in the earth4 ,the doctrines   
of the iatro-chemists were further      
spread by ,sylvius in ,holland1 and by  
,willis in ,england4    ,francis de le  
,bo ,sylvius1 born at ,hanau in #afad1  
became ,professor  of ,medicine in the  
,university of ,leyden1 where he        
exercised great  influence as a teacher 
until his death in #afgb4 ,medicine he  
treated  simply as a branch of applied  
chemistry1 and the vital processes of   
the animal body as purely chemical4 ,he 
freed the theory of physic from  much of
 the mystical absurdity introduced into 
it by ,paracelsus and  van ,helmont1 and
 by his practice brought chemical       
remedies once more  into vogue4 ,he was 

aware of the distinction between venous 
and arterial  blood1 and that the red   
colour of the latter was due to the     
influence  of air4 ,combustion and      
respiration he regarded as analogous    
phenomena4    ,thomas ,willis was born  
in ,wiltshire in #afba1 and while a     
student at  ,christchurch bore arms in  
the ,royalist army when ,oxford was     
garrisoned  for ,charles ,i4 ,in #affj  
he became ,sedleian ,professor of       
,natural  ,philosophy1 and ultimately   
settled in ,london as a physician4 ,he  
died in  #afge1 and was buried in       
,westminster ,abbey4    ,willis imagined
 that all vital actions were due to     
different kinds of  fermentation1 and   
that diseases were caused by            
abnormalities in the  fermentative      
process4 ,although a ,paracelsian as    
regards his theory of  the constitution 
of matter1 he followed ,sylvius and his 
pupil ,tachenius  in banishing mysticism
 from medicine4 ,he was a skilful       
anatomist1 and  gave the first accurate 

description of the brain and nerves4    
,other notable iatro-chemists were      
,angelus ,sala1 ,daniel ,sennert1       
,turquet  de ,mayerne 7who became body  
physician to ,james ,i471 ,oswald       
,croll1  ,adrian van ,mynsicht1 and     
,thomas ,lieber4 ,croll introduced the  
use of  potassium sulphate and succinic 
acid into medicine1 and ,van ,mynsicht  
that of tartar emetic4 ,various         
antimonial preparations had previously  
been employed by chemical physicians    
since the time of ,basil ,valentine1    
despite the ban of the ,parliament of   
,paris on their use4    ,the chief      
service of iatro-chemistry to science   
consisted in its  influence in bringing 
chemistry within the range of           
professional study1  whereby a great    
extension in its pursuit was effected1  
with the result  that a largely         
increased number of substances was      
discovered4 ,moreover1  this wider      
experience of chemical processes        
familiarised workers with  chemical     

phenomena in general1 and thereby       
contributed to lay the  foundations of a
 general theory of chemical action1     
which a succeeding  age strove to       
complete4    ,during the period of      
iatro-chemistry1 which may be said to   
have  extended from the first quarter of
 the sixteenth century to the latter    
half of the seventeenth1 chemistry was  
advanced along practical  lines by the  
labours of many men1 chief of whom were 
,agricola the  metallurgist1 ,palissy   
the potter1 and ,glauber the            
technologist4 ,these  men were primarily
 experimental chemists1 who took little 
or no part  in the fruitless polemics of
 the period1 but followed their         
avocation  in the true spirit of        
investigators1 and thereby enriched     
science with  many new and              
well-ascertained facts4    ,george      
,agricola1 born at ,glauchau in ,saxony 
in #adid1 was a  contemporary of        
,paracelsus4 ,after studying medicine at
 ,leipzig1 he  devoted himself to       

metallurgy and mineralogy1 first at     
,joachimsthal1  and published a number  
of works which were long deservedly     
regarded as  the leading treatises on   
these subjects4    ,in his ,libri ,,xii4
 de re ,metallica he gives an account of
 what was  known in his time respecting 
the extraction1 preparation1 and testing
  of ores4 ,he describes the smelting of
 copper and the recovery of the  silver 
which might be associated with it4 ,he  
also describes methods of  obtaining    
quicksilver1 and of purifying it by     
treatment with salt and  vinegar4 ,he   
gives a full description of the method  
of obtaining gold by  amalgamation1 and 
of recovering the mercury by            
distillation4 ,he gives  accounts of the
 smelting of lead1 tin1 iron1 bismuth1  
and antimony1  and describes the        
manufacture of salt1 nitre1 alum1 and   
green vitriol4    ,the whole work1 which
 is of folio size1 is illustrated by    
wood-cuts1  which give a faithful idea  
of the nature of the several operations1

 and  of the character of furnaces1     
trompes1 bellows1 and tools employed in 
them4 ,it is by far the most important  
technical work of the sixteenth         
century1 and it exercised great         
influence on the art of metallurgy4     
,the descriptions--at least as regards  
,european processes--are evidently  the 
result of personal observation4         
,agricola visited the mines1 and        
faithfully noted the different methods  
of sorting and washing the  ores1 the   
characters of which he accurately       
describes4 ,his accounts  of the various
 smelting operations are so detailed    
that it is obvious  they must have been 
put together after personal inquiry4    
,the study of  metallurgy1 indeed1 was  
the main object of his life2 and he     
devoted to  its pursuit even the pension
 which had been settled on him by       
,maurice1  ,elector of ,saxony4 ,he     
became ,mayor of ,chemnitz1 died there  
in #aeee1 and  was buried at ,zeitz4    
,bernard ,palissy lived throughout the  

greater portion of the sixteenth        
century4 ,although not a professed      
chemist1 nor a follower of any          
particular school1 he was an ardent     
self-taught experimentalist and a  keen 
and accurate observer1 who greatly      
enriched ceramic art by his             
discoveries4    ,johann ,rudolf ,glauber
 was born at ,karlstadt1 in ,bavaria1 in
 #afjd1  and after a restless life died 
in ,amsterdam in his sixty-fourth year4 
,he published an encyclopdia of chemical
 processes1 in which he  describes the  
preparation of a great variety of       
substances of technical  importance4    
,the greater number of the pharmacopias 
of the seventeenth  century are indebted
 to him for their descriptions of the   
mode of  manufacture of their official  
preparations4 ,he discovered sodium     
sulphate--his sal mirabile1 still       
frequently named after him--and         
introduced it into medicine4    ,during 
this period the common mineral          
acids--sulphuric1 hydrochloric1  and    

nitric--became ordinary articles of     
commerce1 and were used in the          
manufacture of a number of useful       
products1 chiefly inorganic salts4  ,a  
considerable number of metallic oxides  
were also in common use1 and  were      
applied to a variety of purposes in the 
arts4 ,the knowledge of  definite       
organic substances was much more        
limited4 ,acetic acid had long  been    
known1 but was first obtained in a      
concentrated form during this  period by
 the distillation of verdigris4 ,a      
number of other acetates  were also     
known1 as well as certain tartrates--as1
 for example1 salt of  sorrel1 ,rochelle
 or seignette salt1 and tartar emetic4  
,succinic and  benzoic acid were        
introduced into medicine1 and ,tachenius
 discovered  one of the characteristic  
acids of fat and oil 7stearic acid74    
,spirit  of wine was1 of course1 largely
 made and used in the preparation of    
tinctures and essences4 ,ether1         
originally known as oleum vitrioli      

dulce verum1 was first discovered by    
,valerius ,cordus2 and a mixture of  it 
with alcohol1 long known as ,hoffmann's 
drops1 appears to have been  employed as
 a medicine by ,paracelsus4             
,,chapter ,,vi    8,,the ,,sceptical    
,,chemist03 ,,the ,,dawn ,,of           
,,scientific ,,chemistry4      ,the     
latter half of the seventeenth century  
was a remarkable period  in the history 
of the intellectual development of      
,europe4 ,at that  time nearly every    
department of human knowledge seemed to 
have become  permeated by an eager      
spirit of scepticism1 inquiry1 and      
reform4  ,the foundation of the ,royal  
,society of ,london for ,improving      
,natural  ,knowledge1 the ,accademia del
 ,cimento of ,florence1 the ,academie   
,royale  at ,paris1 the ,berlin         
,academy1 all within a few years of each
 other1  was significant of the times4  
,chemistry was no longer to be a sacred 
mystery1 to be known only to priests1   
and its secrets jealously  guarded by   

them4 ,science had chafed under the     
domination of the  schoolmen2 it was now
 contemptuous of the dialectics of the  
,spagyrists4  ,experimentarian          
philosophy became even fashionable2 and 
the purely  deductive methods of the    
,peripatetics gradually gave place to   
the only  sound method of advancing     
natural knowledge4 ,the supremacy of the
  old philosophy may be said to have    
been first distinctly challenged  by    
,robert ,boyle4 ,the appearance in #affa
 of his book1 ,the ,sceptical  ,chemist1
 marks a turning-point in the history of
 chemistry4 ,the  8,chemico-physical    
,doubts and ,paradoxes0 raised by ,boyle
 8touching the  experiments whereby     
vulgar ,spagyrists are wont to endeavour
 to evince  their ,salt1 ,sulphur1 and  
,mercury to be the true ,principles of  
,things10  eventually sealed the fate of
 the doctrine of the tria prima1 and of 
the tenets of the school of ,paracelsus4
    ,in this treatise ,boyle sets out to
 prove that the number of the           

peripatetic elements or principles      
hitherto assumed by chemists is1 to  say
 the least1 doubtful4 ,the words        
8element0 and 8principle0 are used  by  
him as equivalent terms1 and signify    
those primitive and simple  bodies of   
which compounds may be said to be       
composed1 and into which  these         
compounds are ultimately resolvable4 ,he
 considered that the  matter of all     
bodies was originally divided into small
 particles of  different shapes and     
sizes1 and that these particles might   
unite into  small 8parcels10 not easily 
separable again2 that a great variety of
  compounds may arise from a few        
ingredients2 that various substances are
  obtainable from bodies by fire2 that  
fire is not the true and genuine        
analyser of bodies1 since it does not   
separate the principles of a  body1 but 
variously alters its nature2 and that   
some things obtained  from a body by    
fire were not its proper or essential   
ingredients4  ,three is not precisely   

and universally the number of the       
distinct  substances or elements into   
which all compound bodies are resolvable
  by fire1 inasmuch as some bodies      
afford more than three principles4      
,earth and water are as much chemical   
principles as salt1 sulphur1 and        
mercury4 ,even the limitation to five   
chemical principles is too narrow4      
,such is proved to be the case by the   
mode in which bodies1 animals  and      
vegetable1 grow1 and by the analysis of 
minerals and metals4 ,the  chemical     
theory of 8qualities0 of the ,spagyrists
 is narrow1 defective1  and uncertain2  
supposes things not proved2 is often    
superfluous1 and  frequently contradicts
 the phenomena of nature4 ,the          
8principles0 found  in bodies cannot be 
the cause of their qualities1 since     
contrary  qualities are ascribed to the 
same body4 ,he concludes1 therefore1    
that  the ,paracelsian elements--their  
8salt10 8sulphur10 and 8mercury0--are   
not  the first and most simple          

principles of bodies2 but that these    
consist1  at most1 of concretions of    
corpuscles or particles more simple than
  they1 and possessing the radical and  
universal properties of volume1  shape1 
and motion4    ,illustration3 ,,robert  
,,boyle4    ,from a painting by ,f4     
,kerseboom in the possession of the     
,royal ,society4    ,robert ,boyle1     
fourteenth child and the seventh and    
youngest son of  ,richard the 8,great0  
,earl of ,cork1 and ,lord ,high         
,chancellor of ,ireland1  was born at   
,lismore in #afbf4 ,he was educated at  
,eton under ,sir ,henry  ,wotton1 and1  
after spending some years on the        
,continent1 settled at  ,stalbridge in  
,dorset1 where he owned a manor4 ,he    
became a member of  what was known as   
the ,invisible ,college1 a small        
association of men  interested in the   
new philosophy1 who met at each other's 
houses in  ,london1 and occasionally at 
,gresham ,college1 8to discourse and    
consider  of philosophical inquiries and

 such as related thereunto40 ,the       
meetings  were subsequently held in     
,oxford1 and ,boyle took up his         
residence there  in #afed4 ,here--in    
association with ,wilkins2 ,john ,wallis
 and ,seth ,ward1  the two ,savilian    
,professors of ,geometry and ,astronomy2
 ,thomas ,willis1  the physician1 then  
student of ,christ ,church2 ,christopher
 ,wren1 then  ,fellow of ,all ,souls'   
,college2 ,goddard1 ,warden of ,merton2 
and ,ralph  ,bathurst1 ,fellow of       
,trinity1 and afterwards its            
,president--they sought  to cultivate   
the new philosophy1 8being satisfied    
that there was no  certain way of       
arriving at any competent knowledge     
unless they made a  variety of          
experiments upon natural bodies4 ,in    
order to discover what  phenomena they  
would produce1 they pursued that method 
by themselves  with great industry1 and 
then communicated their discoveries to  
each  other40 ,the ,invisible ,college  
eventually grew into the ,royal         

,society1  which received its charter in
 #affc4 ,boyle removed to ,london in    
#affh1  and died there on ,december     
#cast1 #afia1 in the sixty-fifth year of
 his  age4    ,a man of integrity1      
modest1 simple1 and unassuming1 ,boyle  
was an  assiduous and true student of   
science1 and practically the whole of   
his life was given to its pursuit4 ,his 
social position1 his example1  the      
purity of his private life1 and the fame
 of his discoveries made  his personal  
influence very considerable1 to the     
great advantage of  science in this     
country4 ,his experimental work was of a
 high order4  ,he introduced the        
air-pump into ,england1 and his         
8pneumatical engine0  enabled him to    
discover many of the fundamental        
properties of a gas1  notably the       
relation of its volume to pressure4 ,he 
also discovered  the dependence of the  
boiling point of a liquid upon          
atmospheric  pressure1 explained the    
action of the syphon1 the effect of the 

air  on the vibration of a pendulum and 
on the propagation of sound1 and  made  
experiments on the nature of flame1 and 
on the relation of air to  combustion   
and respiration4 ,in his ,history of    
,fluidity he seeks to  show that a body 
seems to be fluid by consisting of      
corpuscles touching  one another only in
 some parts of their surfaces2 whence1  
by reason of  the numerous spaces       
between them1 they easily glide along   
each other  till they meet with some    
resisting body to whose internal surface
 they  exquisitely accommodate          
themselves4 ,he considers the requisites
 of  fluidity to be chiefly these3 ,the 
smallness of the component particles1   
their determinate figure1 the vacant    
spaces between them1 and the fact  of   
their being agitated variously and apart
 by their own innate motion  or by some 
thinner substance which tosses them     
about in its passage  through them4 ,his
 published works contain many           
well-authenticated  chemical facts1     

which are commonly held to be the       
discovery of a  later time4 ,he prepared
 acetone by the distillation of the     
acetates  of lead and lime2 and he      
isolated methyl alcohol from the        
products of  the destructive            
distillation of wood4 ,he was one of the
 earliest to  insist on the necessity of
 studying the forms of crystals4 ,he saw
 in  their formation proof that the     
internal motions1 configuration1 and    
position of the integral parts are all  
that is necessary to account for        
alterations and diversities in outward  
character4 ,some of the stock           
illustrations of our lecture-rooms were 
of his contrivance4 ,thus he            
illustrated the expansive power of      
freezing water by bursting a plugged    
gun-barrel filled with water by         
solidifying the water by means of a     
mixture of snow and salt--a freezing    
mixture which he first introduced4      
,boyle was the first to formulate our   
present conception of an element  in    

contradistinction to that of the ,greeks
 and the schoolmen who  influenced the  
theories of the iatro-chemists4 ,in the 
sense understood  by him1 the           
,aristotelian elements were not true    
elements1 nor were the  salt1 sulphur1  
and mercury of the school of            
,paracelsus4 ,he was also  the first to 
define the relation of an element to a  
compound1 and to  draw the distinction  
we still make between compounds and     
mixtures4 ,he  revived the atomic       
hypothesis1 and explained chemical      
combination on  the basis of affinity4  
,he contended that one of the main      
objects of  the chemist was to ascertain
 the nature of compounds2 and thereby he
  stimulated the application of analysis
 to chemistry4 ,boyle discovered a      
number of qualitative reactions1 and    
applied them to the detection of        
substances1 either free or in           
combination4    ,but ,boyle's greatest  
service to learning consisted in the new
 spirit  he introduced into chemistry4  

,henceforward chemistry was no longer   
the mere helpmeet of medicine4 ,she     
became an independent science1 the      
principles of which were to be          
ascertained by experiment2 a science  to
 be studied with the object of          
discovering the laws regulating the     
phenomena with which it is              
concerned--and hence elucidating truth  
for  truth's sake4 ,the old philosophy  
of the ,greeks had1 as we have seen1    
become merged into the doctrine of the  
iatro-chemists2 and this was now  to be 
purified from the theosophical mysticism
 with which ,paracelsus  and his        
followers had enshrouded it4 8,the      
dialectical subtleties of  the schoolmen
 much more10 says ,boyle1 8declare the  
wit of him that  uses them than increase
 the knowledge or remove the doubts of  
sober  lovers of truth4444 ,for in such 
speculative inquiries where the naked   
knowledge of the truth is the thing     
principally aimed at1 what does  he     
teach me worth thanks1 that does not1 if

 he can1 make his notion  intelligible  
to me1 but by mystical terms and        
ambiguous phrases darkens  what he      
should clear up1 and makes me add the   
trouble of guessing at  the sense of    
what he equivocally expresses1 to that  
of learning the  truth of what he seems 
to deliver40 ,the influence of the new  
spirit  thus infused into the science by
 ,boyle is seen in the general style  of
 chemical literature at the end of the  
seventeenth century1 when  compared with
 that of the close of the sixteenth4    
,the mysticism and  obscurity of the    
alchemists were no longer tolerated4    
,boyle was slender and tall1 with a     
countenance pale and emaciated4  ,his   
constitution was delicate and his body  
feeble1 and it was only  by strict      
attention to diet and regularity of     
exercise that he  accomplished what he  
did4 ,although he suffered occasionally 
from an  excessive lowness of spirits1  
there was nothing morose or ascetic  in 
his nature4 ,he was never married1      

although1 says his friend ,john         
,evelyn1 8few men were more facetious   
and agreeable in conversation with  the 
ladies whenever he happened to be       
engaged among them40    ,kindly1        
courteous1 charitable2 unaffected1 and  
temperate in his  manner of life1 ,boyle
 enjoyed the respect and esteem of all  
his  contemporaries4 ,it was said of him
 that he was never known to have        
offended any person in his whole life by
 any part of his deportment4  ,he       
allowed himself a great deal of decent  
cheerfulness1 and had about  him all the
 tenderness of good nature1 as well as  
all the softness of  friendship4 ,these 
gave him a large share of other men's   
concerns1 for  he had a quick sense of  
the miseries of mankind4 ,although a    
philosopher  in the broadest sense of   
that term1 his peculiar and favourite   
study  was chemistry1 8in which10 says  
,bishop ,burnet1 8he engaged with none  
of those ravenous and ambitious designs 
that drew many into them4 ,his  design  

was only to find out nature1 to see into
 what principles things  might be       
resolved1 and of what they were         
compounded40    ,john ,kunkel1 born in  
#afcj1 was the son of an alchemist      
attached  to the ,court of the ,duke of 
,holstein4 ,after serving his father for
  some years1 he obtained employment as 
chemist and pharmacist under  the ,dukes
 ,charles and ,henry1 of ,lauenburg4 ,he
 subsequently entered  the laboratory at
 ,dresden of ,john ,george ,,ii41       
,elector of ,saxony1  and1 after        
teaching chemistry at the ,university of
 ,wittenburg1 then  famous as a medical 
school1 he accepted an invitation to    
take charge  of the glass works and     
laboratory of the ,elector of           
,brandenburg1 at  ,berlin4 ,the         
laboratory was burnt down1 and then     
,charles ,,xi4 of ,sweden  called him to
 ,stockholm and ennobled him as ,baron  
von ,lowenstiern4 ,he  died in          
,stockholm in #agjb4 ,kunkel's chief    
work is his ,laboratorium  ,chymicum1   

published after his death4 ,it was      
written in ,german4 ,in  it ,kunkel     
relates how he acquired possession of a 
knowledge of the  manufacture of        
,baldwin's phosphorus1 and of the       
phosphorus discovered  by               
,brand--perhaps the most important1 as  
it certainly was one of the  most       
striking1 of the chemical discoveries of
 the seventeenth century4  ,kunkel did  
much to liberate chemical literature    
from the mysticism and  obscurity of    
alchemy4 ,he was scornful of the        
theories of the adepts1  and            
contemptuous of their tria prima4       
,i1 old man that ,i am1 who have been   
occupied with chemistry for    sixty    
years1 have never yet been able to      
discover their fixed    sulphur1 or how 
it enters into the composition of       
metals4444    ,moreover1 they are not   
agreed among themselves respecting the  
kind    of sulphur4 ,the sulphur of one 
is not the sulphur of the other4 ,to    
that one may reply that each is at      

liberty to baptise his child as    he   
likes4 ,i agree3 you may even1 if you   
are so disposed1 call an    ass a cow2  
but you will never make anyone believe  
that your cow is    an ass4    ,as to   
the alkahest he says3--      ,there has 
been much discussion concerning this    
grand natural    solvent4 ,some derive  
it from the ,latin--akali est2 others   
from the    two ,german words all geist 
7all gas72 lastly1 others say it is     
from alles est 7that's all74 ,as to     
myself1 ,i do not believe in    ,van    
,helmont's universal solvent4 ,i call it
 by its true name--alles    ,lgen heist1
 or alles ,lgen ist 7it is all a lie74  
,kunkel discovered the secret of the    
manufacture of aventurine glass  and of 
ruby glass by means of the purple of    
,cassius--a product from  gold first    
obtained by a doctor of medicine of that
 name in ,hamburg4  ,he made            
observations on fermentation and        
putrefaction--recognised that  alum was 
a double salt 7salduplicatum72 described

 the present method  of repairing pure  
silver1 and of parting gold and silver  
by means  of sulphuric acid4 ,he also   
described the mode of preparing a number
  of essential oils1 detected the       
presence of stearopten in oils1 and     
discovered nitrous ether4    ,john      
,joachim ,becher1 the son of a ,lutheran
 minister1 was born at  ,speyer in      
#afce4 ,owing to the death of his father
 and the devastation  of the family     
property during the ,thirty ,years'     
,war1 ,becher had a  hard struggle with 
poverty during his youth1 and led a     
restless1  wandering life4 ,in #afff he 
was ,professor of ,medicine in the      
,university  of ,mayence4 ,subsequently 
he went to ,munich as head of the finest
  laboratory in ,europe1 but1           
quarrelling with the ,chancellor of the 
,bavarian ,court1 betook himself to     
,vienna4 ,after a short stay there1 he  
quitted ,austria for ,holland1 and      
established himself in ,haarlem4 ,here  
he proposed to the ,states-,general to  

extract gold from the sand-dunes2  but1 
the project failing1 he left for        
,england and visited the ,cornish       
mines4 ,on the invitation of the ,duke  
of ,mecklenburg-,gstrow1 he  returned to
 ,germany4 ,shortly afterwards 7in      
#afhb7 he died1 in the  forty-seventh   
year of his age4 ,becher's name is      
remembered mainly in  connection with   
his theory of combustion1 which1 as we  
shall see1  was subsequently developed  
by ,stahl into the theory of            
,phlogiston--a  generalisation which    
dominated chemistry until near the close
 of the  eighteenth century4    ,john   
,mayow1 born in ,cornwall in #afde1 was 
a practising physician1  whose name     
chiefly lives by virtue of his clear    
recognition of the  substance or        
principle in the air which is concerned 
in combustion1  the calcination of      
metals1 respiration1 and the conversion 
of venous  into arterial blood4 ,this   
substance1 which he found to be         
contained in  saltpetre1 he called      

spiritus igno-areus or nitro areust4    
,mayow  died at the age of thirty-four4 
,had he been able to follow up his      
observations1 he might have influenced  
very materially the development  of     
theoretical chemistry4 ,as it was1 he   
was practically overlooked by  his      
contemporaries1 and the real            
significance of his work was not        
appreciated until long afterwards4      
,nicolas ,lemery1 also born in #afde1   
wrote a ,cours de ,chimie1 one  of the  
best text-books of the time1 which      
passed through as many as  thirteen     
editions1 and was translated into       
,english1 ,german1 ,latin1  ,italian1   
and ,spanish4    ,in this book he       
strove1 as he says1 to express himself  
clearly1 and to  avoid the obscurities  
which were to be found in the authors   
who had  preceded him4      ,the fine   
imaginations of other philosophers      
concerning their    physical principles 
may elevate the spirit by their grand   
ideas1    but they prove nothing        

demonstratively4 ,and1 as chemistry is a
    science of observation1 it can only 
be based on what is palpable    and     
demonstrative4    ,nicolas ,lemery1 who 
is not to be confounded with his son    
,louis1 also a  chemist1 made a         
considerable number of contributions to 
pharmaceutical  chemistry2 and his      
,pharmacope ,universelle1 ,dictionnaire 
,universel  des ,drogues ,simples1 and  
,trait de l',antimoine were standard    
works  in their day4    ,lemery was at  
one time a ,protestant1 and on the      
revocation of the ,edict  of ,nantes    
fled to ,england2 but1 embracing        
,catholicism1 he returned to  ,paris1   
re-established his pharmacy1 and was    
elected into the ,academy in  #afii4 ,he
 died in #agae4    ,william ,homberg1   
born in ,batavia in #afeb1 was          
originally intended  for the profession 
of law1 but1 becoming attached to       
science1 studied  botany and medicine in
 ,padua1 chemistry at ,bologna and in   
,london1  mechanics and optics at ,rome1

 and anatomy at ,leyden4 ,in the course 
of  his travels he visited the mines of 
,germany1 ,hungary1 ,bohemia1 and       
,sweden4 ,in #afhb he was invited to    
,paris by ,colbert1 and in #afia was    
made a member of the ,academy and was   
placed by the ,duke of ,orleans in      
charge of his laboratory--then one of   
the finest in ,europe4 ,homberg  married
 the daughter of ,dodart1 the physician4
 ,she became an expert  prparateur1 and 
was of great assistance to him in his   
experimental  inquiries4 ,he first made 
known the existence of phosphorus in    
,france1  discovered by ,brand1 of      
,hamburg1 and he described the          
phosphorescent  salt associated with his
 name4 ,he made important observations  
on the  saturation of alkalis by acids1 
and was aware that they combined in     
different proportions4 ,he was an       
industrious worker1 and1 with the       
exception of ,cassini1 was the most     
active member of the ,academy4 ,he  died
 on ,september #bdth1 #agae4    ,next to

 ,boyle1 perhaps the most active agent  
in emancipating chemistry  from the yoke
 of alchemy was ,boerhaave1 who1 by his 
teaching as  ,professor of ,physic1     
raised the ,university of ,leyden to the
 summit of  its fame4    ,hermann       
,boerhaave1 the son of a minister1 was  
born near ,leyden1 in  #affh4 ,he       
occupied himself in turn with theology1 
classics1 mathematics1  chemistry1 and  
botany1 when he turned to physic1 and1  
after a course of  study at the         
,university of ,harderwyk1 in           
,gelderland1 began to practise4  ,in    
#agjb he was appointed to a lectureship1
 and eventually to the ,chair  of       
,medicine1 in the ,university of        
,leyden1 of which he became ,rector  in 
#agad4 ,his reputation as a teacher     
spread throughout ,europe1 and  steadily
 increased until his death4             
,illustration3 ,,hermannus ,,boerhaave  
,medicin1 ,botanices1 ,chemi            
,collegii practici1 in ,,acad4 ,,lugd4  
,,bat4    ,,professor ,,ordinarius4     

,after a painting by ,t4 ,wandelaar     
,boerhaave was one of the most learned  
men of his age1 and singularly  well    
cultured1 not only in science but in    
history1 poetry1 and polite  literature4
 ,he conversed in ,english1 ,french1 and
 ,german1 and read  ,italian and        
,spanish with facility4 8,the ,latin he 
spoke extempore in  lectures or         
conversation was so clear that1 with his
 action1 method1  and the aptness of his
 similes1 he could level the most       
abstruse  points to the meanest         
capacities40#b ,he was fond of music1   
and a good  performer on several        
instruments1 particularly the lute4 ,he 
delighted  to welcome musicians to his  
house4 ,his profession as a physician   
brought him wealth1 much of which he    
spent in horticulture2 and the  garden  
of his country seat1 nearly eight acres 
in extent1 was enriched  with all the   
exotic trees he could procure and induce
 to flourish in  the climate of         
,holland4        #b ,burton1 ,life of   

,boerhaave1 p4 #eh et seq4    ,boerhaave
 was of a robust frame and healthy      
constitution1 early inured  to constant 
exercise and the inclemencies of        
weather4 ,his stature was  rather tall1 
and his habit corpulent4 ,he had a large
 head1 short neck1  florid complexion1  
light brown curled hair 7for he did not 
wear a wig71  an open countenance1 and  
resembled ,socrates in the flatness of  
his nose  and his natural urbanity4 ,he 
died at ,leyden on ,september #bcrd1    
#agch1 in  the seventieth year of his   
age4    ,as a chemist ,boerhaave is     
chiefly known by his ,elementa ,chemia1 
published in #agcb--the most complete   
and most luminous chemical treatise  of 
its time1 translations of which appeared
 in the chief ,european  languages4 ,the
 work is divided into three main parts4 
,the first is  concerned with the origin
 and progress of the art1 and with the  
personal history of its most            
distinguished cultivators4 ,the second  
and  largest part deals with the attempt

 to form a system of chemistry based  on
 such observational matter as seemed    
well established4 ,the third  consists  
of a collection of chemical processes   
relating to the analysis  or            
decomposition of bodies1 grouped under  
the heads of 8vegetables10  8animals10  
and 8fossils0--the beginnings1 in fact1 
of subdivision of the  science into     
organic and inorganic chemistry4    ,as 
regards his belief in alchemy1          
,boerhaave was an agnostic3 he neither  
affirmed nor denied the possibility of  
transmutation4 ,in this respect  he     
resembled ,newton and ,boyle4 ,boyle1   
indeed1 was singularly cautious  and    
reticent in his references to           
alchemistic matters4 ,as was said of    
him by ,shaw1 he was too wise to set any
 bounds to nature3 he was not  prone to 
say that every strange thing must needs 
be impossible1 for  he saw strange      
things every day1 and was well aware    
that there are  powerful forces in the  
world of whose laws and modes of action 

he knew  nothing4 ,with that wariness   
which was habitual to him1 he was wont  
to  say that 8those who had seen them   
might better believe them than those    
who had not02 and he was modest enough  
to suppose that ,paracelsus or  ,helmont
 might conceivably know of agents of    
which he was ignorant4    ,boerhaave    
unquestionably spent much time in the   
study of alchemical  works1 particularly
 those of ,paracelsus and ,helmont1     
which he  repeatedly read4 ,the         
,philosophical ,transactions of the     
,royal ,society  contain the results of 
a laborious but fruitless investigation 
by  him on quicksilver1 which he        
undertook in the hope of discovering    
the seminal or engendering matter which1
 on the old theory of the  generation of
 metals1 was supposed to be contained in
 mercury4  ,but although1 as he relates1
 he tortured it by 8conquassation1      
trituration1 digestion1 and by          
distillation1 either alone or           
amalgamated with lead1 tin1 or gold1    

repeating this operation to #eaa  or    
even to #hgg distillations10 the mercury
 appeared only 8rather more  bright and 
liquid1 without any other variation in  
its form or virtues1  and acquired very 
little1 if any1 increase of its specific
 gravity40    ,stephen ,hales           
7#afgg-agfa71 an ingenious divine--he   
held the perpetual  curacy of           
,teddington1 and lived practically the  
greater part of his  life               
there--distinguished as a physiologist  
and inventor1 occupied  himself in      
chemical pursuits1 and made a number of 
observations on the  production of      
gaseous substances4 ,his results were   
communicated to the  ,royal ,society and
 subsequently republished1 in a         
collected form1 under  the title of     
,statical ,essays4 ,in these experiments
 he used methods  very similar in       
principle to those subsequently employed
 by ,priestley4  ,it is evident from his
 description of his experiments that he 
must  have prepared a considerable      

number of gaseous substances--hydrogen1 
carbonic acid1 carbonic oxide1 sulphur  
dioxide1 marsh gas1 etc4--but he  seems 
to have made no systematic attempt to   
study their properties1  as he          
considered that they were simply air1   
modified or 8tinctured0  by the presence
 of substances which he regarded as more
 or less  fortuitous4 ,prior to the time
 of ,black all forms of gaseous         
substance  were regarded as             
substantially identical--in fact1 as    
being air1  as understood by the        
,ancients--a simple elementary          
substance4 ,it was  ,black's study of   
carbonic acid which first clearly       
established that  there were essentially
 distinct varieties of gaseous matter4  
,,chapter ,,vii    ,,phlogistonism      
,even before the appearance of ,the     
,sceptical ,chemist there was a  growing
 conviction that the old hypotheses as  
to the essential nature  of matter were 
inadequate and misleading4 ,we have seen
 how the four  8elements0 of the        

,peripatetics had become merged into the
 tria  prima--the 8salt10 8sulphur10 and
 8mercury0--of the ,paracelsians4 ,as   
the phenomena of chemical action became 
better known1 the latter                
iatro-chemists--or1 rather1 that section
 of them which recognised that          
chemistry had wider aims than to        
minister merely to medicine--felt that  
the conception of the tria prima1 as    
understood by ,paracelsus and  his      
followers1 was incapable of being       
generalised into a theory of  chemistry4
 ,becher1 while clinging to the         
conception of three primordial          
substances as making up all forms of    
matter1 changed the qualities  hitherto 
associated with them4 ,according to the 
new theory1 all matter  was composed of 
a mercurial1 a vitreous1 and a          
combustible substance  or principle1 in 
varying proportions1 depending upon the 
nature of the  particular form of       
matter4 ,when a body was burnt or a     
metal calcined1  the combustible        

substance--the terra pinguis of         
,becher--escaped4    ,this attempt to   
connect the phenomena of combustion and 
calcination  with the general phenomena 
of chemistry was still further developed
  by ,stahl1 and was eventually extended
 into a comprehensive theory of         
chemistry1 which was fairly satisfactory
 so long as no effort was made  to test 
its sufficiency by an appeal to the     
balance4    ,george ,ernest ,stahl1 who 
developed ,becher's notion into the     
theory of  phlogiston 7--burnt71 and    
thereby created a generalisation  which 
first made chemistry a science1 was born
 at ,anspach in #affj1  became          
,professor of ,medicine and ,chemistry  
at ,halle in #afic1 physician  to the   
,king of ,prussia in #agaf1 and died in 
,berlin in #agcd4    ,stahl contributed 
little or nothing to practical          
chemistry2 and no new  fact or discovery
 is associated with his name4 ,his      
service to science  consists in the     
temporary success he achieved in        

grouping chemical  phenomena1 and in    
explaining them consistently by a       
comprehensive  hypothesis4    ,the      
theory of phlogiston was originally     
broached as a theory of  combustion4    
,according to this theory1 bodies such  
as coal1 charcoal1  wood1 oil1 fat1     
etc41 burn because they contain a       
combustible  principle1 which was       
assumed to be a material substance and  
uniform  in character4 ,this substance  
was known as phlogiston4 ,all           
combustible  bodies were to be regarded1
 therefore1 as compounds1 one of their  
constituents being phlogiston3 their    
different natures depended  partly upon 
the proportion of phlogiston they       
contain1 and partly  upon the nature and
 amount of their other constituents4 ,a 
body1 when  burning1 was parting with   
its phlogiston2 and all the phenomena of
  combustion--the flame1 heat1 and      
light--were caused by the violence  of  
the expulsion of that substance4        
,certain metals--as1 for example1       

zinc--could be caused to burn1 and      
thereby to yield earthy substances1     
sometimes white in colour1 at other     
times variously coloured4 ,these  earthy
 substances were called calces1 from    
their general resemblance  to lime4     
,other metals1 like lead and mercury1   
did not appear to burn2  but on heating 
them they gradually lost their metallic 
appearance1 and  became converted into  
calces4 ,this operation was known as    
calcination4  ,in the act of burning or 
of calcination phlogiston was expelled4 
,hence  metals were essentially         
compound3 they consisted of phlogiston  
and a  calx1 the nature of which        
determined the character of the metal4  
,by  adding phlogiston to a calx the    
metal was regenerated4 ,thus1 on heating
  the calx of zinc or of lead with coal1
 or charcoal1 or wood1 metallic  zinc or
 lead was again formed4 ,when a candle  
burns1 its phlogiston  is transferred to
 the air2 if burned in a limited supply 
of air1  combustion ceases1 because the 

air becomes saturated with phlogiston4  
,respiration is a kind of combustion    
whereby the temperature of the body  is 
maintained4 ,it consists simply in the  
transference of the phlogiston  of the  
body to the air4 ,if we attempt to      
breathe in a confined  space1 the air   
becomes eventually saturated with the   
phlogiston1 and  respiration stops4 ,the
 various manifestations of chemical     
action1 in  like manner1 were attributed
 to this passing to and fro of          
phlogiston4  ,the colour of a substance 
is connected with the amount of         
phlogiston  it contains4 ,thus1 when    
lead is heated1 it yields a yellow      
substance  7litharge72 when still       
further heated1 it yields a red         
substance 7red  lead74 ,these           
differences in colour were supposed to  
depend upon the  varying amount of      
phlogiston expelled4    ,the doctrine of
 phlogiston was embraced by nearly all  
,stahl's ,german  contemporaries1       
notably by ,marggraf1 ,neumann1 ,eller1 

and ,pott4 ,it  spread into ,sweden1 and
 was accepted by ,bergman and ,scheele2 
into  ,france1 where it was taught by   
,duhamel1 ,rouelle1 and ,macquer2 and   
into  ,great ,britain1 where its most   
influential supporters were ,priestley  
and  ,cavendish4 ,it continued to be the
 orthodox faith until the last quarter  
of the eighteenth century1 when1 after  
the discovery of oxygen1 it was         
overturned by ,lavoisier4    ,during the
 sway of phlogiston chemistry made many 
notable advances--not  by its aid1 but  
rather in spite of it4 ,as a matter of  
fact1 until  the time of ,lavoisier few1
 if any1 investigations were made with  
the  express intention of testing it1 or
 of establishing its sufficiency4  ,when
 new phenomena were observed the attempt
 was no doubt made to  explain them by  
its aid1 frequently with no satisfactory
 result4  ,indeed1 even in the time of  
,stahl1 facts were known which it was   
difficult or impossible to reconcile    
with his doctrine2 but these  were      

either ignored1 or their true import    
explained away4 ,although1  therefore1  
these advances were in no way connected 
with phlogiston1  it will be convenient 
to deal with the more important of them 
now1  inasmuch as they were made during 
the phlogistic period4    ,with the     
exception of ,marggraf1 ,stahl's ,german
 contemporaries  contributed few facts  
of first-rate importance to chemistry4  
,pott1  who was born at ,halberstadt in 
#afib and become ,professor of          
,chemistry  in ,berlin in #agcg1 is     
chiefly remembered by his work on       
porcelain1  the chemical nature and mode
 of origin of which he first elucidated4
  ,marggraf1 born in ,berlin in #agji1  
was one of the best analysts of his     
age4 ,he first clearly distinguished    
between lime and alumina1 and was  one  
of the earliest to point out that the   
vegetable alkali 7potash7  differed from
 the mineral alkali 7soda74 ,he also    
showed that gypsum1  heavy spar1 and    
potassium sulphate were analogous in    

composition4  ,he clearly indicated the 
relation of phosphoric acid to          
phosphorus1  described a number of      
methods of preparing that acid1 and     
explained the  origin of the phosphoric 
acid in urine4    ,of the ,swedish      
chemists of that period1 the most       
notable was ,scheele4    ,carl ,wilhelm 
,scheele was born in #agdb at           
,stralsund4 ,when fourteen  years of age
 he was apprenticed to an apothecary at 
,gothenburg1 and  began the study of    
experimental chemistry1 which he        
continued to  prosecute as an apothecary
 at ,malm1 ,stockholm1 ,upsala1 and     
eventually  at ,kping on ,lake ,malar1  
where he died in #aghf1 in the          
forty-third year  of his age4 ,during   
the comparatively short period of his   
scientific  activity ,scheele made      
himself the greatest chemical discoverer
 of his  time4    ,illustration3 ,,carl 
,,wilhelm ,,scheele4    ,from the statue
 by ,brjeson at ,stockholm4    ,he first
 isolated chlorine1 and determined the  

individuality of  manganese and baryta4 
,he was an independent discoverer of    
oxygen1  ammonia1 and hydrogen chloride4
 ,he discovered also hydrofluoric1      
nitro-sulphonic1 molybdic1 tungstic1 and
 arsenic1 among the inorganic  acids2   
and lactic1 gallic1 pyrogallic1 oxalic1 
citric1 tartaric1 malic1  mucic1 and    
uric acids among the organic acids4 ,he 
isolated glycerine  and milk-sugar2     
determined the nature of microcosmic    
salt1 borax1 and  ,prussian blue1 and   
prepared hydrocyanic acid4 ,he          
demonstrated that  graphite is a form of
 carbon4 ,he discovered the chemical    
nature of  sulphuretted hydrogen1       
arsenuretted hydrogen1 and the green    
arsenical  pigment known by his name4   
,he invented new processes for preparing
  ether1 powder of algaroth1 phosphorus1
 calomel1 and magnesia alba4  ,he first 
prepared ferrous ammonium sulphate1     
showed how iron may be  analytically    
separated from manganese2 and described 
the method of  breaking up mineral      

silicates by fusion with alkaline       
carbonates4  ,scheele's contributions to
 chemical theory were slight and        
unimportant1  but as a discoverer he    
stands pre-eminent4    ,of the ,french  
phlogistians we have space only to      
mention ,duhamel and  ,macquer4         
,henry ,louis ,duhamel du ,monceau was  
born at ,paris in #agjj4 ,he was one  of
 the earliest to make experiments on    
ossification1 and one of the  first to  
detect the difference between potash and
 soda4    ,peter ,joseph ,macquer was   
born in #agah at ,paris4 ,he            
investigated  the nature of ,prussian   
blue 7discovered by ,diesbach1 of       
,berlin1 in  #agaj71 worked on platinum1
 wrote one of the best text-books of his
  time1 published a dictionary of       
chemistry1 and was an authority of the  
chemistry of dyeing4    ,in addition to 
those already mentioned1 the most       
notable names as  workers in chemistry  
in ,great ,britain during the eighteenth
 century are  ,black1 ,priestley1 and   

,cavendish4    ,joseph ,black was born  
in #agbh at ,bordeaux1 where his father 
was  engaged in the wine trade4 ,a      
student of the ,university of ,glasgow1 
he  became its ,professor of ,chemistry 
in #agef4 ,in #agff he was transferred  
to the ,chemical ,chair of the          
,university of ,edinburgh1 and died in  
#agii4  ,black published only three     
papers1 the most important of which is  
entitled ,experiments upon ,magnesia    
,alba1 ,quicklime1 and ,other ,alkaline 
,substances4 ,he proved that magnesia is
 a peculiar earth differing  in         
properties from lime4 ,lime is a pure   
earth1 while limestone is  carbonate of 
lime4 ,he showed that magnesia will also
 combine with  carbonic acid1 and he    
explained that the difference between   
the mild  and caustic alkalis is that   
the former contain carbonic acid1       
whereas  the latter do not4 ,he also    
explained how lime is able to convert   
the  mild alkalis into caustic alkalis4 
,simple and well known as these  facts  

are to-day1 their discovery in #agee    
excited great interest1 and  marked an  
epoch in the history of chemistry4      
,black's name is associated  with the   
discovery of latent and specific heat1  
and he made the first  determinations of
 the amount of heat required to convert 
ice into water4    ,illustration3       
,,joseph ,,priestley4    ,from a        
mezzotint after ,fuseli in the          
possession of the ,royal ,society4      
,joseph ,priestley1 the son of a        
clothdresser1 was born in #agcc at      
,fieldhead1 near ,leeds4 ,when seven    
years of age1 on the death of his       
mother1 he was taken charge of by his   
aunt1 and was educated for  the         
,nonconformist ministry1 eventually     
becoming a ,unitarian4 ,he was  first   
attracted to science by the study of    
electricity1 of which he  compiled a    
history4 ,at ,leeds1 where he had charge
 of the ,mill ,hill  congregation1 he   
turned his attention to chemistry1      
mainly from the  circumstance that he   

lived near a brewery and had the        
opportunity  of procuring large         
quantities of carbonic acid1 the        
properties of  which he carefully       
studied4 ,he abandoned the ministry for 
a time to  become librarian and literary
 companion to ,lord ,shelburne1 with    
whom  he remained seven years4 ,during  
this time he industriously pursued      
chemical inquiry1 and discovered a large
 number of riform bodies--viz41  nitric 
oxide1 hydrogen chloride1 sulphur       
dioxide1 silicon fluoride1  ammonia1    
nitrous oxide1 and1 most important of   
all from the point of  view of chemical 
theory1 oxygen gas4 ,priestley's work   
gave a remarkable  impetus to the study 
of pneumatic chemistry4 ,it exercised   
great  influence on the extension of    
chemical science1 and--in other hands   
than his--on the development of chemical
 theory4 ,the most important of  his    
contributions to science are contained  
in his ,experiments and  ,observations  
on ,different ,kinds of ,air4 ,this work

 not only gives an  account of the      
methods by which he isolated the gases  
he discovered1  but describes a great   
number of incidental observations1 such 
as the  action of vegetation on respired
 air1 showing that the green parts of   
plants are able in sunlight to decompose
 carbonic acid and to restore  oxygen to
 the atmosphere4 ,he was1 in fact1 one  
of the earliest to trace  the specific  
action of animals and plants on         
atmospheric air1 and to  show how these 
specific actions maintained its purity  
and constancy of  composition4 ,he      
initiated the art of eudiometry 7gas    
analysis71 and  was the first to        
establish that the air is not a simple  
substance1  as imagined by the ancients4
 ,priestley is to be credited with the  
invention of soda-water1 which he       
prepared as a remedy for scurvy2  and   
his name is connected with the so-called
 pneumatic trough--a  simple enough     
piece of apparatus1 but one which proved
 to be of the  greatest service to him  

in his inquiries4    ,after leaving     
,lord ,shelburne1 ,priestley removed to 
,birmingham and  resumed his ministry4  
,his religious and political opinions   
made him  obnoxious to the ,church and  
,state party2 and during the riots of   
#agia his house was wrecked1 his books  
and apparatus destroyed1 and  his life  
endangered4 ,eventually he emigrated to 
,america1 and settled  at               
,northumberland1 where he died on       
,february #fth1 #ahjd1 in the           
seventy-first year of his age4          
,illustration3 ,from a drawing by       
,alexander in the ,print ,room of the   
,british ,museum4    ,henry ,cavendish  
was born at ,nice in #agca1 and died in 
,london in #ahaj4  ,he was a natural    
philosopher in the widest sense of that 
term1 and  occupied himself in turn with
 nearly every branch of physical        
science4  ,he was a capable astronomer  
and an excellent mathematician1 and he  
was one of the earliest to work on the  
subject of specific heat1 and  to       

improve the thermometer and the methods 
of making thermometric  observations4   
,he also determined the mean density of 
the earth4 ,he made  accurate           
observations on the properties of       
carbonic acid and hydrogen1  greatly    
improved the methods of eudiometry1 and 
first established  the practical        
uniformity of the composition of        
atmospheric air4 ,his  greatest         
discovery1 however1 was his             
determination of the composition  of    
water4 ,he was the first to prove that  
water is not a simple or  elementary    
substance1 as supposed by the ancients1 
but is a compound of  hydrogen and      
oxygen4 ,in certain of his trials he    
found that the water  formed by the     
union of oxygen and hydrogen was acid to
 the taste2 and  the search for the     
cause of this acidity led him to the    
discovery of  the composition of nitric 
acid4 ,he was the first to make a fairly
  accurate analysis of a natural water1 
and to explain what is known as  the    

hardness of water4    ,phlogistonism may
 be said to have dominated chemistry    
during  three-fourths of the eighteenth 
century4 ,although radically false  as a
 conception and of little use in the    
true interpretation of  chemical        
phenomena1 it cannot be said to have    
actually retarded the  pursuit of       
chemistry4 ,men went on working and     
accumulating chemical  facts uninspired 
and1 for the most part1 uninfluenced by 
it4 ,even  ,priestley1 perhaps one of   
the most conservative of the followers  
of  ,stahl1 regarded his dogma with a   
complacent tolerance2 and as its        
inconsistencies became apparent he was  
more than once on the point  of         
renouncing it4 ,of one thing he was     
quite convinced1 and that was  that     
,stahl had greatly erred in his         
conception of the real nature of        
phlogiston4 ,perhaps the most signal    
disservice which phlogiston did to      
chemistry was to delay the general      
recognition of ,boyle's views of the    

nature of the elements4 ,the alchemists1
 it will be remembered1 regarded  the   
metals as essentially compound4 ,boyle  
was disposed to believe that  they were 
simple4 ,becher and ,stahl and their    
followers1 until the last  quarter of   
the eighteenth century1 also regarded   
them as compounds1  phlogiston being one
 of their constituents4 ,on the other   
hand1 what  we now know to be           
compounds--such as the calces1 the      
acids1 and water  itself--were held by  
the phlogistians to be simple           
substances4    ,the discovery1 in #aggd1
 of oxygen--the dephlogisticated air of 
,priestley--and the recognition of the  
part it plays in the phenomena  which   
phlogiston was invoked to explain1 mark 
the termination of one  era in chemical 
history and the beginning of another4   
,before entering  upon an account of the
 new era it is desirable to take stock  
of the  actual condition of chemical    
knowledge at the end of the phlogistic  
period1 and to show what advances had   

been made in pure and applied  chemistry
 during that time4    ,during the       
eighteenth century greater insight was  
gained into the  operations of the form 
of energy with which chemistry is mainly
  concerned1 and views concerning       
chemical affinity and its causes  began 
to assume more definite shape1 chiefly  
owing to the labours of  ,boerhaave1    
,bergman1 ,geoffroy1 and ,rouelle4 ,it  
was clearly recognised  that the large  
group of substances comprised under the 
term 8salts0  were compound1 and made up
 of two contrasted and1 in a sense1     
antagonistic constituents1 classed      
generically as acids and bases4    ,on  
the practical side chemistry made       
considerable progress4 ,analysis--a     
term originally applied by              
,boyle--greatly advanced4 ,it was1 of   
course1  mainly qualitative2 but1 thanks
 to the labours of ,boyle1 ,hoffmann1   
,marggraf1 ,scheele1 ,bergman1 ,gahn1   
and ,cronstedt1 certain reactions  and  
reagents came to be systematically      

applied to the recognition of  chemical 
substances1 and the precision with which
 these reagents were  used led to the   
detection of hitherto unknown elements4 
,the beginnings  of a quantitative      
analysis were made even before the time 
of ,boyle1  but its principles were     
greatly developed by him1 and were      
further  extended by ,homberg1          
,marggraf1 and ,bergman4 ,marggraf      
accurately  determined the amount of    
silver chloride formed by adding common 
salt  to a solution of a known weight of
 silver1 and ,bergman first pointed  out
 that estimations of substances might be
 conveniently made by  weighing them in 
the form of suitably prepared compounds1
 which1 it  was implicitly assumed1 were
 of uniform and constant composition4   
,the  foundations of an accurate system 
of gaseous analysis were made by        
,cavendish2 and various forms of        
physical apparatus were applied to the  
service of chemistry4    ,to the        
elements which were known prior to      

,boyle's time1 although not  recognised 
as such1 there were added phosphorus    
7,brand1 #affi71 nitrogen               
7,rutherford71 chlorine 7,scheele1      
#aggd71 manganese 7,gahn1 #aggd71 cobalt
  7,brandt1 #agdb71 nickel 7,cronstedt1 
#agej71 and platinum 7,watson1 #agej74  
,baryta was discovered by ,scheele1 and 
strontia by ,crawford4 ,phosphoric  acid
 was discovered by ,boyle1 and its true 
nature determined by  ,marggraf2        
,cavendish first made known the         
composition of nitric acid4  ,as already
 stated1 ,scheele first isolated        
molybdic and tungstic acids  and        
determined the existence of a number of 
the organic acids 7p4 #ge74  ,other     
discoveries--such as the true nature of 
limestone and magnesia  alba and their  
relations respectively to lime and      
magnesia by ,black1  the many gaseous   
substances by ,priestley1 and the       
compound nature of  water by            
,cavendish--have already been referred  
to4    ,technical chemistry also greatly

 developed during the eighteenth        
century1 thanks to the efforts of ,gahn1
 ,marggraf1 ,duhamel1 ,reaumur1         
,macquer1 ,kunkel1 and ,hellot2 and many
 important industrial  processes--such  
as the manufacture of sulphuric acid by 
,ward of  ,richmond1 and subsequently by
 ,roebuck at ,birmingham1 and the       
,leblanc  process of conversion of      
common salt into alkali--had their      
origin  during this period4             
,,chapter ,,viii    ,,lavoisier ,,and   
,,la ,r,,volution ,,chimique      ,we   
have seen how chemistry made a new      
departure during the political  upheaval
 which occurred in this country about   
the middle of the  seventeenth century4 
,it acquired a new impetus and took a   
fresh course  during the political      
cataclysm which overwhelmed ,france and 
alarmed  ,europe towards the close of   
the eighteenth century4 ,the instigator 
and leader of this second revolution in 
chemistry was ,lavoisier1 one  of the   
most distinguished men of his age1 and  

himself a victim of the  political fury 
of his own people4    ,antoine-,laurent 
,lavoisier was born in ,paris in #agdc4 
,at the ,jardin  du ,roi he came under  
the influence of ,rouelle1 one of the   
best  teachers of his time1 who         
eventually shaped his career as a       
chemist4  ,in #agfe he sent to the      
,academy his first paper on gypsum1     
which is  noteworthy as giving for the  
first time the true explanation of the  
8setting0 of plaster of ,paris1 and the 
reason why overburnt gypsum  will not   
rehydrate4 ,three years later he became 
a member of the  ,ferme-gnral--a company
 of financiers to whom the ,state       
conceded1 for  a fixed annual sum1 the  
right of collecting the indirect taxes  
of the  country4 ,it was this connection
 that brought ,lavoisier to the scaffold
  during the revolution of #agid4 ,like 
,stahl1 ,lavoisier discovered no new    
substance2 but1 also like ,stahl1 he    
created a new epoch by destroying  the  
philosophical system which ,stahl had   

established4    ,it is commonly stated  
that the exception is a proof of the    
rule4 ,the  history of science can show 
many instances whereby the rule has been
  demolished by the exception4 ,little  
facts have killed big theories1  even as
 a pebble has slain a giant4 ,during the
 reign of phlogiston  a few of such     
facts were not unknown--at least to some
 of the better  informed of ,stahl's    
followers4    ,some of the alchemists   
had discovered that a metal gained1 not 
lost1  weight by calcination4 ,this was 
known as far back as the sixteenth      
century4 ,it had been pointed out by    
,cardan and by ,libavius4 ,sulzbach     
showed that such was the case with      
mercury4 ,boyle proved it in the case   
of tin1 and ,rey in that of lead4       
,moreover1 as knowledge increased it    
became certain that ,stahl's original   
conception of the principle of          
combustion as a ponderable substance--he
 imagined1 with ,becher1 that it  was of
 the nature of an earth--was not        

tenable4 ,the later phlogistians  were  
disposed to regard it as probably       
identical with hydrogen4 ,but  even     
hydrogen has weight1 and facts seemed to
 require that phlogiston1  if it existed
 at all1 should be devoid of weight4    
,towards the latter half of the         
eighteenth century clearer views  began 
to be held concerning the relations of  
atmospheric air to the  phenomena of    
combustion and of calcination2 many     
half-forgotten facts  relating to these 
phenomena were recalled1 and the        
inconsistencies  and insufficiency of   
phlogiston as a dogma became gradually  
manifest4  ,three cardinal facts        
conspired to bring about its            
overthrow--the  isolation of oxygen by  
,priestley2 the recognition by him of   
the nature  of atmospheric air1 and of  
the fact that one of its constituents   
is oxygen2 and1 lastly1 the discovery by
 ,cavendish that water is a  compound1  
and that its constituents are oxygen and
 hydrogen4 ,the  significance of these  

facts was first clearly grasped by      
,lavoisier1 and  to him is due the      
credit of their true interpretation4 ,by
 reasoning  and experiment he proved    
conclusively that all ordinary phenomena
 of  burning are so many instances of   
the combination of the oxygen of the    
air with the combustible substance2 that
 calcination is a process of            
combination of the oxygen in the air    
with the metal1 which thereby  increases
 in weight by the amount of oxygen      
combined4 ,water--no longer a  simple   
substance--is formed by the union1      
weight for weight1 of oxygen  and       
hydrogen4 ,lavoisier's reasoning was so 
sound and his experimental  evidence so 
complete that his views gradually gained
 acceptance in  ,france4 ,the phlogiston
 myth was thus exploded4 ,inspired by   
,lavoisier1  a small band of ,french    
chemists--,berthollet1 ,fourcroy1       
,guyton de  ,morveau--thereupon set to  
work to remodel the system of chemistry 
and to recast its nomenclature so as to 

eliminate all reference  to phlogiston4 
,the very names 8oxygen10 8hydrogen10   
8nitrogen10  corresponding respectively 
to the 8dephlogisticated air10          
8phlogiston10  and 8phlogisticated air0 
of ,priestley1 were coined by the new   
,french  school4 ,for a time le principe
 oxygine was regarded by this school  in
 much the same relation as phlogiston   
was regarded by ,stahl and his          
followers4 ,the one fetich was exchanged
 for the other4 ,the combustible        
principle--phlogiston--was renounced for
 the acidifying principle--oxygen4  ,the
 new chemistry for a time centred itself
 round oxygen1 just as  the old         
chemistry had centred itself round      
phlogiston4 ,the views of  the ,french  
school met with no immediate acceptance 
in ,germany1 the  home of phlogistonism1
 or in ,sweden or ,england1 possibly    
owing1 to  some extent1 to national     
prejudices4 ,the spirit of revolution1  
even  although it might be an           
intellectual revolution1 had not        

extended to  these countries4           
,priestley1 ,cavendish1 and ,scheele    
could not be induced  to accept the new 
doctrine4 ,it was1 however1 accepted by 
,black1 and  its principles taught by   
him in ,edinburgh2 and before the end of
 the  century it had practically        
supplanted phlogistonism in this        
country4  ,some of those who1 like      
,kirwan1 had energetically opposed the  
new  theory ended by enthusiastically   
embracing it4 ,its introduction into    
,germany was mainly due to the influence
 of ,klaproth4    ,we further owe to    
,lavoisier the recognition of the       
principle which lies  at the basis of   
chemical science--the principle of the  
conservation of  matter4 ,lavoisier was 
not the first to introduce the use of   
the balance  into chemistry3            
quantitative chemistry did not actually 
originate with  him4 ,boyle1 ,black1 and
 ,cavendish1 as a matter of fact1       
preceded him in  recognising the        
importance of studying the quantitative 

relations of  substances4 ,nevertheless1
 no one before him so clearly           
foreshadowed the  doctrine of the       
indestructibility of matter1 and it was 
mainly through  his teaching that the   
balance came to be recognised as        
indispensable to  the pursuit of        
chemistry4 ,before his untimely death he
 had succeeded  in impressing upon the  
science the main features which at      
present  characterise it4    ,lavoisier 
was one of the most distinguished men of
 his age1 and his  merits as a          
philosopher were recognised throughout  
,europe4 ,indeed1  it is not too much to
 say that at the time of his death he   
was the  dominant figure in the chemical
 world of the eighteenth century4  ,in  
addition to his position as a member of 
the ,ferme-gnral he  was made by ,turgot
 a commissioner of the ,rgie des        
,poudres2 and  in this capacity he      
effected improvements in the manufacture
 and  refining of saltpetre1 and greatly
 increased the ballistic properties  of 

gunpowder4 ,he became ,secretary of the 
,committee of ,agriculture1  and drew up
 reports on the cultivation of flax1 of 
the potato1 and  on the liming of wheat2
 he prepared a scheme for the           
establishment  of experimental farms1   
and for the collection and distribution 
of  agricultural implements4 ,he        
introduced the cultivation of the beet  
root  in the ,blesois1 and improved the 
breed of sheep by the importation of    
rams and ewes from ,spain4 ,he was      
successively member of the ,assembly  of
 the ,orlanais1 ,dput supplant of the   
,states-,general1 and of  the ,commune  
of ,paris4 ,in #agia he was named       
,secretary and ,treasurer of  the famous
 ,commission of ,weights and ,measures1 
out of which grew the  international    
system1 based theoretically on a natural
 unit1 known as  the metric system1 and 
now adopted by most civilised countries 
in the  world4 ,he was not only the     
administrative officer of the           
,commission3  he contributed to the     

nomenclature of the system1 and directed
 the  determination of the physical     
constants on which the measurements     
rested1 and especially the determination
 of the weight of the unit  volume of   
water on which the value of the standard
 of mass was based4  ,lastly he was     
,treasurer of the ,french ,academy until
 its suppression in  #agic by the       
,convention1 which shortly afterwards   
ordered the arrest  of ,lavoisier and   
others of the                           
,fermiers-gnraux--twenty-eight in all4  
,they were sentenced to be executed     
within twenty-four hours1 and their     
property confiscated4 ,coffinhal1 who   
pronounced their doom1 declared3  8,la  
republique n'a pas besoin de savants40  
,thus in the fifty-first  year of his   
age1 perished the creator of modern     
chemistry--a victim to  the senseless1  
sanguinary fury of the 8,friends of the 
,people40 ,his  rectitude1 his public   
services1 the purity of his private     
life1 the  splendour of his scientific  

achievements--all were unheeded4 ,as    
,lagrange  said to ,delambre3 8,it      
required but a moment to strike off this
 head2 a  hundred years may not suffice 
to reproduce such another40             
,illustration3 ,,lavoisier ,,and        
,,berthollet    in the ,laboratory of   
the ,sorbonne1 ,paris4    ,of the men   
who were associated with ,lavoisier in  
the creation of what  was known at the  
period as the antiphlogistic chemistry1 
the most  eminent was ,berthollet4      
,claude-,louis ,berthollet was born in  
,savoy in #agdh1 and1 after a  medical  
education1 became physician to the ,duke
 of ,orleans4 ,devoting  himself to     
chemistry1 in #agha he was made a member
 of the ,academy1  and he became        
,government ,commissary and ,director of
 the ,gobelins1  the chief tinctorial   
establishment of ,france4 ,although in  
the main  in agreement with ,lavoisier1 
he never wholly subscribed to the idea  
that all acids contained oxygen4 ,he    
discovered the bleaching power of       

chlorine1 prepared potassium chlorate1  
and investigated prussic acid  and      
fulminating silver4    ,in his ,statique
 ,chimique1 published in #ahjc1 he      
combated the  partial and imperfect     
views of ,bergman and ,geoffroy with    
regard to  the operation of chemical    
affinity1 and showed that the direction 
of a chemical change is modified by the 
relative proportion of the  reacting    
substances and the physical             
conditions--temperature1 pressure1      
etc4--under which the change is         
effected4 ,he was one of the first to   
draw attention to a class of phenomena  
known as reversible reactions1  and gave
 a number of instances of their         
occurrence4 ,berthollet  pushed his     
conclusions so far that he was led to   
doubt that chemical  combination took   
place in fixed and definite proportions2
 and his views  gave rise to a memorable
 controversy between him and ,proust1 in
 which  the latter eventually triumphed4
    ,berthollet enjoyed a great         

reputation in his time1 and played a    
considerable part in the political      
history of his country4 ,it was  largely
 to his zeal1 sagacity1 and skill in    
developing her internal  resources at a 
critical period when she was hemmed     
round by foreign  troops and her ports  
blockaded by ,british ships1 that       
,france was  saved from conquest4 ,his  
life was more than once in jeopardy when
  ,france was governed by a ,committee  
of ,public ,safety2 but his honesty1    
sincerity1 and courage even impressed   
,robespierre1 and he escaped the  perils
 of the ,great ,terror4 ,he was an      
intimate friend of ,napoleon1  and      
accompanied him to ,egypt as a member of
 the ,institute4 ,he died at  ,arcueil  
in #ahbb4    ,davy1 who visited him at  
his country house in #ahac1 says of     
him3--      ,berthollet was a most      
amiable man2 when the friend of         
,napoleon1    even1 always good1        
conciliatory1 and modest1 frank and     
candid4    ,he had no airs1 and many    

graces4 ,in every way below ,la ,place  
in intellectual powers1 he appeared     
superior to him in moral    qualities4  
,berthollet had no appearance of a man  
of genius2 but one    could not look on 
,la ,place's physiognomy without being  
convinced    that he was a very         
extraordinary man4    ,other notable men
 of this period were ,fourcroy1         
,vauquelin1 ,klaproth1  and ,proust4    
,antoine-,franois ,fourcroy1 the son of 
a pharmacist1 was born at ,paris  in    
#agee1 and started his career as a      
dramatic author4 ,on the advice  of     
,vicq d',azir1 the anatomist1 he turned 
to medicine1 and in #aghd1 by  the      
influence of ,buffon1 obtained the chair
 of ,chemistry at the ,jardin  du ,roi1 
in succession to ,macquer4 ,he was an   
excellent teacher--clear1  orderly1 and 
methodical4 ,he had1 indeed1 a talent   
for oratory4 ,this he  assiduously      
cultivated1 and became one of the most  
popular lecturers of  his time in       
,france4 ,ambitious and time-serving1 he

 became embroiled in  the turbulent     
politics of the period1 and1 after a    
chequered career1  died1 embittered and 
disappointed1 in the fifty-fourth year  
of his  age4 ,his chief services to     
science consisted in his works1 ,systme 
des ,connaissances ,chimiques and       
,philosophie ,chimique4 ,these1 no  less
 than his public lectures1 did much to  
popularise the doctrines of  ,lavoisier 
among his countrymen4    ,louis ,nicolas
 ,vauquelin1 the son of a ,norman       
peasant1 was born in  #agfc1 and while a
 boy became assistant to an apothecary  
in ,rouen4 ,in  #aghj he came to ,paris1
 and entered ,fourcroy's laboratory4    
,much of the  experimental work         
published in ,fourcroy's name was       
actually done by  ,vauquelin4 ,he became
 a member of the ,academy in #agia1     
,professor of  ,chemistry at the ,mining
 ,school1 ,assayer to the ,mint1 and    
subsequently  ,professor of ,chemistry  
at the ,jardin des ,plantes4 ,on        
,fourcroy's  death he was made          

,professor of ,chemistry of the ,medical
 ,faculty of  ,paris4 ,vauquelin was no 
theorist2 he was1 however1 an excellent 
practical chemist1 and one of the best  
analysts of the period4 ,he  made a     
large number of mineral analyses1 more  
particularly for ,hauy1  the            
crystallographer4 ,he discovered the    
element chromium in the  so-called      
red-lead ore 7lead chromate7 from       
,siberia4 ,he also first made  known the
 existence of glucinum in beryl4 ,he    
described a method of  separating the   
platinum metals1 and worked upon iridium
 and osmium4  ,he investigated the      
hyposulphites1 cyanates1 and malates4   
,he  discovered the presence of benzoic 
acid in the urine of animals2 with      
,robiqet1 he first isolated asparagin2  
with ,buniva1 allantoic acid2  and with 
,bouillon de la ,grange1 camphoric acid4
    ,vauquelin lived wholly for science1
 and had no other interests  than in his
 laboratory4 ,he was pensioned in #ahbb1
 and died at his  birthplace--,st4 ,andr

 d',hberlot--in the sixty-sixth year of 
his age4    ,martin ,heinrich ,klaproth1
 born in #agdc at ,wernigerode1 in the  
,hartz1 began life1 like ,vauquelin1 as 
an apothecary's apprentice at           
,quedlinburg4 ,thence he went to        
,hanover1 and ultimately to ,berlin1    
where he studied under ,pott and        
,marggraf and entered the pharmacy of   
,valentine ,rose1 father of ,heinrich   
,rose1 the distinguished chemist1  and  
,gustav ,rose1 the mineralogist4 ,in    
#aghh he became a member of the  ,berlin
 ,academy1 and1 on the creation of the  
,berlin ,university in #ahji1  was made 
,professor of ,chemistry4 ,as already   
stated1 he was the first  chemist of    
eminence in ,germany to adopt the       
antiphlogistic theory4 ,he  was         
distinguished as an analyst4 ,he        
discovered tellurium1 analysed          
pitchblende and uranit1 and first made  
known the existence of  uranium1        
zirconium1 and cerium1 which he termed  
8ochroita40 ,he  analysed corundum1 and 

was an independent discoverer of        
titanium  and glucinum1 termed by him   
beryllium4 ,he made a large number of   
analyses of minerals1 such as leucite1  
chrysoberyl1 hyacinth1 granite1  olivin1
 wolfram1 malachite1 pyromorphite1 etc4 
,he continued actively at  work until   
his death1 in the seventy-fourth year of
 his age4    ,analytical chemistry is   
under great obligations to ,klaproth4   
,he  established a standard of accuracy 
never before approached2 and much  of   
his analytical work1 both as regards    
processes and results1 is of  permanent 
value4    ,joseph ,louis ,proust1 the   
son of a pharmacist was born at ,angers 
in  #agfa4 ,he received his early       
training in chemistry from his father1  
and1 after studying under ,rouelle in   
,paris1 obtained an appointment  at the 
,salpetrire4 ,proust has the credit of  
being the first chemist  to make a      
balloon ascent--in a ,montgolfier       
balloon with ,pilatre de  ,rozier4 ,on  
the invitation of the ,king of ,spain1  

he went to that  country to superintend 
certain chemical manufacturing          
processes4 ,he  became ,professor of    
,chemistry at the ,university of        
,salamanca1 and  subsequently went to   
,madrid1 where he was installed in a    
well-equipped  laboratory to enable him 
to examine the mineral riches of ,spain4
 ,on  the breaking out of war his work  
was interrupted1 and he was obliged  to 
leave ,madrid4 ,his laboratory was      
completely destroyed1 and his  valuable 
collection of apparatus and specimens   
dissipated4 ,through the  good offices  
of ,berthollet1 ,proust was offered a   
considerable sum of  money by ,napoleon 
in order to induce him to turn his      
discovery of grape  sugar to practical  
account4 ,proust was1 however1 too      
broken in health  to undertake the work 
of a factory manager1 and he retired to 
,mayence4  ,on the restoration of the   
,monarchy he was made a member of the   
,french  ,academy1 his honorarium as an 
,academician being augmented by a       

pension  from ,louis ,,xviii4 ,he died  
in #ahbf1 while on a visit to ,angers1  
his  native place4    ,proust is the    
discoverer of what is now styled 8the   
law of constant  proportion10 which     
states that the same body is invariably 
composed  of the same elements1 united  
in the same proportion4 ,he was a       
skilful  analyst1 and made numerous     
analyses of minerals2 and he was one of 
the  earliest to undertake a systematic 
study of metallic salts of organic      
acids4          ,,chapter ,,ix    ,,the 
,,atomic ,,theory      ,the opening     
years of the nineteenth century were    
made memorable by the  promulgation of  
the atomic theory by ,john ,dalton4 ,the
 enunciation of  this theory1 which     
affords a simple and adequate           
explanation of the  fundamental laws of 
chemical combination1 marks an epoch in 
the history  of chemistry4    ,it may be
 desirable to trace1 as briefly as      
possible1 the successive  steps which   
led up to the generalisation which more 

than any other  has served to stamp     
chemistry as an exact science4 ,that    
matter was  discrete--that is1 that it  
was not continuous1 but was composed of 
ultimate particles--was1 as already     
stated1 imagined by the ancients1  and  
was part of the philosophy of           
,leukippus1 ,demokritus1 and            
,leucretius4 ,but this supposition1     
although favoured by ,newton and other  
thinkers1 had little or no scientific   
basis prior to the middle of the        
eighteenth century4 ,from that time     
onward a variety of chemical facts      
gradually accumulated1 many of which at 
the time of their discovery  had no     
obvious connection with pre-existing    
facts4 ,it was reserved for  ,dalton to 
point out how an extension and more     
precise definition of  the old doctrine 
would suffice to connect and explain    
them4    ,the first germ of an atomic   
theory based on chemical fact may be    
traced  in the observation of ,toburn   
,bergmann 7b4 #agce1 d4 #aghd71         

,professor  of ,chemistry at ,upsala1   
that neutral solutions of certain metals
 in  contact with other metals gave a   
precipitate without the neutrality of   
the solution being disturbed1 and       
without gas being evolved4 ,one metal   
had simply replaced the other in        
solution4 ,bergmann thus incidentally   
discovered the fact of the chemical     
equivalence of metals4 ,he was  of      
opinion1 however1 that the phenomenon   
meant a transference of  phlogiston from
 one metal to another1 and that the     
process might be  made a mode of        
determining the relative amount of      
phlogiston in various  metals4          
,lavoisier extended ,bergmann's         
observations1 and sought to show1  in   
effect1 that the process afforded a     
means of determining the amounts  of the
 several metals which combined with one 
and the same quantity  of oxygen4 ,but  
neither ,bergmann nor ,lavoisier really 
grasped the idea  of equivalence as we  
understand it to-day4 ,it began to be   

appreciated  as the result of the work  
of ,jeremiah ,benjamin ,richter 7b4     
#agfb1  d4 #ahjg7 and of ,g4 ,e4        
,fischer on the mutual action of salts  
in  solutions1 and on the determinations
 of the amounts of acid and bases  which
 respectively combine with one another4 
,methods of measurement of  the         
proportions in which substances combine 
were grouped by ,richter  under the term
 ,stochiometry4    ,however desirable it
 may be in the interests of history to  
indicate  the sequence of the surmises  
and facts which preceded the formulation
  of the atomic theory1 it is very      
doubtful whether ,dalton was1 to any    
material extent1 influenced by them4 ,a 
self-educated man of lowly  origin1     
sturdily independent and highly         
original1 he was accustomed  to rely    
upon his own faculty of observation and 
experiment for his  facts1 and upon his 
own intellectual powers and mental      
energy for their  interpretation4       
,john ,dalton1 the son of a ,quaker     

hand-loom weaver1 was born at           
,eaglesfield1 in ,cumberland1 in #agff4 
,while still a boy he took to           
school-teaching1 and acquired1 in his   
leisure and by his own exertions1  a    
competent knowledge of mathematics and  
physical science4 ,in #agic he  was     
called to give instruction in           
mathematics1 natural philosophy1 and    
chemistry at the ,manchester ,new       
,college1 the ,nonconformist            
academy--now  moved from ,warrington--in
 which ,priestley had formerly lectured4
 ,here  he remained six years1 leaving  
the college to take up an independent   
position as a private tutor1 so as to   
enable him the more freely to  pursue   
his scientific inquiries4 ,in #ahjj he  
became ,secretary of the  ,philosophical
 ,society of ,manchester1 and remained  
connected1 as an  official1 with that   
institution until his death in #ahdd4   
,the greater  number of his scientific  
communications were published by that   
society4  ,in the outset of his         

scientific career he was attracted to   
meteorology2  and it was probably its   
problems which led him in the first     
place to  experiment1 and to speculate  
on the physical constitution of gases4  
,in the course of these observations he 
was led to the discovery  of the law of 
thermal expansion of gases1 with which  
his name is  now generally associated4  
,his speculations concerning the        
physical  constitution of gaseous       
substances1 arising from the            
contemplation of  gaseous phenomena1 led
 him to the conception that a gas is    
composed  of particles that repel one   
another with a force decreasing as the  
distance of their centres from each     
other2 and it is probable that in  this 
manner he familiarised himself with the 
idea of the existence of  atoms4 ,his   
first insight into the laws of the      
chemical combination of  these atoms    
seems to have originated from his       
discovery that1 when  two substances    
unite in different proportions1 these   

proportions may  be expressed in simple 
multiples of whole numbers4 ,thus he    
found1  on examining the composition of 
marsh gas and of ethylene1 both         
hydrocarbons1 that for the same weight  
of hydrogen there was twice the  amount 
of carbon in ethylene that there was in 
marsh gas4 ,he then  examined the oxides
 of nitrogen1 and found a similar       
regularity to  hold good in these       
compounds4 ,some time prior to the      
autumn of #ahjc  ,dalton was led to the 
supposition that these regularities     
could be  satisfactorily explained by   
the assumption that matter is composed  
of atoms having sizes and weights       
differing with each substance1 but  of  
identical weight and size for any       
particular substance1 and that  chemical
 combination consists in the            
approximation of these atoms4 ,this     
simple hypothesis explained all the     
facts then known4 ,it explained the     
constancy in the chemical composition of
 substances1 which may be said  to have 

been established by ,proust1 and which  
is now formulated as the  ,law of       
,constant ,proportion--that the same    
body is invariably composed  of the same
 elements1 united in the same           
proportion4 ,it explained also  the fact
 discovered by ,dalton that1 when an    
element unites with another  in         
different proportions1 the higher       
proportions are multiples of the        
lowest--now formulated as the ,law of   
,multiple ,proportion4 ,it further      
explained the fact1 which may be said to
 have been foreshadowed by  ,richter1   
that when two bodies1 ,a and ,b1        
separately combine with a third  body1  
,c1 the proportions of ,a and ,b which  
unite with ,c are measures or  multiples
 of the proportions in which ,a and ,b  
combine together4 ,this  is known as the
 ,law of ,reciprocal ,proportion4       
,illustration3 ,,john ,,dalton4    ,from
 a painting by ,b4 ,r4 ,faulkner in the 
possession of the ,royal  ,society      
,dalton's theory was first made         

generally known by ,thomas ,thomson1 in 
the third edition of his ,system of     
,chemistry1 published in #ahjg1 and  was
 employed by ,thomson in his paper on   
8,the ,oxalates of ,strontium10         
published the same year in the          
,philosophical ,transactions4 ,the first
  printed account by ,dalton himself is 
contained in ,part ,i4 of his ,new      
,system of ,chemical ,philosophy1       
published in #ahjh1 the substance of    
which had been previously given in a    
course of lectures at the ,royal        
,institution1 ,london1 and subsequently 
repeated in ,edinburgh and ,glasgow4    
,the statement of his theory is         
contained in chapter iii4 of this work1 
under the heading 8,of ,chemical        
,synthesis10 and is accompanied by a    
plate and explanation1 of which a       
facsimile is given on pp4 #acj-a4       
,the facts upon which ,dalton based his 
theory are incontrovertible2 but        
,dalton's explanation of them was not   
universally accepted at the time  he    

gave it4 ,davy1 who1 of course1 was     
familiar with the conception  of atoms  
as part of the ,newtonian philosophy1   
objected to the term  8atomic weight0   
introduced by ,dalton1 and suggested the
 expression  8combining proportion02 and
 ,wollaston1 for similar reasons1       
proposed  the term 8equivalent10 as     
denoting the constant quantity with     
which  bodies went in and out of        
combination4 ,there is no doubt that the
 use  of these terms retarded the       
general acceptance of ,dalton's         
doctrine1  and1 moreover1 brought into  
the science a confusion which was not   
finally dispelled1 as we shall see1     
until during the second half of the     
century4    ,illustration3 ,,elements   
,simple    ,binary    ,ternary          
,quaternary    ,quinquenary  ,sextenary 
,septenary      ,the illustration on the
 preceding page contains the arbitrary  
marks    or signs chosen to represent   
the several chemical elements or        
ultimate particles4        ,fig4        

#a4 ,hydro4 its rel4 weight             
#a       #b4 ,azote                     
#e       #c4 ,carbone or charcoal       
#e       #d4 ,oxygen                    
#g       #e4 ,phosphorus                
#i       #f4 ,sulphur                   
#ac       #g4 ,magnesia                 
#bj       #h4 ,lime                     
#bc       #i4 ,soda                     
#bh      #aj4 ,potash                   
#db      #aa4 ,strontites               
#df      #ab4 ,barytes                  
#fh      #ac4 ,iron                     
#ch      #ad4 ,zinc                     
#ef      #ae4 ,copper                   
#ef      #af4 ,lead                     
#ie      #ag4 ,silver                   
#ajj      #ah4 ,platina                 
#ajj      #ai4 ,gold                    
#adj      #bj4 ,mercury                 
#afg      #ba4 ,an atom of water or     
steam1 composed of #a of                
oxygen and #a of hydrogen1 retained in  
physical            contact by a strong 
affinity1 and supposed            to be 

surrounded by a common atmosphere       
of heat2 its relative weight            
#h      #bb4 ,an atom of ammonia1       
composed of #a of azote            and  
#a of hydrogen                          
#f      #bc4 ,an atom of nitrous gas1   
composed of #a of azote            and  
#a of oxygen                            
#ab      #bd4 ,an atom of olefiant gas1 
composed of #a of carbone            and
 #a of hydrogen                         
#f      #be4 ,an atom of carbonic oxide 
composed of #a of            carbone and
 #a of oxygen                           
#ab      #bf4 ,an atom of nitrous oxide1
 #b azote  #a oxygen            #ag     
#bg4 ,an atom of nitric acid1 #a azote  
#b oxygen              #ai      #bh4 ,an
 atom of carbonic acid1 #a carbone  #b  
oxygen                                  
#ai      #bi4 ,an atom of carburetted   
hydrogen1 #a carbone             #b     
hydrogen                                
#g      #cj4 ,an atom of oxynitric acid1
 #a azote  #c oxygen           #bf      

#ca4 ,an atom of sulphuric acid1 #a     
sulphur  #c oxygen         #cd      #cb4
 ,an atom of sulphuretted hydrogen1 #a  
sulphur             #c hydrogen         
#af      #cc4 ,an atom of alcohol1 #c   
carbone  #a hydrogen              #af   
#cd4 ,an atom of nitrous acid1 #a nitric
 acid  #a            nitrous gas        
#ca      #ce4 ,an atom of acetous acid1 
#b carbone  #b water            #bf     
#cf4 ,an atom of nitrate of ammonia1 #a 
nitric acid             #a ammonia  #a  
water                                   
#cc      #cg4 ,an atom of sugar1 #a     
alcohol  #a carbonic acid           #ce 
,dalton's estimations of the relative   
weights of the atoms1 or1 to use        
,davy's phrase1 the values of their     
combining proportions1 were1 as  might  
be expected1 very rough approximations  
to the truth4 ,this arose  partly from  
inadequate experimental data1 and partly
 from uncertainty  as to the relative   
number of the constituent atoms which   
made up a  compound4 ,neither ,dalton   

nor his immediate successors had any    
rational  or consistent method of       
determining the latter point4 ,the view 
taken of  the composition of the        
compound decided what particular        
multiples or  sub-multiples of the      
values of the atomic weights of its     
constituents  were to be adopted4 ,as   
,dalton1 in many cases1 had no real     
criterion to  guide him1 he made the    
simplest possible assumptions2 but these
 might  or might not be valid2 and      
subsequent experience showed that in    
some  cases they were erroneous4    ,it 
was1 however1 generally recognised that 
these atomic weights1  combining        
proportions1 or equivalents1 as they    
were for a time  indifferently termed1  
were chemical constants of the highest  
importance1 both to the scientific      
chemist1 who1 apart from their          
theoretic interest1 had need of them in 
the course of quantitative  analysis1   
and to the manufacturing chemist1 who   
required them for  the intelligent      

exercise of his operations2 and         
accordingly a number  of chemists1 very 
shortly after the promulgation of       
,dalton's theory1  attempted to         
determine their values with all possible
 precision4 ,chief  among these was the 
,swedish chemist ,berzelius1 to whom    
science was  indebted for a series of   
estimations of atomic weights1 which    
were long  regarded as models of        
quantitative accuracy1 and stamped their
 author  as the greatest master of      
determinative chemistry of his age4     
,jns ,jakob ,berzelius1 the son of a    
schoolmaster1 was born near  ,linkping1 
in ,east ,gothland1 ,sweden1 in #aggi4  
,entering ,upsala with  a view to the   
profession of medicine1 he was          
attracted1 under the  influence of      
,afzelius--or1 rather1 in spite of      
it--to the study of  chemistry1 and1    
later1 of voltaic electricity1 then in  
its infancy4  ,while holding a number of
 minor appointments as a teacher of     
medicine1  pharmacy1 physics1 and       

chemistry1 he was elected1 in #ahjh1 a  
member  of the ,swedish ,academy of     
,sciences1 of which he became ,president
 in  #ahaj4 ,in #ahah he was made       
permanent ,secretary of the ,academy1   
and1 by  means of a yearly subsidy1 was 
enabled to devote himself wholly to     
experimental science4 ,he was ennobled  
in #ahah1 and on the occasion of  his   
marriage1 in #ahce1 was created a baron 
of the ,scandinavian kingdom4  ,he died 
in #ahdh4    ,berzelius occupies a      
pre-eminent position in the history of  
chemistry1  and during a considerable   
portion of his lifetime exercised an    
almost  unassailable authority as a     
chemical philosopher4 ,he is            
distinguished  as an experimenter1 as a 
discoverer1 as a critic and interpreter1
  and as a lawgiver4 ,his contributions 
to chemical knowledge range  over every 
department of the science4 ,he shares   
with ,davy the honour  of having        
established the fundamental laws of     
electro-chemistry4  ,his experimental   

work on the atomic weights of the       
elements--the  great work of his        
life--was of supreme importance at this 
particular  period of the development of
 chemistry3 it served not only to give  
precision to1 and enhance the           
significance and value of1 ,dalton's    
generalisation1 but it furnished        
chemists1 for the first time1 with  a   
set of constants1 ascertained with the  
highest exactitude of which  operative  
chemistry was then capable1 thereby     
contributing to the  expansion of       
quantitative analysis1 and to a more    
exact knowledge of  the composition of  
substances4 ,berzelius1 indeed1 was an  
analyst of the  first                   
rank--conscientious1 patient1 and       
painstaking2 an ingenious and  skilful  
manipulator2 inventive and resourceful4 
,what determinative  chemistry owes to  
his labours1 and not less to his        
example1 is obvious  from even the most 
superficial examination of its          
literature during the  first third of   

the last century4    ,as a discoverer1  
,berzelius first made known the         
existence of cerium  7#ahjc71 of        
selenium 7#ahah71 and of thorium        
7#ahbh72 and he prepared  and           
investigated a large number of their    
combinations4 ,he isolated  silicon     
7#ahbc71 zirconium 7#ahbd71 tantalum    
7#ahbd71 and studied  the compounds of  
vanadium1 discovered by his countryman  
,sefstrm4  ,he largely extended our     
knowledge of groups of substances in    
which  sulphur replaces oxygen2         
investigated compounds of fluorine      
7#ahbd71  platinum 7#ahbh71 and         
tellurium 7#ahca-ahcc71 and made many   
analyses of  minerals1 meteorites1 and  
mineral-waters4 ,he discovered racemic  
acid  and investigated the              
ferrocyanides4 ,it was his investigation
 of racemic  acid--which has the same   
percentage composition as tartaric      
acid--that  first enabled him to grasp  
the conception of isomerism1 a term     
which  we owe to him1 and of metamerism 

and polymerism4 ,he was the first  to   
study the phenomena of contact-actions1 
which he comprehended under  the term   
catalysis4    ,illustration3 ,j,,ns     
,,jakob ,,berzelius4    ,from a painting
 by ,j4 ,g4 ,sandberg4    ,as an author 
his literary activity was astonishing4  
,his new system of  mineralogy marks an 
epoch in the history of that branch of  
science4 ,his  text-book on chemistry   
was long the leading manual1 and went   
through  many editions1 being constantly
 revised by him4 ,his annual reports on 
the progress of physics and chemistry   
extended to twenty-seven volumes  and   
constitute a monument to his industry1  
thoroughness1 perspicacity1  and        
critical ability4    ,although holding  
no university appointment1 and with a   
laboratory of  the most modest          
dimensions and character1 ,berzelius1   
exercised great  influence as a teacher4
 ,some of the most notable chemists of  
the last  century1 such as ,heinrich and
 ,gustav ,rose1 ,dulong1 ,mitscherlich1 

,whler1 ,chr4 ,gmelin1 and ,mosander1   
were among his pupils2 and many of  them
 have testified to his stimulating power
 as an investigator of  nature1 and to  
his merits as a worthy1 genial man4     
,the reasonableness of ,dalton's        
conjecture received further support     
from the discovery by ,gay ,lussac in   
#ahjh1 that gases always combine  in    
simple proportions by volume1 and that  
the volume of the gaseous  product      
formed1 when measured under comparable  
conditions of  temperature and pressure1
 stands in a simple relation to the     
volumes  of the constituents4 ,the law  
of pressure discovered by ,boyle1 that  
of thermal expansion by ,dalton1 and of 
volumes by ,gay ,lussac 7which1  it     
ought to be stated1 was previously and  
independently made by  ,dalton71 are    
explained on the assumption that equal  
numbers of the  particles--either as    
simple particles or as compound         
particles--are  present in the same     
volume of the gas4 ,this method of      

explanation was  first clearly stated by
 the ,italian physicist ,avogadro in    
#ahaa1 but  its significance1 as will be
 seen subsequently1 was not appreciated 
until half a century later4    ,as the  
values for the atomic weights gradually 
became more exact1  speculations arose  
as to the significance of the numerical 
relations  which were observed to exist 
among them4 ,in #ahae ,william ,prout   
threw  out the supposition that the     
atomic weights of the gaseous elements  
are multiples by whole numbers of that  
of hydrogen4 ,extended into a           
generalisation1 this might be held to   
indicate that all kinds of matter  are  
so many forms of a primordial substance4
 ,subsequent inquiry showed  that       
,prout's 8,law10 as it is sometimes     
called1 was not tenable in its  original
 form4 ,certain elements1 it was        
conclusively proved1 had atomic  weights
 which were not whole numbers4 ,dumas   
subsequently modified the  law1 after a 
redetermination of a large number of    

atomic weights1  by assuming that the   
substance common to the so-called       
elements had  a lower atomic weight than
 unity4 ,although there are a           
considerable  number of elements whose  
atomic weights1 based upon the most     
accurate determinations1 are remarkably 
close to whole numbers1 the             
investigations of ,stas and others      
afford no valid reason for believing    
that ,prout's hypothesis1 and the       
underlying supposition to which it has  
been held to point1 are justified by    
experimental evidence4                  
,,chapter ,x    ,,the ,,beginnings ,,of 
,,electro-,,chemistry      ,the first   
year of the nineteenth century is       
further memorable on  account of the    
invention of the voltaic pile1 and by   
reason of its  application by ,william  
,nicholson and ,sir ,anthony ,carlisle  
to the  electrolytic decomposition of   
water4 ,this mode of resolving water    
into  its constituents made a great     
sensation at the time1 mainly because   

of the extraordinary method by which it 
was effected4 ,it afforded an           
independent and unlooked-for proof of   
the compound nature of water  by a      
method altogether differing in principle
 from that by which its  composition had
 been previously ascertained4 ,the      
formation of water by  the combustion of
 hydrogen brought no conviction of its  
real nature  to a confirmed phlogistian 
like ,priestley2 and it is even doubtful
  whether ,cavendish ever fully realised
 the true significance of his  great    
discovery4 ,but the fact that the       
quantitative results of the  analysis   
thus effected were identical with those 
of its synthesis1 as  made by ,cavendish
 and ,lavoisier1 admitted of only one   
interpretation4  ,this cardinal         
discovery may be said to have completed 
the downfall of  phlogiston4    ,the    
value of the voltaic pile as an         
analytical agent was nowhere more       
quickly appreciated than in ,england4   
,in the hands of ,humphry ,davy its     

application to the analysis of the      
alkalis and alkaline earths led to      
discoveries of the greatest magnitude4  
,humphry ,davy was born in ,penzance in 
#aggh4 ,in the course of his  studies   
for the profession of medicine he was   
attracted to chemistry2  and he became  
chemical assistant to ,dr4 ,beddoes1 a  
former teacher of  chemistry at ,oxford1
 but then living at ,clifton1 near      
,bristol4 ,while  in the capacity of    
assistant and operator in ,beddoes's    
,pneumatical  ,institute1 ,davy         
discovered the intoxicating properties  
of nitrous  oxide 7so called laughing   
gas71 which brought him into prominence 
and led to his engagement by the        
managers of the newly-created ,royal    
,institution in ,london as lecturer in  
chemistry in succession to  ,garnett4   
,he early began to experiment on        
galvanism1 and soon succeeded  in       
developing the fundamental laws of      
electro-chemistry2 and in #ahjg he      
effected the decomposition of potash and

 soda by the application of  voltaic    
electricity--thereby establishing1 what 
indeed had been surmised  previously1   
that the alkalis are compound           
substances4 ,he subsequently  proved    
that this was also the case with the    
alkaline earths4 ,davy thus  added some 
five or six metallic elements to those  
already known4    ,these discoveries1   
perhaps the most brilliant of their     
time1 afforded  additional evidence of  
the invalidity of ,lavoisier's          
assumption that  oxygen1 as the name    
implies1 was the 8principle of acidity40
 ,the  surmise1 in fact1 was already    
disproved by the case of water--a       
neutral  substance and devoid of all the
 recognised attributes of an acid4 ,it  
was still further disproved by the cases
 of potash and soda--strongly  alkaline 
compounds4    ,additional evidence was  
adduced by ,davy in demonstrating1 in   
#ahaj1  that the so-called oxymuriatic  
acid1 the dephlogisticated  marine acid 
discovered by ,scheele1 contained no    

oxygen1 but was  a simple1 indivisible  
substance4 ,for the old designation1    
which  connoted a compound body1 he     
substituted the name chlorine1 in       
allusion to the characteristic colour of
 the element4 ,in the course  of his    
investigation on this substance he      
discovered the penta-  and trichloride  
of phosphorus1 chlorophosphamide and    
chlorine  peroxide4 ,he was also the    
discoverer of telluretted hydrogen and  
an  independent discoverer of           
nitrosulphonic acid4    ,illustration3  
,,sir ,,humphry ,,davy4    ,from a      
painting by ,lawrence in the possession 
of the ,royal ,society4    ,he worked on
 iodine and the iodates1 on the diamond1
 on the  so-called fuming liquor of     
,cadet1 on nitrogen chloride1 and on the
  pigments of the ancients4 ,lastly1 he 
invented the miner's safety  lamp1 with 
which his name will always be           
associated1 effecting thereby  what was 
practically a revolution in coal-mining4
 ,he became ,president  of the ,royal   

,society in #ahbj1 and died at ,geneva  
on ,may #bith1 #ahbi1 in  the           
fifty-first year of his age4 ,davy was a
 singularly gifted man1 of  great mental
 vigour and imaginative power2 quick1   
lively and ingenious2  an eloquent      
teacher and a daring and brilliant      
experimenter4    ,another noteworthy    
name in the chemical history of this    
period is  ,wollaston4 ,william ,hyde   
,wollaston1 born at ,east ,dereham1 in  
,norfolk1  in #agff1 was educated at    
,cambridge with a view to the profession
 of  medicine1 but1 failing to secure a 
practice1 he devoted himself to  the    
pursuit of science1 and especially to   
optics and chemistry4 ,he  devised a    
method of working platinum1 and was the 
first to make known  the existence of   
palladium and rhodium4 ,he was one of   
the most  ingenious and acute analysts  
of his time1 and possessed remarkable   
inventive powers4 ,he investigated the  
nature of urinary calculi  and chalk    
stones4 ,his paper on the oxalates of   

potash was of  great service at the time
 as a demonstration of the law of       
multiple  proportions4 ,he first drew   
attention to the existence in the solar 
spectrum of what were subsequently      
termed the ,fraunhofer lines2 and  he   
invented the reflecting goniometer and  
the camera lucida1 and  a slide rule for
 chemical calculations4 ,he resembled   
,cavendish in  temperament and mental   
habitudes1 and1 like him1 was           
distinguished  for the range and        
exactitude of his scientific knowledge1 
his habitual  caution1 and his cold and 
reserved disposition4 ,he died in #ahbh4
    ,illustration3 ,,william ,,hyde     
,,wollaston4    ,from a painting by ,j4 
,jackson1 ,r4,a41 in the possession of  
the ,royal  ,society4    ,almost        
immediately after the publication of    
,volta's discovery attempts  were       
made--notably by ,berzelius in ,sweden  
and by ,davy in ,england--to  prove that
 electrical and chemical phenomena are  
correlated and  mutually dependent4     

,this assumption was more fully worked  
out by  ,berzelius in #ahab1 and it     
served as the basis of a chemical system
  which exercised considerable influence
 on chemical doctrine during the  first 
half of the nineteenth century4         
,berzelius assumed that electric        
polarity was an attribute of all        
atoms--that these were bipolar1 in fact1
 but that in them either  positive or   
negative electricity predominated4      
,hence the elements  were capable of    
being divided into two classes--that is1
 positive or  negative1 depending upon  
the excess of either charge4 ,which of  
the  electricities predominated might be
 ascertained by determining the         
particular pole at which the element was
 separated on electrolysis4             
,combinations of dissimilar             
elements--or1 in other words1 chemical  
compounds--were also endowed with       
polarity4 ,the chemical affinities of   
elements and compounds were related to  
the excess of either kind of            

electricity resident in them2 and       
chemical combination resulted from1  and
 was a consequence of1 the more or less 
perfect neutralisation  of the two      
kinds4 ,from a study of the electrical  
deportment of the  elements ,berzelius  
sought to arrange them in series1       
starting with  oxygen as the most       
electro-negative member4    ,these      
conceptions were employed by him as the 
basis of a method of  classification4   
,the attempt is historically interesting
 as being the  first systematic         
endeavour to gain an insight into the   
constitution  of chemical               
compounds--that is1 to determine the    
manner in which the  constituent atoms  
are grouped or arranged with respect to 
one another1  or1 in other words1 to    
distinguish between the empirical and   
the  rational composition of substances1
 which is the ultimate aim of modern    
chemistry4    ,a necessary consequence  
of these views was that every compound  
was to  be considered as made up of two 

parts in electrically different states4 
,thus baryta1 consisted of a combination
 of the electro-positive barium1        
combined with the electro-negative      
oxygen2 it combined with sulphuric      
oxide because the preponderating        
positive electricity it contained met   
with the negative electricity which     
prevailed in the sulphuric oxide4       
,generalising1 it may be said that the  
basic oxides are invariably  the        
positive constituents of salts1 whereas 
the acid oxides are the  negative       
constituents1 as proved by the mode in  
which the two kinds of  oxides separated
 at the poles on electrolysis4 ,barium  
sulphate1 then1  was to be regarded as  
made up of two entities--,ba,o and      
,,so#c--;and hence was  to be called    
sulphate of baryta4 ,berzelius extended 
this conception  in order to explain the
 formation of double salts--such1 for   
example1  as potash alum1 which he      
regarded as a binary compound of        
positive  potassium sulphate and        

negative aluminium sulphate1 each of    
which1  in its turn1 could be resolved  
into an acidic and a basic oxide of     
opposite electricities4    ,the         
dualistic notions of ,berzelius led him 
to the construction of  a system of     
chemical nomenclature and notation      
which1 in its main  features1 has       
persisted to this day1 and is           
universally current1 with  certain      
modifications1 in modern chemical       
literature4 ,we owe to him  the grouping
 of the elements into metals and        
metalloids1 and also our  present system
 of symbolic notation1 whereby even     
complicated chemical  reactions may be  
expressed in a concise and intelligible 
manner4  ,chemical symbols were used by 
the alchemists2 but ,berzelius first    
suggested that a chemical symbol should 
not only represent the element  to which
 it refers1 but also its relative atomic
 weight4 ,chemical  equations became    
quantitative as well as qualitative     
expressions of  the facts they denote4  

,such equations implicitly assumed that1
 to  use ,davy's words1 chemistry had   
passed under the dominion of the        
mathematical sciences4 ,professed       
mathematicians were1 however1 slow to   
recognise that the phenomena of chemical
 action were capable of formal          
mathematical treatment4 ,davy relates   
that on speaking to ,laplace of  the    
atomic theory in chemistry1 and         
expressing his belief that the  science 
would ultimately be referred to         
mathematical laws similar to  those he  
had so profoundly and successfully      
established with respect  to the        
mechanical properties of matter1 the    
idea was treated in a tone  bordering on
 contempt4    ,berzelius's              
electro-chemical system1 and the        
dualistic ideas associated  with it1    
were of considerable service when       
applied to the inorganic  branch of the 
science2 but attempts to fit them to the
 facts of organic  chemistry1 which     
began to accumulate rapidly after the   

first quarter of  the century1 failed4  
,its inadequacy as a comprehensive      
generalisation  became more and more    
manifest1 and it eventually fell4 ,in   
fact1 it may  be said to have received  
its death-blow by ,davy's discovery of  
the  elementary nature of chlorine1 and 
by the recognition of the fact that  the
 acids do not necessarily contain       
oxygen4 ,davy and1 later1 ,dulong  made 
it obvious that1 if any one element was 
to be regarded as the  acidifying       
principle1 it was hydrogen1 and not     
oxygen2 and1 in a sense1  this view     
ultimately prevailed in the recognition 
of the acids as salts  of hydrogen4     
,in ,france the study of                
electro-chemistry was undertaken by ,gay
 ,lussac  and ,thnard1 largely owing to 
the action of the ,emperor ,napoleon1   
who furnished the funds for the         
construction of a powerful galvanic     
battery4 ,the results were published1 in
 #ahaa1 under the title1  ,recherches   
,physico-,chimiques1 faites sur la      

,pile1 etc4 ,gay ,lussac1  whose name   
has already been mentioned as one of the
 discoverers of  the ,law of            
,combination of ,gases1 played a        
considerable part in the  history of    
chemistry at this period4 ,he was one of
 the earliest to  appreciate the        
importance of ,dalton's generalisation1 
and to point  out the significance of   
his own discovery in strengthening it4  
,he was  probably led1 in the first     
instance1 to the recognition of the law 
of  gaseous combination by ,berthollet's
 work on the volumetric composition  of 
ammonia gas1 and by his own             
discovery--made in #ahje1 in conjunction
  with ,humboldt1 in the course of their
 analysis of atmospheric air--that  one 
volume of oxygen combined with exactly  
two volumes of hydrogen to  form water4 
,the regularities thus indicated he     
found to be general3 all  gases which   
are capable of chemical union combine in
 simple proportions  by volume1 and the 
volume of the product1 if a gas1 always 

stands in  some simple relation to the  
volumes of the constituents4    ,joseph 
,louis ,gay ,lussac was born in #aggh1  
at ,saint ,leonard1 studied  chemistry  
in ,paris1 and was associated in        
chemical inquiry with  ,berthollet4 ,as 
,eleve-,ingenieur in the cole ,nationale
 des ,ponts et  des ,chausses he began  
the experimental work in physics and    
chemistry  upon which his fame rests4   
,in #ahjd he undertook1 with ,biot1 a   
series  of balloon ascents for the      
purpose of investigating the physics and
  chemistry of the upper regions of the 
atmosphere4 ,in #ahjf he became         
,professor of ,chemistry at the cole    
,polytechnique1 and in #ahcb  ,professor
 at the ,jardin des ,plantes4 ,he was   
one of the chief assayers  of the       
,french ,mint1 and1 as member of many   
commissions1 exerted  considerable      
influence in official circles4 ,he died 
in #ahej4    ,gay ,lussac and ,thnard   
were the first to devise a method of    
obtaining  potassium and sodium by a    

purely chemical process1 whereby these  
metals could be procured in far larger  
quantities than was at that  time       
possible by electrolytic means4 ,they   
were thus enabled to make  use of the   
strong deoxidising power of these metals
 to effect a number  of reductions1     
notably that of boric oxide to boron4   
,gay ,lussac and  ,thnard were also the 
first to make known the existence of    
boron  fluoride4 ,we further owe to ,gay
 ,lussac the discovery of cyanogen1  the
 first of the so-called compound        
radicals4 ,he first prepared  ethyl     
iodide1 investigated sulphovinic acid   
and grape sugar1 studied  etherification
 and fermentation1 etc4 ,we are also    
indebted to him  for a method of        
determining vapour densities which      
proved of great  service in ascertaining
 the molecular weights of substances4   
,he worked  on iodine and its compounds1
 discovered1 with ,welter1 thiosulphuric
  acid1 and investigated fulminic acid  
in collaboration with ,liebig4    ,among

 his services to analytical chemistry   
were his method for the  analysis of    
gunpowder1 his volumetric estimation of 
silver 7wet silver  assay71 chlorometric
 analysis1 alkalimetry1 etc4 ,he devised
 the system  still in use in ,france for
 the estimation of alcohol in spirits of
 wine4    ,louis ,jacques ,thnard was   
born in #aggg at ,nogent-,sur-,seine1   
and was  a pupil of ,vauquelin and of   
,berthollet4 ,in #agig he became        
reptiteur  at the ,polytechnic ,school  
of ,paris1 and eventually its professor4
 ,he  subsequently occupied the chair of
 chemistry at the ,collge de ,france1   
and of the ,faculty of ,science of the  
,university of ,paris4 ,he was  ennobled
 by ,charles ,x4 in #ahbd1 and died at  
,paris in the eightieth year  of his    
age4    ,in addition to his work with   
,gay ,lussac already mentioned1 we owe  
to ,thnard the discovery of hydrogen    
peroxide and hydrogen  persulphide4     
,together with ,dulong he studied the   
catalytic action of  platinum on        

mixtures of oxygen and hydrogen4 ,he    
investigated the fatty  acids1 and      
worked on fermentation and on           
ether-formation2 and he was  the first  
to isolate citric and malic acids4 ,he  
also occupied himself  with the         
chemistry of bile1 perspiration1        
albumen1 the acids of urine  and milk1  
and with the theory of mordants4    ,in 
#ahcd ,faraday made known the important 
fact that on passing the same  galvanic 
current through a number of             
electrolytes--water1 hydrochloric  acid1
 solutions of metallic chloride--these  
were decomposed in such  manner that    
definite amounts of hydrogen or metal   
were separated at the  negative pole1   
and corresponding amounts of oxygen or  
chlorine were  evolved at the positive  
pole4 ,these observations were          
comprehended  by ,faraday under his 8law
 of definite electrolytic action40 ,the 
electro-chemical equivalents thus       
obtained were in some cases identical   
with the atomic weights deduced by      

,berzelius2 in others they were  not2   
but1 nevertheless1 when they differed1  
they stood in some simple  relation to  
the assumed atomic weight4 ,the         
significance of ,faraday's  observation 
was not lost sight of1 although his     
anticipation that the  determination of 
electro-chemical equivalents would be of
 use in fixing  atomic weights was not  
immediately appreciated4 ,a clear       
distinction  between the equivalent1 the
 atom1 and the molecule was not  then   
apprehended4 ,as will be subsequently   
shown1 it was only during  the latter   
half of the nineteenth century that the 
discrepancies and  inconsistencies thus 
revealed were definitely reconciled and 
cleared  up4          ,,chapter ,,xi    
,,the ,,foundations ,,of ,,organic      
,,chemistry      ,as the horizon of     
chemistry widened and its operations    
extended1 it  became necessary to treat 
its subject-matter methodically4        
,accordingly  attempts were made in the 
various systematic treatises which began

 to  appear in the seventeenth century  
to group its facts into an orderly  and 
rational arrangement4 ,one of the       
earliest of such systematic  treatises  
was the ,cours de ,chimie of ,nicolas   
,lemery1 published in  #afge4 ,although 
this work was styled by ,boerhaave 8a   
tumultuary mass of  pharmaceutical      
processes1 without any certain design or
 coherence10 it  is noteworthy as being 
the first of its kind to divide the     
science into  its present main branches 
of inorganic and organic chemistry4     
,it may be desirable to indicate1 as    
briefly as possible1 the general  state 
of knowledge respecting the chemistry of
 organic substances  down to the early  
years of the last century4 ,as already  
mentioned1  such substances as acetic   
acid1 turpentine1 starch1 sugar1 certain
  dye stuffs1 and oils1 had long been   
known2 and such processes as            
saponification and fermentation had been
 practised from very early  times4 ,the 
alchemists had prepared a variety of    

essential oils1  aliphatic ethers1 and  
esters2 and the iatro-chemists had      
obtained  benzoic and succinic acids1   
and acetic acid from wood4 ,milk sugar  
was first prepared by ,fabrizio         
,bartoletti in #afai4 ,grape sugar was  
first mentioned as occurring in honey by
 ,glauber in #affj4 ,boyle first        
detected the presence of a spirit among 
the products of the destructive         
distillation of wood4 ,few of the       
followers of ,stahl occupied themselves 
with organic products2 and it was only  
towards the end of the  phlogistic      
period that attention was once more     
directed to products of  animal and     
vegetable origin4 ,scheele isolated     
glycerin in #aghd1 and  obtained ethyl  
chloride by the distillation of a       
mixture of common  salt1 pyrolusite1 oil
 of vitriol1 and alcohol4 ,ethyl acetate
 was  first prepared by ,lauraquais in  
#agei4 ,arvidson obtained ethyl formate 
in #aggg4 ,oxalic ether was first made  
by ,savary in #aggc4 ,what was  long    

known as oil of wine appears to have    
been first mentioned by  ,libavius1 but 
its true nature was discovered by       
,hennel in #ahbf4 ,the  formation of    
aldehyde was first recognised by        
,scheele in #aggd1 and  it was in turn  
investigated by ,fourcroy and           
,vauquelin1 ,dbereiner1 and  ,gay       
,lussac2 but it was first definitely    
isolated in #ahce by ,liebig1 who  gave 
it its name4    ,the first organic acid 
known was vinegar 7acetic acid71 and for
 a  long time all naturally occurring   
organic acids having a sour taste  were 
regarded as identical with or as forms  
of vinegar4 ,it was only  during the    
second half of the eighteenth century   
that it was clearly  ascertained that a 
variety of organic acids exist1         
perfectly distinct  from acetic acid4   
,glacial acetic acid was first obtained 
by ,lwiz  in #aghi4 ,acetic acid1 as a  
product of the destructive distillation 
of  wood1 was first obtained by ,gttling
 in #aggi4 ,the acetic fermentation  has

 been studied from very early times4    
,surmises as to the mode in  which wine 
was converted into vinegar are to be met
 with in the works  of ,basil           
,valentine1 ,becher 7#affi71 ,lemery    
7#afge71 and ,stahl 7#affg74            
,priestley1 for a time1 held the opinion
 that vinegar contained a  vegetable    
acid air1 but he subsequently discovered
 and corrected his  error4 ,the direct  
conversion of spirit of wine 7ethyl     
alcohol7 into  acetic acid was studied  
by ,lavoisier and ,berthollet1 who first
 clearly  recognised that it was a      
process of oxidation4 ,the quantitative 
composition of acetic acid was first    
established by ,berzelius in #ahad4     
,many of the acetates have been known   
from early times4 ,verdigris is         
mentioned by ,theophrastus1             
,dioscorides1 and ,pliny4 ,zinc acetate 
was  known to ,geber1 and potassium     
acetate to ,pliny1 who mentions its use 
in medicine4 ,ammonium acetate was also 
used in medicine as far back  as the    

beginning of the seventeenth century1   
and was particularly  recommended by the
 physician1 ,raymond ,minderer4 ,sodium 
acetate was  prepared by ,duhamel in    
#agcf4 ,lead acetate was known in the   
fifteenth  century1 and was styled by   
,libavius saccharum plumbi              
quintessentiale1  in allusion to its    
sweet taste4 ,what was called by the    
alchemists lac  virginis was a turbid   
solution of basic lead acetate1 and it  
was  frequently used in medicine1 more  
particularly by ,goulard in #agfj4      
,what we now call acetone was first     
observed by ,libavius1 in #aeie1  and   
subsequently by ,boyle1 during the      
destructive distillation of lead        
acetate3 its formation from other       
acetates was noticed by ,trommsdorff1   
,derosne1 and ,chenevix1 by whom it was 
termed pyroacetic spirit4 ,its  true    
nature and composition were first       
ascertained by ,liebig in #ahca4    ,the
 formation of tartar in the manufacture 
of wine has been known  from the        

earliest times4 ,it was regarded as1 and
 originally styled1  the faex vini4 ,the
 word 8,tartarus0 is first met with in  
alchemistic  literature in the eleventh 
century1 and is the ,latinised form of  
an  ,arabic word4 ,marggraf1 in #agfd1  
recognised that the tartar of wine      
contained potash2 but tartaric acid     
itself was first isolated by  ,scheele  
in #agfi4    ,the double tartrate of    
potash and soda was first prepared in   
#afgb  by ,peter ,seignette1 an         
apothecary of ,rochelle1 and was used by
 him  in medicine4 ,tartar emetic was   
discovered by ,adrian von ,mynsicht  in 
#afca1 and its true nature explained by 
,bergmann in #aggc4 ,racemic  acid was  
first mentioned by a wine manufacturer  
named ,kestner1 and  was recognised as  
an acid in #ahai4 ,its relation to      
tartaric acid1 with  which it is        
isomeric1 was first explained by        
,berzelius1 who gave it its  name4      
,the naturally occurring oxalates were  
long considered as identical with       

tartar4 ,oxalic acid was obtained by    
,scheele in #aggf by means of the       
action of nitric acid upon sugar4 ,this 
acid was further investigated  by       
,bergmann1 who observed its             
decomposition by heat with the formation
  of a gas burning with a blue flame4   
,the identity of the naturally          
occurring oxalic acid with that prepared
 from sugar was established  by ,scheele
 in #aghd4 ,the quantitative composition
 of oxalic acid was  first ascertained  
by ,dulong in #ahae4 ,mucic acid was    
discovered by  ,scheele in #aghj1 and   
was studied by ,fourcroy1 who gave it   
the name it  now bears4 ,pyromucic acid 
was also known to ,scheele1 and was     
observed  by ,hermbstdt and             
,houton-,labillardire4 ,camphoric acid  
was first  recognised by                
,bouillon-,lagrange and ,vauquelin4     
,suberic acid was  discovered by        
,brugnatelli in #aghg4    ,that gum     
benzoin yielded a product 7benzoic acid7
 by sublimation was  known in the       

sixteenth century4 ,it was introduced   
into medicine by  ,turquet de ,mayerne  
as flowers of benzoin4 ,scheele showed  
how this  acid might be obtained by wet 
methods from gum-benzoin4 ,it was       
detected  in ,peru-balsam by ,lehmann in
 #agji4 ,rouelle found it in the urine  
of the  cow and the camel4 ,liebig1 in  
#ahbi1 detected the difference between  
hippuric acid and benzoic acid4 ,the    
characteristic acid in amber  7succinic 
acid7 was first detected by ,pott in    
#agec4    ,formic acid was first        
isolated by ,wray in #afgf4 ,lactic acid
 was  discovered by ,scheele in sour    
milk in #aghj4 ,for a time it was       
regarded  as impure acetic acid1 until  
it was detected in muscle juice by      
,berzelius1 and its individuality       
established4 ,its true composition was  
ascertained by ,mitscherlich and by     
,liebig in #ahcb4 ,citric acid has  been
 known since the thirteenth century1 but
 it was first definitely  isolated by   
,scheele in #aghd4 ,apple juice was used

 in medicine in the  sixteenth century1 
and the soda salt of its characteristic 
acid 7malic  acid7 was prepared by      
,donald ,monro in #agfg4    ,it was     
known to the ancients that extract of   
gall nuts acquired a  black colour when 
mixed with a solution of iron vitriol2  
and ,boyle  and ,bergmann ascribed this 
phenomenon to the presence of a peculiar
  acid4 ,gallic acid was first isolated 
by ,scheele in #aghe1 and its           
composition established by ,berzelius in
 #ahad4 ,tannic acid was  definitely    
recognised as distinct from gallic acid 
by ,seguin in #agie4    ,mellite1 or    
honey-stone1 is mentioned in            
mineralogical treatises in the          
sixteenth century4 ,that it consisted of
 the alumina salt of a special  acid    
7mellic acid7 was shown by ,klaproth in 
#agii4    ,prussian blue was            
accidentally discovered in #agaj by a   
dyer named  ,diesbach4 ,its mode of     
manufacture was first made known by     
,woodward  in #agbd4 ,the peculiar      

reaction by which it was obtained was   
made the  subject of investigation by   
many chemists of the period without any 
decisive result4 ,scheele observed that1
 when the salt which occasioned  the    
blue colour with vitriol was distilled  
with sulphuric acid1 a  volatile acid1  
inflammable and soluble in water1 was   
obtained4 ,this  acid received from     
,bergmann the name of acidum crulei     
berolinensis1  or 8,berlin-blue acid10  
subsequently shortened by ,guyton de    
,morveau  to prussic acid4 ,scheele also
 prepared the cyanides of silver and    
ammonium4 ,that prussic acid was free   
from oxygen was established  by         
,berthollet4 ,anhydrous prussic acid was
 first obtained by ,von  ,ittner1 who   
first established its highly poisonous  
nature4 ,bolim1 in  #ahjb1 had          
previously observed the presence of     
prussic acid in oil  of bitter almonds1 
the poisonous character of which was    
known to  ,dioscorides4 ,porret first   
definitely isolated potassium           

ferrocyanide1  and subsequently         
discovered the thiocyanates1 the        
quantitative  composition of which was  
ascertained by ,berzelius in #ahbj4     
,that  prussic acid was a compound of   
hydrogen and cyanogen was established by
  ,gay ,lussac in #ahae4    ,cyanic acid
 was discovered by ,whler in #ahbb1 in  
which year also ,l4  ,gmelin discovered 
the ferricyanides4    ,fulminating      
mercury was first prepared by ,howard in
 #ahjj1 and  fulminating silver by      
,brugnatelli in #ahjb4 ,these were      
recognised  by ,liebig1 in #ahbb1 to    
contain a peculiar acid1 which he termed
  fulminic acid1 and which he showed to 
have the same composition  as the cyanic
 acid discovered by ,whler4 ,uric acid1 
so named by  ,fourcroy1 was discovered  
in gall stones by ,scheele in #aggf4    
,urea was  first definitely isolated by 
,fourcroy and ,vauquelin in #agii1 and  
was  synthetically prepared by ,whler in
 #ahbh4    ,the bitter principles of    
plants and their medicinal virtues early

  attracted attention1 but the first    
attempt to isolate them was made by     
,fourcroy and ,vauquelin in the case of 
the ,peruvian bark1 long known for  its 
power as a febrifuge4 ,in #ahjf         
,vauquelin obtained quinic acid4        
,cinchonine was first isolated by ,gomes
 in #ahaa4    ,the chemical nature of   
opium was the subject of numerous       
inquiries in  the early years of the    
nineteenth century4 ,in #ahje ,sertrner 
detected  the existence of meconic acid1
 and in #ahag that of morphine1 which   
he recognised as an alkaloid4 ,narcotine
 was discovered by ,robiquet in  #ahce4 
,the investigation of other bitter      
substances was undertaken by  ,pelletier
 and ,caventou1 who in #ahah discovered 
strychnine1 brucine  7#ahai71 and       
veratrine 7#ahbj74    ,the              
contemporaries and immediate followers  
of ,lavoisier were the  first to make a 
systematic attempt to elucidate the     
chemical nature  of organic products of 
animal origin4 ,to this period belongs  

the work  of ,fourcroy and ,vauquelin on
 animal chemistry4 ,chevreul1 a pupil of
  ,fourcroy worked on urine1 adipocire1 
and the animal fats in the first  decade
 of the last century4 ,kirchhoff in     
#ahaa1 discovered the method  of        
converting starch into sugar2 and       
,dbereiner1 in #ahbb1 described  a      
method of preparing formic acid         
artificially4 ,dumas and ,boullay1  in  
#ahbg-ahbh1 prepared a number of new    
derivatives of ethyl alcohol2  and in   
#ahcd ,dumas and ,peligot studied in    
like manner the chemistry of  methyl    
alcohol1 and pointed out many analogies 
which their compounds  possessed1 not   
only among themselves1 but also to      
inorganic substances4    ,although a    
considerable amount of information as to
 the existence1  modes of occurrence1   
and properties of bodies found in the   
animal  and vegetable kingdoms had been 
accumulated by the end of the first     
quarter of the nineteenth century1 no   
serious attempt was made to  study them 

systematically until after that period4 
,in fact1 they  were not even regarded  
as coming within the operations of laws 
found to be applicable to the products  
of the inorganic world1 by  the         
investigation1 of which products1       
indeed1 those laws had been  discovered4
    ,down to #ahbh it was considered    
that inorganic and organic substances   
were sharply differentiated by the      
circumstance that1 whereas the  former  
might be prepared by artificial means1  
and even built up from  their elements  
by synthetic processes in the           
laboratory1 the latter  could only be   
formed in the bodies of animals and     
plants as the result  of vital force4   
,in that year ,whler showed that urea1  
pre-eminently  a product of animal      
metabolism1 could be prepared           
synthetically from  inorganic materials4
 ,other instances of a similar kind were
 discovered  in rapid succession2 and   
the idea that organic substances could  
alone  be formed by vital processes was 

proved to be invalid4 ,moreover1 large  
numbers of substances of a character    
analogous to those produced by          
physiological action1 but not known to  
occur in the animal or vegetable        
kingdom1 were prepared4 ,there is1      
therefore1 no absolute distinction to   
be drawn between the chemistry of the   
inorganic and organic worlds4    ,at the
 present day we mean by 8organic        
compounds0 simply the compounds  of     
carbon4 ,these are so numerous1 and     
frequently so complex1 that  it is      
convenient to group them together and   
study them as a special  section of the 
science4 ,at the outset it was supposed 
that only very  few elements entered    
into the composition of organic         
substances4 ,this1  indeed1 was held to 
be a point of fundamental distinction   
between  organic and inorganic          
compounds4 ,lavoisier was of opinion    
that all  organic bodies were           
combinations of carbon1 hydrogen1 and   
oxygen4  ,berthollet first discovered   

the presence of nitrogen in a product   
of animal origin4 ,sulphur and          
phosphorus were detected later4 ,there  
is apparently no  priori reason why any 
element should not be  associated with  
carbon1 and enter into the composition  
of an organic  compound4    ,lavoisier  
was one of the first to devise methods  
for ascertaining  the composition of    
organic 7carbon7 compounds1 and to      
indicate the  general principles by     
which the proportion of the elements met
 with  in these substances can be       
ascertained4 ,so imperfectly1 however1  
were  these methods worked out that it  
was not established until the close  of 
the first decade of the nineteenth      
century that organic compounds  even    
obeyed the law of multiple proportions4 
,thanks to the efforts  of ,berzelius1  
,gay ,lussac1 and ,thnard1 and          
especially of ,liebig1 in  #ahcj1       
methods of organic analysis were so far 
perfected that it became  possible to   
ascertain the empirical composition of  

these compounds  with certainty4 ,this  
point reached1 the development of this  
section  of chemistry proceeded with    
unexampled rapidity4 ,not only was the  
composition of numbers of products1 such
 as sugar1 starch1 the  vegetable acids1
 certain alkaloids1 etc41 established1  
but altogether  unlooked-for facts      
became manifest4 ,one of the most       
surprising of these  was that of        
isomerism4    ,up to the close of the   
first quarter of the nineteenth century 
it  seemed self-evident that substances 
of the same percentage composition  are 
necessarily identical4 ,in #ahbc ,liebig
 showed that the silver  cyanate of     
,whler had the same composition as      
silver fulminate4  ,faraday1 in #ahbe1  
found a hydrocarbon in oil gas1 which   
had the same  composition as olefiant   
gas1 but was otherwise different from   
it2 and  in #ahbh ,whler discovered that
 urea and ammonium cyanate--perfectly   
dissimilar substances--were identical in
 elementary composition4 ,lastly1       

,berzelius found this to be true of     
tartaric and racemic acids2 and he      
thereupon proposed the term isomerism to
 denote the general fact4  ,he further  
pointed out that the phenomenon could   
only be explained  by supposing that the
 relative positions of the atoms in     
isomeric  compounds are different4      
,but the influence of molecular or      
atomic grouping in determining  the     
specific character of a substance is not
 confined to compounds4  ,the same      
phenomenon is observed to occur among   
the elements4 ,it was  conclusively     
established by ,lavoisier that the      
diamond and charcoal  are chemically the
 same thing--both forms of carbon4      
,scheele showed that  graphite was a    
third form of carbon4 ,phosphorus1      
sulphur1 and oxygen  were subsequently  
shown to be each capable of existence in
 various  modifications4 ,instances of  
this character were grouped together in 
#ahda by ,berzelius under the term      
allotropy4    ,the recognition of the   

fact of isomerism exerted a great       
influence  on the development of organic
 chemistry4 ,it ultimately led to the   
assumption that particular groups of    
elements or atomic complexes1  so-called
 radicals1 were to be found in organic  
compounds--a  conception based          
originally on ,gay ,lussac's discovery  
of cyanogen1  a combination of carbon   
and nitrogen1 which was found to behave 
like  a simple substance1 such as       
chlorine1 and to give rise to compounds 
analogous to the corresponding          
chlorides4 ,this idea of the existence  
of  compound radicals was greatly       
strengthened by a memorable             
investigation  by ,liebig and ,whler1 in
 #ahcb1 on oil of bitter almonds and its
  derivatives1 in which they showed that
 these substances might be  represented 
as containing a special group or radical
 termed benzoyl1  which behaved like an 
element4 ,the idea of groups of elements
 going  in and out of combination like a
 simple substance was not new to        

chemists3 there was not only the case of
 cyanogen1 discovered by ,gay  ,lussac  
in #ahae4 ,the attempt had been made by 
,dumas and ,boullay in  #ahbh to        
classify the derivatives of alcohol and 
ether as compounds  containing a common 
radical etherin4 ,gay ,lussac had       
pointed out that  the vapour density of 
ethyl alcohol seemed to show that it    
consisted  of equal volumes of ethylene 
and water4 ,robiquet had also shown that
  ethyl chloride might be assumed to be 
a compound of hydrochloric acid  and    
ethylene2 and ,dbereiner had regarded   
anhydrous oxalic acid as a  combination 
of carbonic acid with carbonic oxide4   
,but the investigation of ,liebig and   
,whler served to give precision  to the 
conception4 ,it thereby exercised a     
profound influence on the  development  
of organic chemistry by demonstrating1  
in effect1 that  this branch of the     
science might be regarded as the        
chemistry of the  compound radicals1 in 
contradistinction to inorganic          

chemistry--the  chemistry of the simple 
radicals4 ,additional support for this  
view  was afforded by the remarkable    
research by ,bunsen on the so-called    
alkarsin1 the 8fuming liquor of         
,cadet0--an evil-smelling substance     
long known as being formed when an      
acetate is heated with arsenious  oxide4
 ,bunsen showed that this liquid        
contained a compound radical  having    
arsenic as a constituent2 and he        
prepared a series of  derivatives1 all  
of which might be formulated as         
combinations of this  radical1 which he 
termed cacodyl4 ,the study of the       
electrolytic  decomposition of the      
acetates by ,kolbe and the discovery of 
zinc-ethyl by ,frankland afforded       
powerful support to the doctrine of     
combined radicals4    ,although there   
can be no doubt that this doctrine      
greatly stimulated  the pursuit of      
organic chemistry1 it was gradually     
perceived that to  regard inorganic and 
organic chemistry as the chemistry      

respectively of  the simple and of the  
compound radicals was an imperfect and  
misleading  conception of the true      
relations of the two main divisions of  
the  science4 ,facts showed that the    
properties of a substance depend more   
on the arrangement of its atoms than on 
their nature4 ,the doctrine of  compound
 radicals was implicitly an attempt to  
extend the dualistic  conceptions of    
,berzelius to the facts of organic      
chemistry2 and as such  it was welcomed 
by the great ,swedish chemist4 ,but     
dualism was found to  have its          
limitations1 even in inorganic          
chemistry2 and these were still  more   
apparent when it was sought to apply it 
in the other main branch  of the        
science4 ,attempts were therefore       
made--notably by the ,french  chemists  
,laurent1 ,dumas1 and ,gerhardt--to     
formulate organic substances  by methods
 in which the electro-chemical and      
dualistic conceptions of  ,berzelius and
 his followers had no part4 ,how these  

attempts developed1  and how they       
subsequently grew into the organic      
chemistry of to-day1  will be shown in  
the second part of this work4    ,it    
will be convenient also to delay any    
account of the personal history  of the 
creators of the science of organic      
chemistry--,liebig1 ,whler1             
,dumas--until we are in a position to   
give a fuller statement of their        
labours1 and of the results which flowed
 from them4 ,although the  foundations  
of organic chemistry may be said to have
 been laid during  the closing years of 
the first half of the nineteenth        
century1 the  superstructure was not    
erected until the second half4          
,,chapter ,,xii    ,,the ,,rise ,,of    
,,physical ,,chemistry      ,physics and
 ,chemistry are twin sisters--daughters 
of ,natural ,philosophy2  like ,juno's  
swans1 coupled and inseparable4 ,physics
 is concerned  with the forms of energy 
which affect matter2 chemistry with the 
study of matter so affected4 ,each1     

then1 is complementary to the  other4   
,philosophers of old drew no practical  
distinction between  them1 at least as  
regards their own studies4 ,men like    
,boyle1 ,black1  ,cavendish1 ,lavoisier1
 ,dalton1 ,faraday1 ,graham1 ,bunsen1   
were pioneers  8on a very broad gauge10 
pushing their inquiries into territories
  common to the two branches as their   
genius or inclinations directed  them4  
,accordingly1 it has happened that many 
so-called physical laws  have been      
discovered by men who were professed    
chemists4 ,it has also  happened that   
men who began their scientific career as
 chemists1 like  ,dalton1 ,regnault1 and
 ,magnus1 eventually gave the whole of  
their  energies to physical             
measurements2 or1 like ,black1 ,faraday1
 and  ,graham1 devoted themselves to the
 elucidation of physical problems4 ,as  
certain of these physical laws and      
problems have greatly influenced  the   
progress of chemistry1 it becomes       
necessary1 in any historical  treatment 

of the subject1 to give some account of 
their origin1 and to  show how they     
affected the development of chemical    
theory4    ,the relations of heat to    
chemical phenomena are so obvious and so
  intimate that the study of their      
connection necessarily attracted        
attention in very early times4 ,but it  
was only when this study became         
quantitative that any important         
generalisations became possible4  ,most 
quantitative estimations of heat depend 
eventually upon the  thermometer2 and   
thermometry is indebted to ,englishmen  
in the first  instance for attempts to  
render the instrument trustworthy4      
,in this connection may be mentioned the
 names of ,newton and ,shuckburgh4      
,brooke ,taylor1 in #agbc1 made a       
special study of the mercurial          
thermometer as a measurer of            
temperature4 ,in other words1 he sought 
to discover whether equal differences of
 expansion or contraction of  mercury   
corresponded to equal additions or      

abstractions of heat4 ,the  results     
showed that the principle of the        
mercurial thermometer is valid  within  
at least the limits of temperature      
between the boiling and  freezing-points
 of water4 ,these experiments were      
subsequently repeated  and confirmed by 
,cavendish1 and1 independently1 by      
,black4    ,the discovery of the        
phenomenon of latent heat by ,black some
 time  prior to #agfj marks an epoch in 
the history of science4 ,it was then for
  the first time clearly recognised that
 the state of aggregation of a          
substance is associated with a definite 
thermal quantity1 and that1 in  order to
 effect a change1 a definite amount of  
energy1 in the form of  heat1 must be   
employed4 ,the quantitative connection  
that exists between  work and energy was
 thus foreshadowed4    ,the doctrine of 
specific heat was taught by ,black in   
his lectures  at ,glasgow between #agfa 
and #agfe4 ,the subject was subsequently
  investigated experimentally by ,irvine

 between #agfe and #aggj1 and by        
,crawford in #aggi4 ,a series of        
determinations was published in #agha by
  ,wilcke1 in the ,transactions of the  
,swedish ,academy4 ,in these the  term  
specific caloric1 since changed to      
specific heat1 was first  used4 ,about  
this time the determination of the      
amount of heat required  to raise       
substances through a definite interval  
of temperature was  made the subject of 
experiment by many observers1 notably by
 ,lavoisier  and ,laplace1 who greatly  
improved the calorimetric arrangements4 
,the  values they obtained long remained
 the most trustworthy estimations of    
the specific heats of substances4 ,their
 joint research had a further  influence
 on the development of thermo-chemistry 
by indicating the  general experimental 
conditions which were needed to ensure  
accuracy  in such determinations4       
,lavoisier and ,laplace also measured1  
in  #aghb-aghc1 the heat disengaged by  
the combustion of substances1 and  that 

evolved during respiration4 ,in #ahai   
,dulong and ,petit pointed out  that the
 specific heat of a number of           
substances1 more particularly the       
metals1 were inversely proportional to  
their atomic weights2 or1 in  other     
words1 the product of the specific heat 
into the atomic weight  was a constant4 
,the nature of the relation will be seen
 from the  following table of certain of
 the results obtained by ,dulong and    
,petit3--        ,element4  ,at4 wt4    
,spec4 heat4  ,atomic heat4             
,bismuth     #bjh      #j4jbhh          
#f4j      ,lead        #bjg      #j4jbic
         #f4j      ,gold        #aig    
#j4jbih         #e4h      ,platinum     
#aie      #j4jcad         #f4a          
,silver      #ajh      #j4jegj          
#f4a      ,copper       #fc      #j4jieb
         #f4j      ,iron         #ef    
#j4aach         #f4d    ,it will be seen
 that these various elements have an    
uniform1 or nearly  uniform1 atomic     
heat--approximately #f4b on the average4

    ,this would appear to prove that1 as
 ,dulong and ,petit expressed  it1 8the 
atoms of simple substances have equal   
capacities for  heat40 ,the variations  
from a constant value are due partly to 
errors of observation1 but more         
particularly to the circumstance  that  
the substances compared are not all in a
 strictly comparable  condition--e4g41  
they are not all equally remote from    
their melting  points4 ,it was shown1   
moreover1 that the amount of heat needed
 to raise  a substance through a        
definite interval of temperature        
increased with  the temperature4 ,the   
range of temperature through which a    
determination  was made in a particular 
instance affected1 therefore1 the value 
of  the specific heat4 ,the most        
noteworthy departures from a uniform    
value  were observed to occur among the 
metalloids--e4g41 carbon1 the various   
modifications of which had different    
specific heats--and generally among     
elements of low atomic weight1 in which 

the variation of specific heat  with    
temperature was particularly rapid4     
,nevertheless1 the significance of the  
generalisation discovered by  ,dulong   
and ,petit1 in spite of its limitations1
 was quickly appreciated1  as it was    
perceived that a knowledge of the       
specific heat of an element  might be of
 great value in determining its atomic  
weight4 ,the immediate  effect was that 
a certain number of the atomic weights  
fixed by  ,berzelius mainly on chemical 
considerations were required to be      
halved4  ,although subsequent experience
 has proved that the law of ,dulong and 
,petit is not capable of the simple     
mathematical expression they gave  it1  
it has shown itself to be of great value
 in fixing doubtful atomic  weights4    
,pierre ,louis ,dulong was born in #aghe
 at ,rouen1 and1 after studying         
chemistry and physics at the            
,polytechnic ,school at ,paris1 became  
its  ,professor of ,chemistry and       
subsequently its ,professor of ,physics4

  ,in #ahcj he was made its ,director of
 ,studies2 and in #ahcb he became       
permanent ,secretary of the ,academy of 
,sciences4 ,as a young man he  worked   
with ,berzelius1 with whom he made the  
first approximately  accurate           
determination of the gravimetric        
composition of water4 ,in  #ahaa he     
discovered the highly explosive nitrogen
 chloride1 in the  investigation of     
which he was severely injured1 losing an
 eye and  several fingers4 ,he died in  
#ahch4 ,his collaborator1 ,alexis       
,therese  ,petit1 was born in #agia at  
,vesoul1 and died1 when holding the     
position  of ,professor of ,physics at  
the ,lyce ,bonaparte1 in #ahbj4    ,the 
attempt made by ,neumann to extend      
,dulong and ,petit's 8law0 to  compound 
substances was only partially           
successful4 ,nor has any  important     
generalisation followed from our        
knowledge of the specific  heat of      
liquids4 ,almost simultaneously with the
 publication of ,dulong  and ,petit's   

8law10 ,mitscherlich made known the fact
 that similarity  in chemical           
constitution is frequently accompanied  
by identity of  crystalline form4       
,boyle1 as far back as the middle of the
 seventeenth  century1 had insisted upon
 the importance of the forms of crystals
  in throwing light upon the internal   
structure of bodies4 ,rom de  l',isle   
and ,hauy had remarked that many        
different substances had the  same      
crystalline form4 ,it had been observed 
that a crystal of potash  alum would    
continue to grow and preserve its shape 
in a solution of  ammonia alum2 and     
similar observations had been shown to  
occur in  the case of vitriols4 ,the    
invention of the reflecting goniometer  
by  ,wollaston greatly facilitated the  
investigation of such phenomena4        
,mitscherlich showed that the phosphates
 and arseniates of analogous            
composition had the same crystalline    
shape1 or1 in other words1 were         
isomorphous4 ,the same fact was observed

 to occur in the case of the            
analogously constituted sulphates and   
selenates1 and in that of the  oxides of
 magnesium and zinc1 etc4 ,the value of 
isomorphous relations  in determining   
the group-relationships of the elements 
and in deducing  the composition of     
salts was at once recognised by         
,berzelius1 who  styled the discovery of
 isomorphism by his pupil ,mitscherlich 
as 8the  most important since the       
establishment of the doctrine of        
chemical  proportions40 ,the quantities 
of the isomorphously replacing elements 
in  a compound were regarded by him as a
 measure of their atomic weights2  and  
the principle was subsequently          
constantly employed by him1 whenever    
possible1 as a criterion in fixing their
 values4 ,other investigators  have     
followed his example in this respect2   
and isomorphism is still  regarded as an
 important consideration in establishing
 the genetic  relations of an element4  
,eilhard ,mitscherlich1 the son of a    

minister1 was born in #agid at  ,neu    
,ende1 near ,jever1 in ,oldenburg1 and1 
after studying philology  and oriental  
languages at ,heidelberg1 went to       
,paris1 and thence to  ,gttingen1 where 
he occupied himself with natural        
science4 ,in #ahah  he repaired to      
,berlin and commenced to work on the    
arseniates and  phosphates1 the         
similarity in the crystal-forms of which
 he was the  first to detect4 ,his      
friend ,gustav ,rose1 the mineralogist1 
thereupon  instructed him in the methods
 of crystallography2 to enable him to   
verify his discovery and to establish it
 by goniometric measurements4  ,in #ahba
 he joined ,berzelius at ,stockholm1    
where he pursued his  inquiries on the  
connection between crystal-form and     
chemical  composition4 ,it was at the   
suggestion of ,berzelius that he adopted
 the  term 8isomorphy0 to express this  
connection--the mechanical consequence  
of identity of atomic constitution4 ,in 
the same year he was appointed          

,klaproth's successor in ,berlin1 where 
he died in #ahfc4    ,mitscherlich also 
worked on the manganates and            
permanganates1 on  selenic acid1 on     
benzene and its derivatives1 and on the 
artificial  production of minerals4     
,the study of the physical phenomena of 
gases1 initiated in #affj  by ,boyle's  
discovery of the law of gaseous         
pressure1 has greatly  contributed to   
our knowledge of their intrinsic nature4
 ,boyle himself  only proved his law in 
the case of atmospheric air2 but the    
observation  was subsequently 7#afgf7   
generalised by ,marriotte4 ,charles1    
,dalton1  and ,gay ,lussac independently
 showed that gases have the same rate of
  thermal expansion4    ,that gases are 
made up of particles possessing an      
internal movement was  surmised by the  
,greeks2 but experimental evidence for  
such a view of  their constitution was  
first presented by ,thomas ,graham in   
#ahbi-ahca1  when he discovered that    
gases move1 or are diffused1 at rates   

inversely  proportional to the square   
roots of their densities4 ,observations 
of a  like character1 which found their 
explanation in ,graham's discovery1  had
 previously been made by ,priestley1    
,dbereiner1 and ,saussure4 ,this        
interchange in the position of their    
particles is a property inherent  in    
gases4 ,inequality of density is not    
essential to diffusion4 ,graham  proved 
this by connecting together two vessels1
 one containing nitrogen  and the other 
carbonic oxide1 which have the same     
density4 ,after the  expiration of a    
certain time both gases were found to be
 uniformly  diffused through the        
vessels4    ,how these laws were found  
to be interdependent and mutually       
connected1  and how they led up to a    
molecular theory of gases which serves  
to explain them1 as well as certain     
other gaseous phenomena to be           
subsequently noted1 will be shown in the
 second part of this work4    ,by the   
end of the period with which we are     

concerned--that is1 the  middle of the  
nineteenth century--a considerable body 
of information had  been accumulated as 
to the conditions which determine the   
different  states of aggregation of     
matter--that is1 the conditions which   
allow of  the passage of the gaseous    
state into that of the liquid1 and of   
the  liquid into that of the solid4     
,that the same substance was capable of 
existence in the three states of gas1   
liquid1 and solid was of course  evident
 from the case of water4 ,even the most 
primitive races must  have realised that
 steam1 dew1 rain1 snow1 hail1 and ice  
were only  modifications of one and the 
same substance4 ,as knowledge increased1
  other substances came to be known     
which resembled water in their  capacity
 for existence in various physical      
states4 ,it was but natural  to assume  
that this was a general attribute1 and  
that all substances  would1 sooner or   
later1 be found capable of existence in 
each of the  different conditions of    

aggregation4    ,attempts were made     
during the first quarter of the last    
century to  prove that all the riform   
bodies then known were simply vapours   
more or less remote from their point of 
liquefaction1 and still  further removed
 from their point of congelation4 ,monge
 and ,clouet  condensed sulphur dioxide 
some time before #ahjj2 and ,northmore1 
in #ahje1 liquefied chlorine4 ,but these
 observations attracted  little         
attention until ,faraday1 in #ahbc1     
independently effected the  liquefaction
 of chlorine1 and ,davy that of         
hydrochloric acid4 ,faraday  almost     
immediately afterwards liquefied sulphur
 dioxide1 sulphuretted  hydrogen1 carbon
 dioxide1 euchlorine1 nitrous oxide1    
cyanogen1 and  ammonia4    ,other       
experimenters1 among whom may be        
mentioned ,thilorier and  ,natterer1    
greatly improved the mechanical         
appliances for liquefying  these gases2 
liquid carbonic acid and nitrous oxide  
were obtained  in considerable          

quantities1 and employed in the         
production of cold4  ,certain of the    
gases--hydrogen1 oxygen1 nitrogen1      
nitric oxide1 carbonic  oxide1          
etc4--resisted all attempts to liquefy  
them2 and hence gaseous  substances came
 to be classified as permanent and      
non-permanent1  depending upon whether  
they could or could not be liquefied4   
,the  division was felt to be irrational
 even at the time it was made4 ,there   
seemed no  priori reason why carbon     
dioxide and nitrous oxide should  be    
liquefiable1 while carbonic oxide and   
nitric oxide should resist  all attempts
 to coerce them into changing their     
state4 ,the real clue  to the conditions
 required to effect the liquefaction of 
a gas was  not discovered until nearly  
half a century later1 when1 as will be  
shown subsequently1 the arbitrary       
division of gases into permanent and    
non-permanent was swept away4    ,the   
discovery of the law of gaseous         
combination by ,gay ,lussac1 and the    

recognition by ,ampre and ,avogadro of  
the relation between the density  of a  
gas or a vapour and its atomic weight1  
early led to improvements  in the       
methods of determining the absolute     
weights of gases and  vapours1          
especially by ,french chemists4 ,both   
,gay ,lussac and ,dumas  devised        
processes for determining vapour        
densities which were in use  until late 
in the century1 and which1 although now 
superseded by more  convenient and more 
rapid modifications afforded valuable   
information  concerning the molecular   
weights of substances and the phenomena 
of  gaseous dissociation4    ,during the
 first decade of the nineteenth century 
,dalton and ,henry  discovered the      
simple law which connects pressure with 
the solubility  of a gas in any solvent 
upon which it exerts no specific action4
 ,dalton  further developed the law so  
as to include the absorption by a       
solvent  of the several constituents of 
a gaseous mixture4    ,attempts were    

made by ,schrder1 ,kopp1 and others1 to 
discover  relations between the weights 
of unit volumes of liquids and solids   
and their chemical nature2 but such     
attempts were only partially            
successful1 owing to the difficulty of  
finding valid conditions  of comparison4
 ,by comparing the specific gravities of
 liquids  at their boiling-points ,kopp 
succeeded in detecting a number of      
regularities among their specific       
volumes which seem to indicate that  a  
comprehensive generalisation connecting 
them may yet be discovered4  ,kopp has  
also shown that regularities exist among
 the boiling-points  of correlated      
substances1 and that there is an        
interdependence between  the temperature
 of their ebullition and the chemical   
characters of  compounds4    ,this short
 summary will suffice to show that      
attempts to discover  relations between 
the physical attributes of substances   
and their  chemical nature were made    
more or less sporadically from the time 

that chemistry was pursued in the spirit
 of science4 ,but it is only  in recent 
times that any great accession to       
knowledge has resulted  from such       
efforts4 ,the science of physical       
chemistry is practically a  creation of 
our own period4 ,its systematic study   
may be said to date  only from the last 
quarter of the nineteenth century1 since
 which time  it has made extraordinary  
progress4 ,its broad features will be   
dealt  with in the second volume of this
 work4          ,,bibliography          
,,relating ,,to ,,the ,,period ,,covered
 ,,by ,,vol4 ,i4      ,agricola1 ,georg4
 ,de ,re ,metallica4    ,agricola1      
,georg4 ,vom ,bergwerck ,,xii4 ,bcher   
darinn mit schner  ,figuren1 etc4       
,alembic ,club1 ,publications of the4   
,w4 ,clay1 ,edinburgh4    ,beddoes1     
,thomas4 ,chemical ,essays of ,scheele4 
,murray1 ,london1 #aghf4    ,berthelot1 
,marcellin4 ,la ,chimie des ,anciens et 
du ,moyenge4  ,steinheil1 ,paris1 #ahhi4
    ,berthelot1 ,marcellin4 ,la         

,rvolution ,chimique4 ,flix ,alcan1     
,paris1  #ahij4    ,berthollet1 ,c4 ,l4 
,essai de ,statique ,chimique4 ,firmin  
,didot1 ,paris1  #ahjc4    ,birch1      
,thomas4 ,life of ,boyle4 ,millar1      
,london1 #agdd4    ,boerhaave1 ,hermann4
 ,new ,method of ,chemistry4 ,shaw and  
,chambers1  ,london1 #agbg4    ,boulton1
 ,richard4 ,boyle's ,works ,epitomised4 
,phillips and ,taylor1  ,london1 #afii4 
,burton1 ,w4 ,life of ,boerhaave4       
,lintot1 ,london1 #agdf4    ,dalton1    
,john4 ,a ,new ,system of ,chemical     
,philosophy4 ,two ,vols4  ,bickerstaff1 
,london1 #ahjg-ahaj4    ,davy1 ,john4   
,life of ,sir ,humphry ,davy4 ,longmans1
 ,london1 #ahcf4    ,davy1 ,humphry4    
,collected ,works4 ,edited by ,john     
,davy4 ,smith1 ,elder1  and ,co41       
,london1 #ahci4    ,figuier1 ,louis4    
,l',alchimie et les ,alchimistes4       
,victor ,lecon1 ,paris1  #ahee4    ,gay 
,lussac and ,thnard4 ,recherches        
,physico-,chimiques4 ,deterville1       
,paris1 #ahaa4    ,gerding1 ,th4        

,geschichte der ,chemie4 ,zweite        
,ausgabe4 ,grunow1 ,leipzig1  #ahfi4    
,grimaux1 ,edouard4 ,lavoisier1         
#agdc-agid4 ,flix ,alcan1 ,paris1 #ahhh4
    ,henry1 ,william ,charles4 ,life of 
,dalton4 ,cavendish ,society1 ,london1  
#ahed4    ,hoefer1 ,ferdinand4 ,histoire
 de la ,chimie4 ,two vols41 ,deuxime    
dition4 ,firmin ,didot ,frres1 ,paris1  
#ahff4    ,jones1 ,bence4 ,life and     
,letters of ,faraday4 ,longmans1        
,london1 #ahgj4    ,kopp1 ,hermann4     
,geschichte der ,chemie4 ,four vols4    
,braunschweig1  #ahdc-dg4    ,kopp1     
,hermann4 ,die ,alchemie in lterer und  
neuerer ,zeit4 ,heidelberg1  #ahhf4     
,ladenberg1 ,albert4 ,history of        
,chemistry ,since the ,time of          
,lavoisier4  ,translated by ,leonard    
,dobbin4 ,alembic ,club1 ,edinburgh1    
#aijj4    ,lavoisier4 ,complete ,works4 
,edited by ,dumas4 ,four vols4 ,paris1  
#ahfd4    ,lemery1 ,nicolas4 ,cours de  
,chimie4 ,paris1 #afge4    ,meyer1      
,ernst v4 ,history of ,chemistry4       

,translated by ,george ,m',gowan4       
,macmillian and ,co41 ,london1 #ahia4   
,nordenskild1 ,a4 ,e4 ,carl ,wilhelm    
,scheele4 ,norsledt and ,sner1          
,stockholm4    ,ostwald's ,klassiker der
 ,exakten ,wissenschaften4    ,paris1   
,john ,ayrton4 ,life of ,sir ,humphry   
,davy4 ,colbourne and ,bentley1         
,london1 #ahca4    ,priestley1 ,joseph4 
,experiments and ,observations on       
,different ,kinds of  ,air4 ,six vols4  
,j4 ,johnson1 ,london1 #agge et seq4    
,roscoe1 ,h4 ,e41 and ,harden1 ,a4 ,a   
,new ,view of the ,origin of ,dalton's  
,atomic ,theory4 ,macmillian and ,co41  
,london4    ,schmieder4 ,geschichte der 
,alchimie4 ,halle1 #ahcb4    ,schubert1 
,e41 und ,sudhoff1 ,k4 ,paracelsus's    
,forschungen4 ,frankfurt1  #ahhg-hi4    
,shaw1 ,peter4 ,stahl's ,chemistry4     
,osborn and ,longman1 ,london4          
,stahl1 ,g4 ,e4 ,cheimia ,rationalis    
7#agbj74    ,stahl1 ,g4 ,e4 ,zymotechnia
 ,fundamentalis1 etc4 7#afig74          
,stange1 ,albert4 ,zeitalter der        

,chemie4 ,otto ,wigand1 ,leipzig1 #aijh4
    ,thomson1 ,thomas4 ,history of      
,chemistry4 ,two vols4 ,colbourne and   
,bentley1 ,london1 #ahcj4    ,thorpe1   
,t4 ,e4 ,essays in ,historical          
,chemistry4 ,second edition4            
,macmillian and ,co41 ,london1 #aijb4   
,thorpe1 ,t4 ,e4 ,humphry ,davy1 ,poet  
and ,philosopher4 ,cassells1 ,london1   
#ahie4    ,thorpe1 ,t4 ,e4 ,joseph      
,priestley4 ,dent and ,co41 ,london1    
#aijf4    ,wilson1 ,george4 ,life of    
,cavendish4 ,cavendish ,society1        
,london1 #ahea4          ,,index        
neas ,garus1 #ce        ,agricola1      
,georg1 #ff        ,aidoneous1 god of   
earth1 #bb        ,albertus ,magnus1    
#dj1 #dg        ,alchemy1 #bh        and
 astrology1 #cf        its character1   
#ci        ,alkahest1 #ea               
,anastatius the ,sinaite1 #ce           
,anaxagoras1 #bf        ,anaximenes1 #ba
        ,aqua regia1 #ci        ,arabian
 learning1 influence on ,western        
,europe1 #be        ,archus1 #ei        

,argentarium1 #aj        ,argentum      
vivum1 #aa        ,aristotle1 his       
doctrine of 8elements01 #bc        his  
character as a man of science1 #bd      
,arnoldus ,villanovanus 7,arnaud de     
,villeneuve71 #db1 #dg1 #dh1 #ea        
,arvidson1 #aee        ,arrenichon1 #ac 
,ars ,transmutatoria1 #df               
,artephius1 #di        ,astrology and   
alchemy1 #cf        ,atoms1 ancient     
theories of1 #bf        ,atramentum1 #ad
        ,aurichalcum1 #i        ,auri   
pigmentum 7orpiment71 #ac               
,averroes1 #be1 #ch        ,avicenna1   
#ch        ,avogadro1 #aha              
,bacon1 ,roger1 #dj1 #da        ,bacon1 
,lord1 #ee        ,baldwin's phosphorus1
 #hj        ,bartoletti1 ,fabrizio1 #aee
        ,basil ,valentine1 #dc1 #dg1    
#di1 #aef        ,bathurst1 ,ralph1 #gd 
,becher1 ,john ,joachim1 #ha1 #aef      
,benther1 ,david1 alchemist1 #ec        
,bergman1 #id1 #ajg1 #abd1 #aeh1 #afj   
,berigard de ,pisa1 #dh                 
,berthollet1 ,claude-,louis1 #aaf et    

seq41 #aef1 #afj1 #afd                  
,berthelot1 #cg        ,berzelius1 ,jns 
,jakob1 #acc1 #aef1 #aei1 #afj1 #afd    
,black1 ,joseph1 #ih et seq41 #aga      
,bochart1 #d        ,boerhaave1 #c-bj1  
#ce1 #db1 #di1 #ea1 #ajf        his life
 and work1 #hd et seq4        ,bolim1   
#afj        ,borri1 #ec                 
,botryitis1 #ab                         
,bouillon-,lagrange1 #aeh               
,boullay1 #afb1 #afg        ,boyle1     
,robert #bj1 #gb et seq41 #ajg1 #aac1   
#aee1 #aeg1 #aei1 #age1 #agg            
,bragadino1 alchemist1 #ec              
,brooke ,taylor1 #aga                   
,brugnatelli1 #aeh1 #afa                
,cadmia1 #ab        ,cruleum1 #ab       
,caligula1 #cd        ,carbunculus1 #dh 
,cardan1 #aaj        ,cavendish1 #id1   
#ajb et seq41 #ajg1 #aga                
,caventou1 #afb        ,cerium1 its     
discovery1 #aba        ,cerussa1 #aj    
usta1 #ab        ,chalcantum 7copper    
sulphate71 #ab        ,charles1 #agh    
,chalybes1 smelters of iron1 #aa        

,chemistry of the ancients1 #a          
,chenevix1 #aeg        ,chevreul1 #ed1  
#afb        ,chlorine1 discovery of1    
#ajg        ,chromium1 discovery of1    
#abj        ,chrysocolla1 #ab           
,cinnabar1 use as pigment1 #ac          
,clouet1 #ahj        ,clytemius1 ,john1 
#ed        ,cobalt1 discovered by       
,brandt1 #ajg        ,combining         
proportion1 #abi        ,conservation of
 matter1 #aac        ,conringius1       
,hermann1 #ea        ,copper1 ,egyptian1
 #h        ,roman1 #i        ,cordus    
,valerius1 #fi        ,crawford1 #ajg1  
#agb        ,croll1 ,oswald1 #fe        
,cronstedt1 #ajg        ,cyanogen1      
discovery of1 #aea          ,dalton1    
#abe et seq41 #agh1 #aha        ,davy1  
#bi1 #ada        ,dee1 ,john1 #ec       
,delambre1 #aaf        ,demokritos1 #bf 
,de ,re ,metallica1 #ff        ,derosne1
 #aeg        ,dickinson1 #ej            
,diodorus ,siculus1 #g                  
,dioscorides1 #aef1 #afj                
,dbereiner1 #aee1 #afb1 #afg            

,dorn1 #fj        ,duchesne1 #fa        
,duhamel1 #ih1 #aeg        ,dumas1 #afb1
 #afg1 #afh1 #aha        ,dulong1 #aeh1 
#agc1 #agd        ,dyeing by the        
,egyptians1 #ad          ,egypt1        
birthplace of chemistry1 #a             
,electrum1 #h        ,elementa ,chemia1 
#hg        8,elements10 ,aristotelian1  
qualities of1 #bc        ,elephantinum1 
#ad        ,elixir1 #cb        ,eller1  
#id        ,empedokles1 #bc             
,erastius1 ,thomas1 #ea                 
,equivalent1 #abi          ,fx vini1    
#acg        ,fischer1 ,g4 ,e41 #abd     
,flos ris1 #ab        ,fourcroy1 #aab1  
#aah1 #aee1 #aeh1 #afa1 #afb            
,frankland1 #afh          ,gahn1 #ajh   
,gas sylvestre1 #fc        ,gay ,lussac1
 #aej1 #aee1 #afa1 #afd1 #afg1 #agh1    
#aha        ,geber1 #cf        theory of
 metals1 #cg1 #aef        ,generation of
 metals1 #cc        ,geoffroy1 #ajf     
,gerhardt1 #afh        ,glass1 known to 
the ancients1 #ae        ,glauber1      
,johann ,rudolf1 #fh        ,glucinum1  

its discovery1 #abj        ,gmelin1 ,l4 
#afa        ,gold1 extraction by        
ancients1 #g        ,goulard1 #aeg      
,gomes1 #afa        ,gttling1 #aef      
,graham1 ,thomas1 #agh        ,gresham  
,college1 #gd        ,gualdo1 #di       
,guyton de ,morveau1 #aab1 #afj         
,hmatinon1 #ae        ,hales1 ,stephen1 
#hi        8,harmonics10 ,paracelsian1  
#fa        ,hauy1 #agf        ,hellot1  
#ajh        ,helmont1 ,john ,baptist    
van1 #fc        ,helvetius1 #dh         
,hennel1 #aee        ,henry1 #aha       
,herakleitos1 #ba        ,here1 god of  
air1 #bb        ,hermbstdt1 #aeh        
,hermes ,trismegistus1 #d1 #cc          
8,hermes of ,germany1 the01 #eb         
,hoffmann1 #ajf        ,homberg1        
,william1 #hd                           
,houton-,labillardire1 #aeh             
,howard1 #afa        ,hyalos1 use of1   
for kindling fire1 #ae                  
,hydrargyrum1 #aa                       
,iatro-chemistry1 #eg        ,ink of the
 ancients1 #ad        ,ingenhousz1 #ba  

,invisible ,college1 the1 #gd           
,iron1 use of1 by the ancients1 #aj     
,irvine1 #agb        ,isaac of ,holland1
 #di        ,isomerism1 #afe            
,isomorphism1 discovery of1 #agf        
8,kalid10 his philosopher's stone1 #dh  
,key of ,wisdom1 #ec        ,kircher1   
#ea        ,kirchhoff1 #afb             
,kirwan1 #aac        ,klaproth1 #abj1   
#afj        ,klettenberg1 ,hector de1   
#ed        ,kopp1 #aha                  
,krohnemann1 ,william de1 #ec           
,kunkel1 ,john1 #ea1 #gi                
,laboratorium ,chymicum1 #hj        ,lac
 ,virginis1 #aeg        ,lagrange1 #aaf 
,laplace1 #agb        ,latent heat1 #ii1
 #agb        ,lauraquais1 #aee          
,laurent1 #afh        ,lavoisier1 #bj1  
#bb1 #aji        antiphlogistic theory1 
#aab1 #aaf1 #aef1 #afd1 #aff1 #agc      
,law of ,dulong and ,petit1 #agc1 #agd  
,law of electrolytic action1 #aec       
,lead1 known to the ancients1 #aj       
,leblanc1 #ajh        ,lehmann1 #aei    
,lemery1 ,nicolas1 #hc1 #aed1 #aef      

,leo ,africanus1 #cf        ,leukippos1 
#bf        ,libavius1 ,andreas 7,libau71
 #fb1 #aee1 #aeg        ,lieber1        
,thomas1 #fe        ,liebig1 #aee1 #aef1
 #aei1 #afd1 #afg        ,lwiz1 #aef    
,lucretius1 #bf1 #bg        ,lully1     
,raymund1 #da1 #dg1 #di                 
,macquer1 #ih        ,magistery1 grand1 
#dh        small1 #dh        ,magnesia  
alba1 nature of1 #ajg        ,manganese1
 discovery of1 #ajg        ,marggraf1   
#ie1 #ajg1 #ajh1 #aeg        ,marie     
,ziglerin burnt1 #ec        ,martian    
preparations1 #cg        ,marriotte1    
#agh        ,maternus1 ,julius          
,firmicus1 #ce        ,mayerne1 ,turquet
 de1 #fe        ,mayow1 ,john1 #hb et   
seq4        ,medicine and ,astrology1   
#eh        ,melinum1 #ac-ad             
,menethes ,sibonita1 #c                 
8,mercury10 as 8element01 #ca           
,mercury1 receipt for fixing1 #ej       
,metallurgy of the ancients1 #g         
,metals of the phlogistians1 #ajd       
,minderer1 ,raymond1 #aeg               

,minium1 #ab        ,mitscherlich1 #aei1
 #age1 #agf1 #agg        ,molybdena1 #ab
        ,monge1 #ahj        ,monro1     
,donald1 #aei        ,mordants1         
,egyptian1 #ae        ,mundamus1 #dc    
,mynsicht1 ,adrian van1 #fe1 #aeh       
,narcotine1 #afa        ,natron1 used as
 a detergent1 #af        ,natterer1 #ahj
        ,nestis1 god of water1 #bb      
,neumann1 #id1 #age        ,new ,system 
of ,chemical ,philosophy1 ,dalton's1    
#abi        ,nickel1 discovery of1 #ajg 
,nitrogen1 discovery of1 #ajg           
,northmore1 #ahj          rugo1 #ab     
,oil of wine1 #aee        ,okeanos1 #ai 
,oleus ,borrichius1 #cc                 
,olimpiodorus1 #ce        ,onychitis1   
#ab        ,operinus1 #fj               
,ostracitis1 #ab        ,oxides1        
metallic1 used by ancients to colour    
glass #ae        ,oxygen1 its discovery1
 #aje        influence of1 on chemistry1
 #aje          ,palissy1 ,bernard1 #fg  
,paracelsus1 #dj1 #dh1 #eg              
,paratonium1 #ac        ,pelletier1 #afb

        ,peligot1 #afb                  
,peripatetic philosophy1 influence on   
science1 #bd        ,petit1 ,alexis     
,therese1 #agc1 #age        ,pherekides1
 #ba        ,philosophia ,orientalis1   
#ch        ,philosopher's ,stone1 #cb1  
#df1 #di        ,philosophical egg1 #cc 
,phlogistonism1 #ie et seq4             
,phosphorus1 discovery of1 #hj1 #ajg    
,placitis1 #ab        ,platinum1        
discovery of1 #ajg        ,plato's      
doctrine of 8elements01 #bc             
,pliny1 #aef        ,plumbum album1 #aj 
nigrum1 #aj        ,pope ,john ,,xxii41 
alchemist1 #df        ,porret1 #afj     
,pott1 #id1 #ie1 #aei        ,price1    
,james of ,guildford1 #ed               
,priestley1 ,joseph1 #bj1 #bb        his
 life and work1 #ii et seq4             
,proust1 ,joseph ,louis1 #aba           
,purple of ,cassius1 #ha                
,purpurissum1 #ac          ,quintessence
 of philosophers1 #cb                   
,raquetaillade1 ,jean de1 #dc           
,realgar1 #ac        ,reaumur1 #ajh     

,rey1 #aaj        ,rhazes1 #ch          
,richter1 ,jeremiah ,benjamin1 #abd     
,ripley1 ,george1 #dc        ,robiquet1 
#afa1 #afg        ,roebuck1 #ajh        
,rom de ,l',isle1 #agf        ,rose1    
,gustav1 #agg        ,rosenkreutz1      
,christian1 #ee        ,rouelle1 #id1   
#ajf1 #aei        ,royal ,society1      
foundation of1 #gd        ,rubrica1 #ac 
,rupecissa1 ,johannes de1 #dc           
,saccharum plumbi quintessentiale1 #aeg 
,sala1 ,angelus1 #fe        ,sal        
,armoniacum1 #dd        ,sal            
,duplicatum1 #ha        ,sal mirabile1  
#fh        ,sandarach1 #ac              
,saturnine solutions1 #cg               
,savary1 #aee        ,sceptical         
,chemist1 ,the1 #gj        ,scheele1 #if
 et seq41 #ajg1 #aee1 #aeh1 #aei1 #afj1 
#aff        ,schroeder1 #aha            
,scoria ris1 #ab        ,sefstrm1 #ace  
,seguin1 #aei        ,seignette1 ,peter1
 #aeg        ,selenium1 its discovery1  
#ace        ,sennert1 ,daniel1 #fe      
,sertrner1 #afa        ,severinus1 #fa  

,silver1 known to the ancients1 #g      
,sinopis1 #ac        ,soap1 manufacture 
by ,gauls1 #ae        ,specific heat1   
discovery of1 #ii        ,spiritus      
igno-areus1 #hb        ,stahl1 ,george  
,ernst1 #ib1 #aef        ,stannum1 #aj  
,statical ,essays of ,hales1 #hi        
,statique ,chimique1 #aag               
,stephanus1 #ce        ,stibium1 #ac    
,stimmi1 #ac        ,strontia1 discovery
 of1 #ajg        ,suidas1 #cd           
8,sulphur10 as 8element01 #ca           
,sulzbach1 #aaj        ,sun worship1 #bb
        ,sylvius1 ,francis de le ,bo1   
#fd        ,syncellus1 #ce              
,tachenius1 #fi        ,tartarus1       
doctrine of1 #ei1 #aeg                  
,tellurium1 discovery of1 #aba          
,terra pinguis of ,becher1 #ib          
,tertiarium1 #aj        ,tertullian1 #ai
        ,thales of ,miletus1 #ai        
,thnard1 #aeb1 #afd                     
,theophrastus1 #aef        ,the         
,tincture1 #cb        ,thilorier1 #ahj  
,thomson1 ,thomas1 #abi        ,thorium1

 its discovery1 #ace                    
,thurneysser1 ,leonard1 #ec1 #fj        
,tin1 known to the ,egyptians1 #i       
,transmutation1 #bh1 #cj                
,trommsdorff1 #aeg        ,tubal ,cain  
7,tuval-,cain71 #g        ,turquet de   
,mayerne1 #aeh        ,tyrian purple1   
#ad          ,valentine1 ,basil1 #dc1   
#dg1 #di1 #aef        ,van ,helmont1    
#bj1 #dh1 #fc        ,vasa murrhina1 #ae
        ,vauquelin1 #aai1 #aee1 #aeh1   
#afa1 #afb        ,verdigris1 #ef       
,vincent de ,beauvais1 #ej        ,von  
,ittner1 #afj          ,wallis1 ,john1  
#gd        ,ward1 ,seth1 #gd            
8,white0 gold1 #g        ,wilcke1 #agb  
,willis1 ,thomas1 #fd1 #gd              
,whler1 #afa1 #afc1 #afg                
,wollaston1 #add1 #agf        ,woodward1
 #afj        ,wray1 #aei        ,wren1  
,christopher1 #gd          ,zacharias1  
,daniel1 #di        ,zozimus the        
,panopolite1 #d          ,transcriber's 
,notes      ,punctuation and spelling   
were made consistent when a predominant 

preference was found in this book2      
otherwise they were not changed4        
,simple typographical errors were       
corrected2 occasional unbalanced        
quotation marks retained4    ,ambiguous 
hyphens at the ends of lines were       
retained2 occurrences of  inconsistent  
hyphenation have not been changed4      
,index not checked for proper           
alphabetization or correct page         
references4    ,page #af3 8jeunesse     
d'ore0 was printed that way1 but should 
be  8jeunesse dore04    ,page #ahc3     
8,moyenge0 was printed that way1 but    
should be 8,moyen ge04