,,the ,,advance ,,of ,,science ,,in     
,,the ,,last ,,half-,,century  ,,by     
,t4,h4 ,,huxley1 ,f4,r4,s4  ,,new ,,york
  ,d4 ,,appleton ,,and ,,company  #ahhi 
,,the ,,advance ,,of ,,science ,,in     
,,the ,,last ,,half-,,century           
,sidenote3 ,recent industrial progress  
,the most obvious and the most          
distinctive features of the ,history of 
,civilisation1 during the last fifty    
years1 is the wonderful increase of     
industrial production by the application
 of machinery1 the improvement of old   
technical processes and the invention of
 new ones1 accompanied by an even more  
remarkable development of old and new   
means of locomotion and                 
intercommunication4 ,by this rapid and  
vast multiplication of the commodities  
and conveniences of existence1 the      
general standard of comfort has been    
raised1 the ravages of pestilence and   
famine have been checked1 and the       
natural obstacles1 which time and space 
offer to mutual intercourse1 have been  

reduced in a manner1 and to an extent1  
unknown to former ages4 ,the diminution 
or removal of local ignorance and       
prejudice1 the creation of common       
interests among the most widely         
separated peoples1 and the strengthening
 of the forces of the organisation of   
the commonwealth against those of       
political or social anarchy1 thus       
effected1 have exerted an influence on  
the present and future fortunes of      
mankind the full significance of which  
may be divined1 but cannot1 as yet1 be  
estimated at its full value4  ,sidenote3
 caused by the increase of physical     
science  ,this revolution--for it is    
nothing less--in the political and      
social aspects of modern civilisation   
has been preceded1 accompanied1 and in  
great measure caused1 by a less obvious1
 but no less marvellous1 increase of    
natural knowledge1 and especially of    
that part of it which is known as       
,physical ,science1 in consequence of   
the application of scientific method to 

the investigation of the phenomena of   
the material world4 ,not that the growth
 of physical science is an exclusive    
prerogative of the ,victorian age4 ,its 
present strength and volume merely      
indicate the highest level of a stream  
which took its rise1 alongside of the   
primal founts of ,philosophy1           
,literature1 and ,art1 in ancient       
,greece2 and1 after being dammed up for 
a thousand years1 once more began to    
flow three centuries ago4  ,sidenote3   
,greek and medival science4  ,it may be 
doubted if even-handed justice1 as free 
from fulsome panegyric as from captious 
depreciation1 has ever yet been dealt   
out to the sages of antiquity who1 for  
eight centuries1 from the time of       
,thales to that of ,galen1 toiled at the
 foundations of physical science4 ,but1 
without entering into the discussion of 
that large question1 it is certain that 
the labors of these early workers in the
 field of natural knowledge were brought
 to a standstill by the decay and       

disruption of the ,roman ,empire1 the   
consequent disorganisation of society1  
and the diversion of men's thoughts from
 sublunary matters to the problems of   
the supernatural world suggested by     
,christian dogma in the ,middle ,ages4  
,and1 notwithstanding sporadic attempts 
to recall men to the investigation of   
nature1 here and there1 it was not until
 the fifteenth and sixteenth centuries  
that physical science made a new start1 
founding itself1 at first1 altogether   
upon that which had been done by the    
,greeks4 ,indeed1 it must be admitted   
that the men of the ,renaissance1 though
 standing on the shoulders of the old   
philosophers1 were a long time before   
they saw as much as their forerunners   
had done4  ,the first serious attempts  
to carry further the unfinished work of 
,archimedes1 ,hipparchus1 and ,ptolemy1 
of ,aristotle and of ,galen1 naturally  
enough arose among the astronomers and  
the physicians4 ,for the imperious      
necessity of seeking some remedy for the

 physical ills of life had insured the  
preservation of more or less of the     
wisdom of ,hippocrates and his          
successors1 and1 by a happy conjunction 
of circumstances1 the ,jewish and the   
,arabian physicians and philosophers    
escaped many of the influences which1 at
 that time1 blighted natural knowledge  
in the ,christian world4 ,on the other  
hand1 the superstitious hopes and fears 
which afforded countenance to astrology 
and to alchemy also sheltered astronomy 
and the germs of chemistry4 ,whether for
 this1 or for some better reason1 the   
founders of the schools of the ,middle  
,ages included astronomy1 along with    
geometry1 arithmetic1 and music1 as one 
of the four branches of advanced        
education2 and1 in this respect1 it is  
only just to them to observe that they  
were far in advance of those who sit in 
their seats4 ,the school men considered 
no one to be properly educated unless he
 were acquainted with1 at any rate1 one 
branch of physical science4 ,we have    

not1 even yet1 reached that stage of    
enlightenment4  ,sidenote3 ,further     
advance after ,renaissance4  ,in the    
early decades of the seventeenth        
century1 the men of the ,renaissance    
could show that they had already put out
 to good interest the treasure          
bequeathed to them by the ,greeks4 ,they
 had produced the astronomical system of
 ,copernicus1 with ,kepler's great      
additions2 the astronomical discoveries 
and the physical investigations of      
,galileo2 the mechanics of ,stevinus and
 the ',de ,magnete' of ,gilbert2 the    
anatomy of the great ,french and        
,italian schools and the physiology of  
,harvey4 ,in ,italy1 which had succeeded
 ,greece in the hegemony of the         
scientific world1 the ,accademia dei    
,lyncei and sundry other such           
associations for the investigation of   
nature1 the models of all subsequent    
academies and scientific societies1 had 
been founded1 while the literary skill  
and biting wit of ,galileo had made the 

great scientific questions of the day   
not only intelligible1 but attractive1  
to the general public4  ,sidenote3      
,francis ,bacon4  ,in our own country1  
,francis ,bacon1 had essayed to sum up  
the past of physical science1 and to    
indicate the path which it must follow  
if its great destinies were to be       
fulfilled4 ,and though the attempt was  
just such a magnificent failure as might
 have been expected from a man of great 
endowments1 who was so singularly devoid
 of scientific insight that he could not
 understand the value of the work       
already achieved by the true            
instaurators of physical science2 yet   
the majestic eloquence and the fervid   
vaticinations of one who was conspicuous
 alike by the greatness of his rise and 
the depth of his fall1 drew the         
attention of all the world to the 'new  
birth of ,time4'  ,sidenote3 ,the defect
 of his method4  ,but it is not easy to 
discover satisfactory evidence that the 
',novum ,organum' had any direct        

beneficial influence on the advancement 
of natural knowledge4 ,no delusion is   
greater than the notion that method and 
industry can make up for lack of        
motherwit1 either in science or in      
practical life2 and it is strange that1 
with his knowledge of mankind1 ,bacon   
should have dreamed that his1 or any    
other1 'via inveniendi scientias' would 
'level men's wits' and leave little     
scope for that inborn capacity which is 
called genius4 ,as a matter of fact1    
,bacon's 'via' has proved hopelessly    
impracticable2 while the 'anticipation  
of nature' by the invention of          
hypotheses based on incomplete          
inductions1 which he specially condemns1
 has proved itself to be a most         
efficient1 indeed an indispensable1     
instrument of scientific progress4      
,finally1 that transcendental           
alchemy--the superinducement of new     
forms on matter--which ,bacon declares  
to be the supreme aim of science1 has   
been wholly ignored by those who have   

created the physical knowledge of the   
present day4  ,even the eloquent        
advocacy of the ,chancellor brought no  
unmixed good to physical science4 ,it   
was natural enough that the man who1 in 
his better moments1 took 'all knowledge 
for his patrimony1' but1 in his worse1  
sold that birthright for the mess of    
pottage of ,court favor and professional
 success1 for pomp and show1 should be  
led to attach an undue value to the     
practical advantages which he foresaw1  
as ,roger ,bacon and1 indeed1 ,seneca   
had foreseen1 long before his time1 must
 follow in the train of the advancement 
of natural knowledge4 ,the burden of    
,bacon's pleadings for science is the   
gathering of fruit'--the importance of  
winning solid material advantages by the
 investigation of ,nature and the       
desirableness of limiting the           
application of scientific methods of    
inquiry to that field4  ,sidenote3      
,hobbes4  ,sidenote3 ,descartes4        
,bacon's younger contemporary1 ,hobbes1 

casting aside the prudent reserve of his
 predecessor in regard to those matters 
about which the ,crown or the ,church   
might have something to say1 extended   
scientific methods of inquiry to the    
phenomena of mind and the problems of   
social organisation2 while1 at the same 
time1 he indicated the boundary between 
the province of real1 and that of       
imaginary1 knowledge4 ,the ',principles 
of ,philosophy' and the ',leviathan'    
embody a coherent system of purely      
scientific thought in language which is 
a model of clear and vigorous ,english  
style4 ,at the same time1 in ,france1 a 
man of far greater scientific capacity  
than either ,bacon or ,hobbes1 ,ren     
,descartes1 not only in his immortal    
',discours de la ,mthode' and elsewhere1
 went down to the foundations of        
scientific certainty1 but1 in his       
',principes de ,philosophie1' indicated 
where the goal of physical science      
really lay4 ,however1 ,descartes was an 
eminent mathematician1 and it would seem

 that the bent of his mind led him to   
overestimate the value of deductive     
reasoning from general principles1 as   
much as ,bacon had underestimated it4   
,the progress of physical science has   
been effected neither by ,baconians nor 
by ,cartesians1 as such1 but by men like
 ,galileo and ,harvey1 ,boyle and       
,newton1 who would have done their work 
just as well if neither ,bacon nor      
,descartes had ever propounded their    
views respecting the manner in which    
scientific investigation should be      
pursued4  ,sidenote3 ,for a time the    
progress without fruits4  ,the progress 
of science1 during the first century    
after ,bacon's death1 by means verified 
his sanguine prediction of the fruits   
which it would yield4 ,for1 though the  
revived and renewed study of nature had 
spread and grown to an extent which     
surpassed reasonable expectation1 the   
practical results--the 'good to men's   
estate'--were1 at first1 by no means    
apparent4 ,sixty years after ,bacon's   

death1 ,newton had crowned the long     
labors of the astronomers and the       
physicists1 by coordinating the         
phenomena of solar motion throughout the
 visible universe into one vast system2 
but the ',principia' helped no man to   
either wealth or comfort4 ,descartes1   
,newton1 and ,leibnitz had opened up new
 worlds to the mathematician1 but the   
acquisitions of their genius enriched   
only man's ideal estate4 ,descartes had 
laid the foundations of rational        
cosmogony and of physiological          
psychology2 ,boyle had produced models  
of experimentation in various branches  
of physics and chemistry2 ,pascal and   
,torricelli had weighed the air2        
,malpighi and ,grew1 ,ray and           
,willoughby had done work of no less    
importance in the biological sciences2  
but weaving and spinning were carried on
 with the old appliances2 nobody could  
travel faster by sea or by land than at 
any previous time in the world's        
history1 and ,king ,george could send a 

message from ,london to ,york no faster 
than ,king ,john might have done4       
,metals were worked from their ores by  
immemorial rule of thumb1 and the centre
 of the iron trade of these islands was 
still among the oak forests of ,sussex4 
,the utmost skill of our mechanicians   
did not get beyond the production of a  
coarse watch4  ,the middle of the       
eighteenth century is illustrated by a  
host of great names in                  
science--,english1 ,french1 ,german1 and
 ,italian--especially in the fields of  
chemistry1 geology1 and biology2 but    
this deepening and broadening of natural
 knowledge produced next to no immediate
 practical benefits4 ,even if1 at this  
time1 ,francis ,bacon could have        
returned to the scene of his greatness  
and of his littleness1 he must have     
regarded the philosophic world which    
praised and disregarded his precepts    
with great disfavor4 ,if ghosts are     
consistent1 he would have said1 ',these 
people are all wasting their time1 just 

as ,gilbert and ,kepler and ,galileo and
 my worthy physician ,harvey did in my  
day4 ,where are the fruits of the       
restoration of science which ,i         
promised8 ,this accumulation of bare    
knowledge is all very well1 but cui     
bono8 ,not one of these people is doing 
what ,i told him specially to do1 and   
seeking that secret of the cause of     
forms which will enable men to deal1 at 
will1 with matter1 and superinduce new  
natures upon the old foundations4'      
,sidenote3 ,its recent effect on life4  
,but1 a little later1 that growth of    
knowledge beyond imaginable utilitarian 
ends1 which is the condition precedent  
of its practical utility1 began to      
produce some effect upon practical life2
 and the operation of that part of      
nature we call human upon the rest began
 to create1 not 'new natures1' in       
,bacon's sense1 but a new ,nature1 the  
existence of which is dependent upon    
men's efforts1 which is subservient to  
their wants1 and which would disappear  

if man's shaping and guiding hand were  
withdrawn4 ,every mechanical artifice1  
every chemically pure substance employed
 in manufacture1 every abnormally       
fertile race of plants1 or rapidly      
growing and fattening breed of animals1 
is a part of the new ,nature created by 
science4 ,without it1 the most densely  
populated regions of modern ,europe and 
,america must retain their primitive1   
sparsely inhabited1 agricultural or     
pastoral condition2 it is the foundation
 of our wealth and the condition of our 
safety from submergence by another flood
 of barbarous hordes2 it is the bond    
which unites into a solid political     
whole1 regions larger than any empire of
 antiquity2 it secures us from the      
recurrence of the pestilences and       
famines of former times2 it is the      
source of endless comforts and          
conveniences1 which are not mere        
luxuries1 but conduce to physical and   
moral well-being4 ,during the last fifty
 years1 this new birth of time1 this new

 ,nature begotten by science upon fact1 
has pressed itself daily and hourly upon
 our attention1 and has worked miracles 
which have modified the whole fashion of
 our lives4  ,sidenote3 ,these results  
often too much regarded2  ,what wonder1 
then1 if these astonishing fruits of the
 tree of knowledge are too often        
regarded by both friends and enemies as 
the be-all and end-all of science8 ,what
 wonder if some eulogise1 and others    
revile1 the new philosophy for its      
utilitarian ends and its merely material
 triumphs8  ,sidenote3 for scientific   
research rarely directed to practical   
ends  ,in truth1 the new philosophy     
deserves neither the praise of its      
eulogists1 nor the blame of its         
slanderers4 ,as ,i have pointed out1 its
 disciples were guided by no search     
after practical fruits1 during the great
 period of its growth1 and it reached   
adolescence without being stimulated by 
any rewards of that nature4 ,the bare   
enumeration of the names of the men who 

were the great lights of science in the 
latter part of the eighteenth and the   
first decade of the nineteenth century1 
of ,herschel1 of ,laplace1 of ,young1 of
 ,fresnel1 of ,oersted1 of ,cavendish1  
of ,lavoisier1 of ,davy1 of ,lamarck1 of
 ,cuvier1 of ,jussieu1 of ,decandolle1  
of ,werner and of ,hutton1 suffices to  
indicate the strength of physical       
science in the age immediately preceding
 that of which ,i have to treat4 ,but of
 which of these great men can it be said
 that their labors were directed to     
practical ends8 ,i do not call to mind  
even an invention of practical utility  
which we owe to any of them1 except the 
safety lamp of ,davy4 ,werner certainly 
paid attention to mining1 and ,i have   
not forgotten ,james ,watt4 ,but1 though
 some of the most important of the      
improvements by which ,watt converted   
the steam-engine1 invented long before  
his time1 into the obedient slave of    
man1 were suggested and guided by his   
acquaintance with scientific principles1

 his skill as a practical mechanician1  
and the efficiency of ,bolton's workmen 
had quite as much to do with the        
realisation of his projects4  ,sidenote3
 but instigated by love of knowledge    
,in fact1 the history of physical       
science teaches 7and we cannot too      
carefully take the lesson to heart7 that
 the practical advantages1 attainable   
through its agency1 never have been1 and
 never will be1 sufficiently attractive 
to men inspired by the inborn genius of 
the interpreter of nature1 to give them 
courage to undergo the toils and make   
the sacrifices which that calling       
requires from its votaries4 ,that which 
stirs their pulses is the love of       
knowledge and the joy of the discovery  
of the causes of things sung by the old 
poets--the supreme delight of extending 
the realm of law and order ever farther 
towards the unattainable goals of the   
infinitely great and the infinitely     
small1 between which our little race of 
life is run4 ,in the course of this     

work1 the physical philosopher1         
sometimes intentionally1 much more often
 unintentionally1 lights upon something 
which proves to be of practical value4  
,great is the rejoicing of those who are
 benefited thereby2 and1 for the moment1
 science is the ,diana of all the       
craftsmen4 ,but1 even while the cries of
 jubilation resound and this floatsam   
and jetsam of the tide of investigation 
is being turned into the wages of       
workmen and the wealth of capitalists1  
the crest of the wave of scientific     
investigation is far away on its course 
over the illimitable ocean of the       
unknown4  ,sidenote3 ,it is in its turn 
assisted by industrial improvements4    
,far be it from me to depreciate the    
value of the gifts of science to        
practical life1 or to cast a doubt upon 
the propriety of the course of action of
 those who follow science in the hope of
 finding wealth alongside truth1 or even
 wealth alone4 ,such a profession is as 
respectable as any other4 ,and quite as 

little do ,i desire to ignore the fact  
that1 if industry owes a heavy debt to  
science1 it has largely repaid the loan 
by the important aid which it has1 in   
its turn1 rendered to the advancement of
 science4 ,in considering the causes    
which hindered the progress of physical 
knowledge in the schools of ,athens and 
of ,alexandria1 it has often struck me,a
 that where the ,greeks did wonders was 
in just those branches of science1 such 
as geometry1 astronomy1 and anatomy1    
which are susceptible of very           
considerable development without any1 or
 any but the simplest1 appliances4 ,it  
is a curious speculation to think what  
would have become of modern physical    
science if glass and alcohol had not    
been easily obtainable2 and if the      
gradual perfection of mechanical skill  
for industrial ends had not enabled     
investigators to obtain1 at             
comparatively little cost1 microscopes1 
telescopes1 and all the exquisitely     
delicate apparatus for determining      

weight and measure and for estimating   
the lapse of time with exactness1 which 
they now command4 ,if science has       
rendered the colossal development of    
modern industry possible1 beyond a doubt
 industry has done no less for modern   
physics and chemistry1 and for a great  
deal of modern biology4 ,and as the     
captains of industry have1 at last1     
begun to be aware that the condition of 
success in that warfare1 under the forms
 of peace1 which is known as industrial 
competition lies in the discipline of   
the troops and the use of arms of       
precision1 just as much as it does in   
the warfare which is called war1 their  
demand for that discipline1 which is    
technical education1 is reacting upon   
science in a manner which will1         
assuredly1 stimulate its future growth  
to an incalculable extent4 ,it has      
become obvious that the interests of    
science and of industry are identical1  
that science cannot make a step forward 
without1 sooner or later1 opening up new

 channels for industry1 and1 on the     
other hand1 that every advance of       
industry facilitates those experimental 
investigations1 upon which the growth of
 science depends4 ,we may hope that1 at 
last1 the weary misunderstanding between
 the practical men who professed to     
despise science1 and the high and dry   
philosophers who professed to despise   
practical results1 is at an end4        
,nevertheless1 that which is true of the
 infancy of physical science in the     
,greek world1 that which is true of its 
adolescence in the seventeenth and      
eighteenth centuries1 remains true of   
its riper age in these latter days of   
the nineteenth century4 ,the great steps
 in its progress have been made1 are    
made1 and will be made1 by men who seek 
knowledge simply because they crave for 
it4 ,they have their weaknesses1 their  
follies1 their vanities1 and their      
rivalries1 like the rest of the world2  
but whatever by-ends may mar their      
dignity and impede their usefulness1    

this chief end redeems them4,b ,nothing 
great in science has ever been done by  
men1 whatever their powers1 in whom the 
divine afflatus of the truth-seeker was 
wanting4 ,men of moderate capacity have 
done great things because it animated   
them2 and men of great natural gifts    
have failed1 absolutely or relatively1  
because they lacked this one thing      
needful4  ,sidenote3 ,true aim and      
method of research4  ,to anyone who     
knows the business of investigation     
practically1 ,bacon's notion of         
establishing a company of investigators 
to work for 'fruits1' as if the pursuit 
of knowledge were a kind of mining      
operation and only required             
well-directed picks and shovels1 seems  
very strange4,c ,in science1 as in art1 
and1 as ,i believe1 in every other      
sphere of human activity1 there may be  
wisdom in a multitude of counsellors1   
but it is only in one or two of them4   
,and1 in scientific inquiry1 at any     
rate1 it is to that one or two that we  

must look for light and guidance4       
,newton said that he made his           
discoveries by 'intending' his mind on  
the subject2 no doubt truly4 ,but to    
equal his success one must have the mind
 which he 'intended4' ,forty lesser men 
might have intended their minds till    
they cracked1 without any like result4  
,it would be idle either to affirm or to
 deny that the last half-century has    
produced men of science of the calibre  
of ,newton4 ,it is sufficient that it   
can show a few capacities of the first  
rank1 competent not only to deal        
profitably with the inheritance         
bequeathed by their scientific          
forefathers1 but to pass on to their    
successors physical truths of a higher  
order than any yet reached by the human 
race4 ,and if they have succeeded as    
,newton succeeded1 it is because they   
have sought truth as he sought it1 with 
no other object than the finding it4    
99       99       99       99       99  
,sidenote3 ,progress from #ahcg to      

#ahhg4  ,i am conscious that in         
undertaking to progress give even the   
briefest sketch of the progress of      
physical science1 in all its branches1  
during the last half-century1 ,i may be 
thought to have exhibited more courage  
than discretion1 and perhaps more       
presumption than either4 ,so far as     
physical science is concerned1 the days 
of ,admirable ,crichtons have long been 
over1 and the most indefatigable of hard
 workers may think he has done well if  
he has mastered one of its minor        
subdivisions4 ,nevertheless1 it is      
possible for anyone1 who has            
familiarised himself with the operations
 of science in one department1 to       
comprehend the significance1 and even to
 form a general estimate of the value1  
of the achievements of specialists in   
other departments4  ,nor is their any   
lack either of guidance1 or of aids to  
ignorance4 ,by a happy chance1 the first
 edition of ,whewell's ',history of the 
,inductive ,sciences' was published in  

#ahcg1 and it affords a very useful view
 of the state of things at the          
commencement of the ,victorian epoch4   
,as to subsequent events1 there are     
numerous excellent summaries of the     
progress of various branches of science1
 especially up to #ahha1 which was the  
jubilee year of the ,british            
,association4,d ,and1 with respect to   
the biological sciences1 with some parts
 of which my studies have familiarised  
me1 my personal experience nearly       
coincides with the preceding            
half-century4 ,i may hope1 therefore1   
that my chance of escaping serious      
errors is as good as that of anyone     
else1 who might have been persuaded to  
undertake the somewhat perilous         
enterprise in which ,i find myself      
engaged4  ,there is yet another         
prefatory remark which it seems         
desirable ,i should make4 ,it is that ,i
 think it proper to confine myself to   
the work done1 without saying anything  
about the doers of it4 ,meddling with   

questions of merit and priority is a    
thorny business at the best of times1   
and unless in case of necessity1        
altogether undesirable when one is      
dealing with contemporaries4 ,no such   
necessity lies upon me1 and ,i shall1   
therefore1 mention no names of living   
men1 lest1 perchance1 ,i should incur   
the reproof which the ,israelites1 who  
struggled with one another in the field1
 addressed to ,moses--',who made thee a 
prince and a judge over us4'  ,sidenote3
 ,the aim of physical science  ,physical
 science is one and indivisible4        
,although1 for practical purposes1 it is
 convenient to mark it out into the     
primary regions of ,physics1 ,chemistry1
 and ,biology1 and to subdivide these   
into subordinate provinces1 yet the     
method of investigation and the ultimate
 object of the physical inquirer are    
everywhere the same4  ,sidenote3 the    
discovery of the rational order of the  
universe  ,the object is the discovery  
of the rational order which pervades the

 universe1 the method consists of       
observation and experiment 7which is    
observation under artificial conditions7
 for the determination of the facts of  
nature1 of inductive and deductive      
reasoning for the discovery of their    
mutual relations and connection4 ,the   
various branches of physical science    
differ in the extent to which at any    
given moment of their history1          
observation on the one hand1 or         
ratiocination on the other1 is their    
more obvious feature1 but in no other   
way1 and nothing can be more incorrect  
than the assumption one sometimes meets 
with1 that physics has one method1      
chemistry another1 and biology a third4 
,sidenote3 ,it is based on postulates   
,all physical science starts from       
certain postulates4 ,one of them is the 
objective existence of a material world4
 ,it is assumed that the phenomena which
 are comprehended under this name have a
 'substratum' of extended1 impenetrable1
 mobile substance1 which exhibits the   

quality known as inertia1 and is termed 
matter4,e ,another postulate is the     
universality of the law of causation2   
that nothing happens without a cause    
7that is1 a necessary precedent         
condition71 and that the state of the   
physical universe1 at any given moment1 
is the consequence of its state at any  
preceding moment4 ,another is that any  
of the rules1 or so-called 'laws of     
nature1' by which the relation of       
phenomena is truly defined1 is true for 
all time4 ,the validity of these        
postulates is a problem of metaphysics2 
they are neither self-evident nor are   
they1 strictly speaking1 demonstrable4  
,the justification of their employment1 
as axioms of physical philosophy1 lies  
in the circumstance that expectations   
logically based upon them are verified1 
or1 at any rate1 not contradicted1      
whenever they can be tested by          
experience4  ,sidenote3 and uses        
hypotheses4  ,physical science therefore
 rests on verified or uncontradicted    

hypotheses2 and1 such being the case1 it
 is not surprising that a great         
condition of its progress has been the  
invention of verifiable hypotheses4 ,it 
is a favorite popular delusion that the 
scientific inquirer is under a sort of  
moral obligation to abstain from going  
beyond that generalisation of observed  
facts which is absurdly called          
',baconian' induction4 ,but anyone who  
is practically acquainted with          
scientific work is aware that those who 
refuse to go beyond fact1 rarely get as 
far as fact2 and anyone who has studied 
the history of science knows that almost
 every great step therein has been made 
by the 'anticipation of ,nature1' that  
is1 by the invention of hypotheses1     
which1 though verifiable1 often had very
 little foundation to start with2 and1  
not unfrequently1 in spite of a long    
career of usefulness1 turned out to be  
wholly erroneous in the long run4       
,sidenote3 ,fruitful use of an          
hypothesis even when wrong4  ,the       

geocentric system of astronomy1 with its
 eccentrics and its epicycles1 was an   
hypothesis utterly at variance with     
fact1 which nevertheless did great      
things for the advancement of           
astronomical knowledge4 ,kepler was the 
wildest of guessers4 ,newton's          
corpuscular theory of light was of much 
temporary use in optics1 though nobody  
now believes in it2 and the undulatory  
theory1 which has superseded the        
corpuscular theory and has proved one of
 the most fertile of instruments of     
research1 is based on the hypothesis of 
the existence of an 'ether1' the        
properties of which are defined in      
propositions1 some of which1 to ordinary
 apprehension1 seem physical antinomies4
  ,it sounds paradoxical to say that the
 attainment of scientific truth has been
 effected1 to a great extent1 by the    
help of scientific errors4 ,but the     
subject-matter of physical science is   
furnished by observation1 which cannot  
extend beyond the limits of our         

faculties2 while1 even within those     
limits1 we cannot be certain that any   
observation is absolutely exact and     
exhaustive4 ,hence it follows that any  
given generalisation from observation   
may be true1 within the limits of our   
powers of observation at a given time1  
and yet turn out to be untrue1 when     
those powers of observation are directly
 or indirectly enlarged4 ,or1 to put the
 matter in another way1 a doctrine which
 is untrue absolutely1 may1 to a very   
great extent1 be susceptible of an      
interpretation in accordance with the   
truth4 ,at a certain period in the      
history of astronomical science1 the    
assumption that the planets move in     
circles was true enough to serve the    
purpose of correlating such observations
 as were then possible2 after ,kepler1  
the assumption that they move in        
ellipses became true enough in regard to
 the state of observational astronomy at
 that time4 ,we say still that the      
orbits of the planets are ellipses1     

because1 for all ordinary purposes1 that
 is a sufficiently near approximation to
 the truth2 but1 as a matter of fact1   
the centre of gravity of a planet       
describes neither an ellipse or any     
other simple curve1 but an immensely    
complicated undulating line4 ,it may    
fairly be doubted whether any           
generalisation1 or hypothesis1 based    
upon physical data is absolutely true1  
in the sense that a mathematical        
proposition is so2 but1 if its errors   
can become apparent only outside the    
limits of practicable observation1 it   
may be just as usefully adopted for one 
of the symbols of that algebra by which 
we interpret nature1 as if it were      
absolutely true4  ,the development of   
every branch of physical knowledge      
presents three stages which1 in their   
logical relation1 are successive4 ,the  
first is the determination of the       
sensible character and order of the     
phenomena4 ,this is ,natural ,history1  
in the original sense of the term1 and  

here nothing but observation and        
experiment avail us4 ,the second is the 
determination of the constant relations 
of the phenomena thus defined1 and their
 expression in rules or laws4 ,the third
 is the explication of these particular 
laws by deduction from the most general 
laws of matter and motion4 ,the last two
 stages constitute ,natural ,philosophy 
in its original sense4 ,in this region1 
the invention of verifiable hypotheses  
is not only permissible1 but is one of  
the conditions of progress4  ,sidenote3 
and mutual assistance of observation1   
experiment1 and speculation4            
,historically1 no branch of science has 
followed this order of growth2 but1 from
 the dawn of exact knowledge to the     
present day1 observation1 experiment1   
and speculation have gone hand in hand2 
and1 whenever science has halted or     
strayed from the right path1 it has     
been1 either because its votaries have  
been content with mere unverified or    
unverifiable speculation 7and this is   

the commonest case1 because observation 
and experiment are hard work1 while     
speculation is amusing72 or it has been1
 because the accumulation of details of 
observation has for a time excluded     
speculation4  ,sidenote3 ,recognition of
 these truths in recent times1 and      
consequent progress4  ,the progress of  
physical science1 since the revival of  
learning1 is largely due to the fact    
that men have gradually learned to lay  
aside the consideration of unverifiable 
hypotheses2 to guide observation and    
experiment by verifiable hypotheses2 and
 to consider the latter1 not as ideal   
truths1 the real entities of an         
intelligible world behind phenomena1 but
 as a symbolical language1 by the aid of
 which nature can be interpreted in     
terms apprehensible by our intellects4  
,and if physical science1 during the    
last fifty years1 has attained          
dimensions beyond all former precedent1 
and can exhibit achievements of greater 
importance than any former such period  

can show1 it is because able men1       
animated by the true scientific spirit1 
carefully trained in the method of      
science1 and having at their disposal   
immensely improved appliances1 have     
devoted themselves to the enlargement of
 the boundaries of natural knowledge in 
greater number than during any previous 
half-century of the world's history4    
,sidenote3 ,the three great             
achievements4 ,doctrines of 7#a7        
molecular constitution of matter1 7#b7  
conservation of energy1 7#c7 evolution4 
,i have said that our epoch can produce 
achievements in physical science of     
greater moment than any other has to    
show1 advisedly2 and ,i think that there
 are three great products of our time   
which justify the assertion4 ,one of    
these is that doctrine concerning the   
constitution of matter which1 for want  
of a better name1 ,i will call          
'molecular2' the second is the doctrine 
of conservation of energy2 the third is 
the doctrine of evolution4 ,each of     

these was foreshadowed1 more or less    
distinctly1 in former periods of the    
history of science2 and1 so far is      
either from being the outcome of purely 
inductive reasoning1 that it would be   
hard to overrate the influence of       
metaphysical1 and even of theological1  
considerations upon the development of  
all three4 ,the peculiar merit of our   
epoch is that it has shown how these    
hypotheses connect a vast number of     
seemingly independent partial           
generalisations2 that it has given them 
that precision of expression which is   
necessary for their exact verification2 
and that it has practically proved their
 value as guides to the discovery of new
 truth4 ,all three doctrines are        
intimately connected1 and each is       
applicable to the whole physical cosmos4
 ,but1 as might have been expected from 
the nature of the case1 the first two   
grew1 mainly1 out of the consideration  
of physico-chemical phenomena2 while the
 third1 in great measure1 owes its      

rehabilitation1 if not its origin1 to   
the study of biological phenomena4      
,sidenote3 7#a7 ,molecular constitution 
of matter4  ,in the early decades of    
this century1 a number of important     
truths applicable1 in part1 to matter in
 general1 and1 in part1 to particular   
forms of matter1 had been ascertained by
 the physicists and chemists4  ,the laws
 of motion of visible and tangible1 or  
molar1 matter had been worked out to a  
great degree of refinement and embodied 
in the branches of science known as     
,mechanics1 ,hydrostatics1 and          
,pneumatics4 ,these laws had been shown 
to hold good1 so far as they could be   
checked by observation and experiment1  
throughout the universe1 on the         
assumption that all such masses of      
matter possessed inertia and were       
susceptible of acquiring motion1 in two 
ways1 firstly by impact1 or impulse from
 without2 and1 secondly1 by the         
operation of certain hypothetical causes
 of motion termed 'forces1' which were  

usually supposed to be resident in the  
particles of the masses themselves1 and 
to operate at a distance1 in such a way 
as to tend to draw any two such masses  
together1 or to separate them more      
widely4  ,sidenote3 ,the two theories as
 to matter4  ,with respect to the       
ultimate constitution of these masses1  
the same two antagonistic opinions which
 had existed since the time of          
,democritus and of ,aristotle were still
 face to face4 ,according to the one1   
matter was discontinuous and consisted  
of minute indivisible particles or      
atoms1 separated by a universal vacuum2 
according to the other1 it was          
continuous1 and the finest              
distinguishable1 or imaginable1         
particles were scattered through the    
attenuated general substance of the     
plenum4 ,a rough analogy to the latter  
case would be afforded by granules of   
ice diffused through water2 to the      
former1 such granules diffused through  
absolutely empty space4  ,sidenote3     

,reassertion by ,dalton of atomic       
theory4  ,in the latter part of the     
eighteenth century1 the chemists had    
arrived at several very important       
generalisations respecting those        
properties of matter with which they    
were especially concerned4 ,however     
plainly ponderable matter seemed to be  
originated and destroyed in their       
operations1 they proved that1 as mass or
 body1 it remained indestructible and   
ingenerable2 and that1 so far1 it varied
 only in its perceptibility by our      
senses4 ,the course of investigation    
further proved that a certain number of 
the chemically separable kinds of matter
 were unalterable by any known means    
7except in so far as they might be made 
to change their state from solid to     
fluid1 or vice vers71 unless they were  
brought into contact with other kinds of
 matter1 and that the properties of     
these several kinds of matter were      
always the same1 whatever their origin4 
,all other bodies were found to consist 

of two or more of these1 which thus took
 the place of the four 'elements' of the
 ancient philosophers4 ,further1 it was 
proved that1 in forming chemical        
compounds1 bodies always unite in a     
definite proportion by weight1 or in    
simple multiples of that proportion1 and
 that1 if any one body were taken as a  
standard1 every other could have a      
number assigned to it as its            
proportional combining weight4 ,it was  
on this foundation of fact that ,dalton 
based his re-establishment of the old   
atomic hypothesis on a new empirical    
foundation4 ,it is obvious1 that if     
elementary matter consists of           
indestructible and indivisible          
particles1 each of which constantly     
preserves the same weight relatively to 
all the others1 compounds formed by the 
aggregation of two1 three1 four1 or more
 such particles must exemplify the rule 
of combination in definite proportions  
deduced from observation4  ,in the      
meanwhile1 the gradual reception of the 

undulatory theory of light necessitated 
the assumption of the existence of an   
'ether' filling all space4 ,but whether 
this ether was to be regarded as a      
strictly material and continuous        
substance was an undecided point1 and   
hence the revived atomism1 escaped      
strangling in its birth4 ,for it is     
clear1 that if the ether is admitted to 
be a continuous material substance1     
,democritic atomism is at an end and    
,cartesian continuity takes its place4  
,sidenote3 ,the real value of           
hypothesis2 it predicates the existence 
of units of matter4  ,the real value of 
the new atomic hypothesis1 however1 did 
not lie in the two points which         
,democritus and his followers would have
 considered essential--namely1 the      
indivisibility of the 'atoms' and the   
presence of an interatomic vacuum--but  
in the assumption that1 to the extent to
 which our means of analysis take us1   
material bodies consist of definite     
minute masses1 each of which1 so far as 

physical and chemical processes of      
division go1 may be regarded as a       
unit--having a practically permanent    
individuality4 ,just as a man is the    
unit of sociology1 without reference to 
the actual fact of his divisibility1 so 
such a minute mass is the unit of       
physico-chemical science--that smallest 
material particle which under any given 
circumstances acts as a whole4,f  ,the  
doctrine of specific heat originated in 
the eighteenth century4 ,it means that  
the same mass of a body1 under the same 
circumstances1 always requires the same 
quantity of heat to raise it to a given 
temperature1 but that equal masses of   
different bodies require different      
quantities4 ,ultimately1 it was found   
that the quantities of heat required to 
raise equal masses of the more perfect  
gases1 through equal ranges of          
temperature1 were inversely proportional
 to their combining weights4 ,thus a    
definite relation was established       
between the hypothetical units and heat4

 ,the phenomena of electrolytic         
decomposition showed that there was a   
like close relation between these units 
and electricity4 ,the quantity of       
electricity generated by the combination
 of any two units is sufficient to      
separate any other two which are        
susceptible of such decomposition4 ,the 
phenomena of isomorphism showed a       
relation between the units and          
crystalline forms2 certain units are    
thus able to replace others in a        
crystalline body without altering its   
form1 and others are not4  ,again1 the  
laws of the effect of pressure and heat 
on gaseous bodies1 the fact that they   
combine in definite proportions by      
volume1 and that such proportion bears a
 simple relation to their combining     
weights1 all harmonised with the        
,daltonian hypothesis1 and led to the   
bold speculation known as the law of    
,avogadro--that all gaseous bodies1     
under the same physical conditions1     
contain the same number of units4 ,in   

the form in which it was first          
enunciated1 this hypothesis was         
incorrect--perhaps it is not exactly    
true in any form2 but it is hardly too  
much to say that chemistry and molecular
 physics would never have advanced to   
their present condition unless it had   
been assumed to be true4 ,another       
immense service rendered by ,dalton1 as 
a corollary of the new atomic doctrine1 
was the creation of a system of symbolic
 notation1 which not only made the      
nature of chemical compounds and        
processes easily intelligible and easy  
of recollection1 but1 by its very form1 
suggested new lines of inquiry4 ,the    
atomic notation was as serviceable to   
chemistry as the binomial nomenclature  
and the classificatory schematism of    
,linnus were to zology and botany4      
,sidenote3 ,in biology a like theory of 
molecularstructure4  ,side by side with 
these advances arose in another1 which  
also has a close parallel in the history
 of biological science4 ,if the unit of 

a compound is made up by the aggregation
 of elementary units1 the notion that   
these must have some sort of definite   
arrangement inevitably suggests itself2 
and such phenomena as double            
decomposition pointed1 not only to the  
existence of a molecular architecture1  
but to the possibility of modifying a   
molecular fabric without destroying it1 
by taking out some of the component     
units and replacing them by others4 ,the
 class of neutral salts1 for example1   
includes a great number of bodies in    
many ways similar1 in which the basic   
molecules1 or the acid molecules1 may be
 replaced by other basic and other acid 
molecules without altering the          
neutrality of the salt2 just as a cube  
of bricks remains a cube1 so long as any
 brick that is taken out is replaced by 
another of the same shape and           
dimensions1 whatever its weight or other
 properties may be4 ,facts of this kind 
gave rise to the conception of 'types'  
of molecular structure1 just as the     

recognition of the unity in diversity of
 the structure of the species of plants 
and animals gave rise to the notion of  
biological 'types4' ,the notation of    
chemistry enabled these ideas to be     
represented with precision2 and they    
acquired an immense importance1 when the
 improvement of methods of analysis1    
which took place about the beginning of 
our period1 enabled the composition of  
the so-called 'organic' bodies to be    
determined with1 rapidity and           
precision4,g ,a large proportion of     
these compounds contain not more than   
three or four elements1 of which carbon 
is the chief2 but their number is very  
great1 and the diversity of their       
physical and chemical properties is     
astonishing4 ,the ascertainment of the  
proportion of each element in these     
compounds affords little or no help     
towards accounting for their            
diversities2 widely different bodies    
being often very similar1 or even       
identical1 in that respect4 ,and1 in the

 last case1 that of isomeric compounds1 
the appeal to diversity of arrangement  
of the identical component units was the
 only obvious way out of the difficulty4
 ,here1 again1 hypothesis proved to be  
of great value2 not only was the search 
for evidence of diversity of molecular  
structure successful1 but the study of  
the process of taking to pieces led to  
the discovery of the way to put         
together2 and vast numbers of compounds1
 some of them previously known only as  
products of the living economy1 have    
thus been artificially constructed4     
,chemical work1 at the present day1 is1 
to a large extent1 synthetic or         
creative--that is to say1 the chemist   
determines1 theoretically1 that certain 
non-existent compounds ought to be      
producible1 and he proceeds to produce  
them4  ,it is largely because the       
chemical theory and practice of our     
epoch have passed into this deductive   
and synthetic stage1 that they are      
entitled to the name of the ',new       

,chemistry' which they commonly receive4
 ,but this new chemistry has grown up by
 the help of hypotheses1 such as those  
of ,dalton and of ,avogadro1 and that   
singular conception of 'bonds' invented 
to colligate the facts of 'valency' or  
'atomicity1' the first of which took    
some time to make its way2 while the    
second fell into oblivion1 for many     
years after it was propounded1 for lack 
of empirical justification4 ,as for the 
third1 it may be doubted if anyone      
regards it as more than a temporary     
contrivance4  ,but some of these        
hypotheses have done yet further        
service4 ,combining them with the       
mechanical theory of heat and the       
doctrine of the conservation of energy1 
which are also products of our time1    
physicists have arrived at an entirely  
new conception of the nature of gaseous 
bodies and of the relation of the       
physico-chemical units of matter to the 
different forms of energy4 ,the conduct 
of gases under varying pressure and     

temperature1 their diffusibility1 their 
relation to radiant heat and to light1  
the evolution of heat when bodies       
combine1 the absorption of heat when    
they are dissociated1 and a host of     
other molecular phenomena1 have been    
shown to be deducible from the dynamical
 and statical principles which apply to 
molar motion and rest2 and the tendency 
of physico-chemical science is clearly  
towards the reduction of the problems of
 the world of the infinitely little1 as 
it already has reduced those of the     
infinitely great world1 to questions of 
mechanics4,h  ,in the meanwhile1 the    
primitive atomic theory1 which has      
served as the scaffolding for the       
edifice of modern physics and chemistry1
 has been quietly dismissed4 ,i cannot  
discover that any contemporary physicist
 or chemist believes in the real        
indivisibility of atoms1 or in an       
interatomic matterless vacuum4 ',atoms' 
appear to be used as mere names for     
physico-chemical units which have not   

yet been subdivided1 and 'molecules' for
 physico-chemical units which are       
aggregates of the former4 ,and these    
individualised particles are supposed to
 move in an endless ocean of a vastly   
more subtle matter--the ether4 ,if this 
ether is a continuous substance1        
therefore1 we have got back from the    
hypothesis of ,dalton to that of        
,descartes4 ,but there is much reason to
 believe that science is going to make a
 still further journey1 and1 in form1 if
 not altogether in substance1 to return 
to the point of view of ,aristotle4     
,sidenote3 ,elementary bodies  ,the     
greater number of the so-called         
'elementary' bodies1 now known1 had been
 discovered before the commencement of  
our epoch2 and it had become apparent   
that they were by no means equally      
similar or dissimilar1 but that some of 
them1 at any rate1 constituted groups1  
the several members of which were as    
much like one another as they were      
unlike the rest4 ,chlorine1 iodine1     

bromine1 and fluorine thus formed a very
 distinct group2 sulphur and selenium   
another2 boron and silicon another2     
potassium1 sodium1 and lithium another2 
and so on4 ,in some cases1 the atomic   
weights of such allied bodies were      
nearly the same1 or could be arranged in
 series1 with like differences between  
the several terms4 ,in fact1 the        
elements afforded indications that they 
were susceptible of a classification in 
natural groups1 such as those into which
 animals and plants fall4  ,sidenote3   
fall into different series4  ,recently  
this subject has been taken up afresh1  
with a result which may be stated       
roughly in the following terms3 ,if the 
sixty-five or sixty-eight recognised    
'elements' are arranged in the order of 
their atomic weights--from hydrogen1 the
 lightest1 as unity1 to uranium1 the    
heaviest1 as #bdj--the series does not  
exhibit one continuous progressive      
modification in the physical and        
chemical characters of its several      

terms1 but breaks up into a number of   
sections1 in each of which the several  
terms present analogies with the        
corresponding terms of the other series4
  ,thus the whole series does not run3  
a1 b1 d1 e1 f1 g1 h1 i1 k1 c41  but  a1 
b1 c1 d1 ,a1 ,b1 ,c1 ,d1 alpha1 beta1   
gamma1 delta1 c42  so that it is said to
 express a periodic law of recurrent    
similarities4 ,or the relation may be   
expressed in another way4 ,in each      
section of the series1 the atomic weight
 is greater than in the preceding       
section1 so that if w is the atomic     
weight of any element in the first      
segment1 wx will represent the atomic   
weight of any element in the next1 and  
wxy the atomic weight of any element in 
the next1 and so on4 ,therefore the     
sections may be represented as parallel 
series1 the corresponding terms of which
 have analogous properties2 each        
successive series starting with a body  
the atomic weight of which is greater   
than that of any in the preceding       

series1 in the following fashion3  d    
,d         delta c       ,c             
gamma b       ,b          beta a        
,a         alpha  -      -----          
--------- w    w  x   w  x  y           
,sidenote3 ,the possibility of a primary
 form of matter4  ,this is a conception 
with1 which biologists are very         
familiar1 animal and plant groups       
constantly appearing as series of       
parallel modifications of similar and   
yet different primary forms4 ,in the    
living world1 facts of this kind are now
 understood to mean evolution from a    
common prototype4 ,it is difficult to   
imagine that in the not-living world    
they are devoid of significance4 ,is it 
not possible1 nay probable that they may
 mean the evolution of our 'elements'   
from a primary undifferentiated form of 
matter8 ,fifty years ago1 such a        
suggestion would have been scouted as a 
revival of the dreams of the alchemists4
 ,at present1 it may be said to be the  
burning question of physico-chemical    

science4  ,in fact1 the so-called       
'vortex-ring' hypothesis is a very      
serious and remarkable attempt to deal  
with material units from a point of view
 which is consistent with the doctrine  
of evolution4 ,it supposes the ether to 
be a uniform substance1 and that the    
'elementary' units are1 broadly         
speaking1 permanent whirlpools1 or      
vortices1 of this ether1 the properties 
of which depend on their actual and     
potential modes of motion4 ,it is       
curious and highly interesting to remark
 that this hypothesis reminds us not    
only of the speculations of ,descartes1 
but of those of ,aristotle4 ,the        
resemblance of the 'vortex-rings' to the
 'tourbillons' of ,descartes is little  
more than nominal2 but the              
correspondence between the modern and   
the ancient notion of a distinction     
between primary and derivative matter   
is1 to a certain extent1 real4 ,for this
 ethereal ',urstoff' of the modern      
corresponds very closely with the prht  

hyl of ,aristotle1 the materia prima of 
his medival followers2 while matter1    
differentiated into our elements1 is the
 equivalent of the first stage of       
progress towards the heschhat hyl1 or   
finished matter1 of the ancient         
philosophy4  ,if the material units of  
the existing order of nature are        
specialised portions of a relatively    
homogeneous materia prima--which were   
originated under conditions that have   
long ceased to exist and which remain   
unchanged and unchangeable under all    
conditions1 whether natural or          
artificial1 hitherto known to us--it    
follows that the speculation that they  
may be indefinitely altered1 or that new
 units may be generated under conditions
 yet to be discovered1 is perfectly     
legitimate4 ,theoretically1 at any rate1
 the transmutability of the elements is 
a verifiable scientific hypothesis2 and 
such inquiries as those which have been 
set afoot1 into the possible            
dissociative action of the great heat of

 the sun upon our elements1 are not only
 legitimate1 but are likely to yield    
results which1 whether affirmative or   
negative1 will be of great importance4  
,the idea that atoms are absolutely     
ingenerable and immutable 'manufactured 
articles' stands on the same sort of    
foundation as the idea that biological  
species are 'manufactured articles'     
stood thirty years ago2 and the supposed
 constancy of the elementary atoms1     
during the enormous lapse of time       
measured by the existence of our        
universe1 is of no more weight against  
the possibility of change in them1 in   
the infinity of antecedent time1 than   
the constancy of species in ,egypt1     
since the days of ,rameses or ,cheops1  
is evidence of their immutability during
 all past epochs of the earth's history4
 ,it seems safe to prophesy that the    
hypothesis of the evolution of the      
elements from a primitive matter will1  
in future1 play no less a part in the   
history of science than the atomic      

hypothesis1 which1 to begin with1 had no
 greater1 if so great1 an empirical     
foundation4  ,sidenote3 ,the old and the
 new atomic theory4  ,it may perhaps    
occur to the reader that the boasted    
progress of physical science does not   
come to much1 if our present conceptions
 of the fundamental nature of matter are
 expressible in terms employed1 more    
than two thousand years ago1 by the old 
'master of those that know4' ,such a    
criticism1 however1 would involve       
forgetfulness of the fact1 that the     
connotation of these terms1 in the mind 
of the modern1 is almost infinitely     
different from that which they possessed
 in the mind of the ancient1            
philosopher4 ,in antiquity1 they meant  
little more than vague speculation2 at  
the present day1 they indicate definite 
physical conceptions1 susceptible of    
mathematical treatment1 and giving rise 
to innumerable deductions1 the value of 
which can be experimentally tested4 ,the
 old notions produced little more than  

floods of dialectics2 the new are       
powerful aids towards the increase of   
solid knowledge4  ,sidenote3 7#b7       
,conservation of energy4  ,everyday     
observation shows that1 of the bodies   
which compose the material world1 some  
are in motion and some are1 or appear to
 be1 at rest4 ,of the bodies in motion1 
some1 like the sun and stars1 exhibit a 
constant movement1 regular in amount and
 direction1 for which no external cause 
appears4 ,others1 as stones and smoke1  
seem also to move of themselves when    
external impediments are taken away4    
,but these appear to tend to move in    
opposite directions3 the bodies we call 
heavy1 such as stones1 downwards1 and   
the bodies we call light1 at least such 
as smoke and steam1 upwards4 ,and1 as we
 further notice that the earth1 below   
our feet1 is made up of heavy matter1   
while the air1 above our heads1 is      
extremely light matter1 it is easy to   
regard this fact as evidence that the   
lower region is the place to which heavy

 things tend--their proper place1 in    
short--while the upper region is the    
proper place of light things2 and to    
generalise the facts observed by saying 
that bodies1 which are free to move1    
tend towards their proper places4 ,all  
these seem to be natural motions1       
dependent on the inherent faculties1 or 
tendencies1 of bodies themselves4 ,but  
there are other motions which are       
artificial or violent1 as when a stone  
is thrown from the hand1 or is knocked  
by another stone in motion4 ,in such    
cases as these1 for example1 when a     
stone is cast from the hand1 the        
distance travelled by the stone appears 
to depend partly on its weight and      
partly upon the exertion of the thrower4
 ,so that1 the weight of the stone      
remaining the same1 it looks as if the  
motive power communicated to it were    
measured by the distance to which the   
stone travels--as if1 in other words1   
the power needed to send it a hundred   
yards was twice as great as that needed 

to send it fifty yards4 ,these1         
apparently obvious1 conclusions from the
 everyday appearances of rest and motion
 fairly represent the state of opinion  
upon the subject which prevailed among  
the ancient ,greeks1 and remained       
dominant until the age of ,galileo4 ,the
 publication of the ',principia' of     
,newton1 in #afhf-g1 marks the epoch at 
which the progress of mechanical physics
 had effected a complete revolution of  
thought on these subjects4 ,by this     
time1 it had been made clear that the   
old generalisations were either         
incomplete or totally erroneous2 that a 
body1 once set in motion1 will continue 
to move in a straight line for any      
conceivable time or distance1 unless it 
is interfered with2 that any change of  
motion is proportional to the 'force'   
which causes it1 and takes place in the 
direction in which that 'force' is      
exerted2 and that1 when a body in motion
 acts as a cause of motion on another1  
the latter gains as much as the former  

loses1 and vice vers4 ,it is to be      
noted1 however1 that while1 in          
contradistinction to the ancient idea of
 the inherent tendency to motion of     
bodies1 the absence of any such         
spontaneous power of motion was accepted
 as a physical axiom by the moderns1 the
 old conception virtually maintained    
itself is a new shape4 ,for1 in spite of
 ,newton's well-known warning against   
the 'absurdity' of supposing that one   
body can act on another at a distance   
through a vacuum1 the ultimate particles
 of matter were generally assumed to be 
the seats of perennial causes of motion 
termed 'attractive and repulsive        
forces1' in virtue of which1 any two    
such particles1 without any external    
impression of motion1 or intermediate   
material agent1 were supposed to tend to
 approach or remove from one another2   
and this view of the duality of the     
causes of motion is very widely held at 
the present day4  ,another important    
result of investigation1 attained in the

 seventeenth century1 was the proof and 
quantitative estimation of physical     
inertia4 ,in the old philosophy1 a      
curious conjunction of ethical and      
physical prejudices had led to the      
notion that there was something         
ethically bad and physically obstructive
 about matter4 ,aristotle attributes all
 irregularities and apparent            
dysteleologies in nature to the         
disobedience1 or sluggish yielding1 of  
matter to the shaping and guiding       
influence of those reasons and causes   
which were hypostatised in his ideal    
',forms4' ,in modern science1 the       
conception of the inertia1 or resistance
 to change1 of matter is complex4 ,in   
part1 it contains a corollary from the  
law of causation3 ,a body cannot change 
its state in respect of rest or motion  
without a sufficient cause4 ,but1 in    
part1 it contains generalisations from  
experience4 ,one of these is that there 
is no such sufficient cause resident in 
any body1 and that therefore it will    

rest1 or continue in motion1 so long as 
no external cause of change acts upon   
it4 ,the other is that the effect which 
the impact of a body in motion produces 
upon the body on which it impinges      
depends1 other things being alike1 on   
the relation of a certain quality of    
each which is called 'mass4' ,given a   
cause of motion of a certain value1 the 
amount of motion1 measured by distance  
travelled in a certain time1 which it   
will produce in a given quantity of     
matter1 say a cubic inch1 is not always 
the same1 but depends on what that      
matter is--a cubic inch of iron will go 
faster than a cubic inch of gold4       
,hence1 it appears1 that since equal    
amounts of motion have1 ex hypothesi1   
been produced1 the amount of motion in a
 body does not depend on its speed      
alone1 but on some property of the body4
 ,to this the name of 'mass' has been   
given4 ,and since it seems reasonable to
 suppose that a large quantity of       
matter1 moving slowly1 possesses as much

 motion as a small quantity moving      
faster1 'mass' has been held to express 
'quantity of matter4' ,it is further    
demonstrable that1 at any given time and
 place1 the relative mass of any two    
bodies is expressed by the ratio of     
their weights4  ,sidenote3 ,mechanical  
theory of heat4  ,when all these great  
truths respecting molar motion1 or the  
movements of visible and tangible       
masses1 had been shown to hold good not 
only of terrestrial bodies1 but of all  
those which constitute the visible      
universe1 and the movements of the      
macrocosm had thus been expressed by a  
general mechanical theory1 there        
remained a vast number of phenomena1    
such as those of light1 heat1           
electricity1 magnetism1 and those of the
 physical and chemical changes1 which do
 not involve molar motion4 ,newton's    
corpuscular theory of light was an      
attempt to deal with one great series of
 these phenomena on mechanical          
principles1 and it maintained its ground

 until1 at the beginning of the         
nineteenth century1 the undulatory      
theory proved itself to be a much better
 working hypothesis4 ,heat1 up to that  
time1 and indeed much later1 was        
regarded as an imponderable substance1  
caloric2 as a thing which was absorbed  
by bodies when they were wanned1 and was
 given out as they cooled2 and which1   
moreover1 was capable of entering into a
 sort of chemical combination with them1
 and so becoming latent4 ,rumford and   
,davy had given a great blow to this    
view of heat by proving that the        
quantity of heat which two portions of  
the same body could be made to give out1
 by rubbing them together1 was          
practically illimitable4 ,this result   
brought philosophers face to face with  
the contradiction of supposing that a   
finite body could contain an infinite   
quantity of another body2 but it was not
 until #ahdc1 that clear and            
unquestionable experimental proof was   
given of the fact that there is a       

definite relation between mechanical    
work and heat2 that so much work always 
gives rise1 under the same conditions1  
to so much heat1 and so much heat to so 
much mechanical work4 ,thus originated  
the mechanical theory of heat1 which    
became the starting-point of the modern 
doctrine of the conservation of energy4 
,molar motion had appeared to be        
destroyed by friction4 ,it was proved   
that no destruction took place1 but that
 an exact equivalent of the energy of   
the lost molar motion appears as that of
 the molecular motion1 or motion of the 
smallest particles of a body1 which     
constitutes heat4 ,the loss of the      
masses is the gain of their particles4  
,sidenote3 ,earlier approaches towards  
doctrine of conservation4  ,before      
#ahdc1 however1 the doctrine of         
conservation of energy had been         
approached ,bacon's chief contribution  
to positive science is the happy guess  
7for the context shows that it was      
little more7 that heat may be a mode of 

motion2 ,descartes affirmed the quantity
 of motion in the world to be constant2 
,newton nearly gave expression to the   
complete theorem2 while ,rumford's and  
,davy's experiments suggested1 though   
they did not prove1 the equivalency of  
mechanical and thermal energy4 ,again1  
the discovery of voltaic electricity1   
and the marvellous development of       
knowledge1 in that field1 effected by   
such men as ,davy1 ,faraday1 ,oersted1  
,ampre1 and ,melloni1 had brought to    
light a number of facts which tended to 
show that the so-called 'forces' at work
 in light1 heat1 electricity1 and       
magnetism1 in chemical and in mechanical
 operations1 were intimately1 and1 in   
various cases1 quantitatively related4  
,it was demonstrated that any one could 
be obtained at the expense of any other2
 and apparatus was devised which        
exhibited the evolution of all these    
kinds of action from one source of      
energy4 ,hence the idea of the          
'correlation of forces' which was the   

immediate forerunner of the doctrine of 
the conservation of energy4  ,it is a   
remarkable evidence of the greatness of 
the progress in this direction which has
 been effected in our time1 that even   
the second edition of the ',history of  
the ,inductive ,sciences1' which was    
published in #ahdf1 contains no allusion
 either to the general view of the      
',correlation of ,forces' published in  
,england in #ahdb1 or to the publication
 in #ahdc of the first of the series of 
experiments by which the mechanical     
equivalent of heat was correctly        
ascertained4,i ,such a failure on the   
part of a contemporary1 of great        
acquirements and remarkable intellectual
 powers1 to read the signs of the times1
 is a lesson and a warning worthy of    
being deeply pondered by anyone who     
attempts to prognosticate the course of 
scientific progress4  ,sidenote3 ,what  
this doctrine is4  ,i have pointed out  
that the growth of clear and definite   
views respecting the constitution of    

matter has led to the conclusion that1  
so far as natural agencies are          
concerned1 it is ingenerable and        
indestructible4 ,in so far as matter may
 be conceived to exist in a purely      
passive state1 it is1 imaginably1 older 
than motion4 ,but1 as it must be assumed
 to be susceptible of motion1 a particle
 of bare matter at rest must be endowed 
with the potentiality of motion4 ,such a
 particle1 however1 by the supposition1 
can have no energy1 for there is no     
cause why it should move4 ,suppose now  
that it receives an impulse1 it will    
begin to move with a velocity inversely 
proportional to its mass1 on the one    
hand1 and directly proportional to the  
strength of the impulse1 on the other1  
and will possess kinetic energy1 in     
virtue of which it will not only        
continue to move for ever if unimpeded1 
but if it impinges on another such      
particle1 it will impart more or less of
 its motion1 to the latter4 ,let it be  
conceived that the particle acquires a  

tendency to move1 and that nevertheless 
it does not move4 ,it is then in a      
condition totally different from that in
 which it was at first4 ,a cause        
competent to produce motion is operating
 upon it1 but1 for some reason or other1
 is unable to give rise to motion4 ,if  
the obstacle is removed1 the energy     
which was there1 but could not manifest 
itself1 at once gives rise to motion4   
,while the restraint lasts1 the energy  
of the particle is merely potential2 and
 the case supposed illustrates what is  
meant by potential energy4 ,in this     
contrast of the potential with the      
actual1 modern physics is turning to    
account the most familiar of            
,aristotelian distinctions--that between
 dunamis and energeia4  ,that kinetic   
energy appears to be imparted by impact 
is a fact of daily and hourly           
experience3 we see bodies set in motion 
by bodies1 already in motion1 which seem
 to come in contact with them4 ,it is a 
truth which could have been learned by  

nothing but experience1 and which cannot
 be explained1 but must be taken as an  
ultimate fact about which1 explicable or
 inexplicable1 there can be no doubt4   
,strictly speaking1 we have no direct   
apprehension of any other cause of      
motion4 ,but experience furnishes       
innumerable examples of the production  
of kinetic energy in a body previously  
at rest1 when no impact is discernible  
as the cause of that energy4 ,in all    
such cases1 the presence of a second    
body is a necessary condition2 and the  
amount of kinetic energy1 which its     
presence enables the first to gain1 is  
strictly dependent on the relative      
positions of the two4 ,hence the phrase 
energy of position1 which is frequently 
used as equivalent to potential energy4 
,if a stone is picked up and held1 say1 
six feet above the ground1 it has       
potential energy1 because1 if let go1 it
 will immediately begin to move towards 
the earth2 and this energy may be said  
to be energy of position1 because it    

depends upon the relative position of   
the earth and the stone4 ,the stone is  
solicited to move but cannot1 so long as
 the muscular strength of the holder    
prevents the solicitation from taking   
effect4 ,the stone1 therefore1 has      
potential energy1 which becomes kinetic 
if it is let go1 and the amount of that 
kinetic energy which will be developed  
before it strikes the earth depends on  
its position--on the fact that it is1   
say1 six feet off the earth1 neither    
more nor less4 ,moreover1 it can be     
proved that the raiser of the stone had 
to exert as much energy in order to     
place it in its position1 as it will    
develop in falling4 ,hence the energy   
which was exerted1 and apparently       
exhausted1 in raising the stone1 is     
potentially in the stone1 in its raised 
position1 and will manifest itself when 
the stone is set free4 ,thus the energy1
 withdrawn from the general stock to    
raise the stone1 is returned when it    
falls1 and there is no change in the    

total amount4 ,energy1 as a whole1 is   
conserved4  ,taking this as a very broad
 and general statement of the essential 
facts of the case1 the raising of the   
stone is intelligible enough1 as a case 
of the communication of motion from one 
body to another4 ,but the potential     
energy of the raised stone is not so    
easily intelligible4 ,to all appearance1
 there is nothing either pushing or     
pulling it towards the earth1 or the    
earth towards it2 and yet it is quite   
certain that the stone tends to move    
towards the earth and the earth towards 
the stone1 in the way defined by the law
 of gravitation4  ,in the currently     
accepted language of science1 the cause 
of motion1 in all such cases as this1   
when bodies tend to move towards or away
 from one or another1 without any       
discernible impact of other bodies1 is  
termed a 'force1' which is called       
'attractive' in the one case1 and       
'repulsive' in the other4 ,and such     
attractive or repulsive forces are often

 spoken of as if they were real things1 
capable of exerting a pull1 or a push1  
upon the particles of matter concerned4 
,thus the potential energy of the stone 
is commonly said to be due to the       
'force' of gravity which is continually 
operating upon it4  ,another            
illustration may make the case plainer4 
,the bob of a pendulum swings first to  
one side and then to the other of the   
centre of the arc which it describes4   
,suppose it to have just reached the    
summit of its right-hand half-swing4 ,it
 is said that the 'attractive forces' of
 the bob for the earth1 and of the earth
 for the bob1 set the former in motion2 
and as these 'forces' are continually in
 operation1 they confer an accelerated  
velocity on the bob2 until1 when it     
reaches the centre of its swing1 it is1 
so to speak1 fully charged with kinetic 
energy4 ,if1 at this moment1 the whole  
material universe1 except the bob1 were 
abolished1 it would move for ever in the
 direction of a tangent to the middle of

 the arc described4 ,as a matter of     
fact1 it is compelled to travel through 
its left-hand half-swing1 and thus      
virtually to go up hill4 ,consequently1 
the 'attractive forces' of the bob and  
the earth are now acting against it1 and
 constitute a resistance which the      
charge of kinetic energy has to         
overcome4 ,but1 as this charge          
represents the operation of the         
attractive forces during the passage of 
the bob through the right-hand          
half-swing down to the centre of the    
arc1 so it must needs be used up by the 
passage of the bob upwards from the     
centre of the arc to the summit of the  
left-hand half-swing4 ,hence1 at this   
point1 the bob comes to a momentary     
rest4 ,the last fraction of kinetic     
energy is just neutralised by the action
 of the attractive forces1 and the bob  
has only potential energy equal to that 
with which it started4 ,so that the sum 
of the phenomena may be stated thus3 ,at
 the summit of either half-arc of its   

swing1 the bob has a certain amount of  
potential energy2 as it descends it     
gradually exchanges this for kinetic    
energy1 until at the centre it possesses
 an equivalent amount of kinetic energy2
 from this point onwards1 it gradually  
loses kinetic energy as it ascends1     
until1 at the summit of the other       
half-arc1 it has acquired an exactly    
similar amount of potential energy4     
,thus1 on the whole transaction1 nothing
 is either lost or gained2 the quantity 
of energy is always the same1 but it    
passes from one form into the other4    
,to all appearance1 the phenomena       
exhibited by the pendulum are not to be 
accounted for by impact3 in fact1 it is 
usually assumed that corresponding      
phenomena would take place if the earth 
and the pendulum were situated in an    
absolute vacuum1 and at any conceivable 
distance from1 one another4 ,if this be 
so1 it follows that there must be two   
totally different kinds of causes of    
motion3 the one impact--a vera causa1 of

 which1 to all appearance1 we have      
constant experience2 the other1         
attractive or repulsive 'force'--a      
metaphysical entity which is physically 
inconceivable4 ,newton expressly        
repudiated the notion of the existence  
of attractive forces1 in the sense in   
which that term is ordinarily           
understood2 and he refused to put       
forward any hypothesis as to the        
physical cause of the so-called         
'attraction of gravitation4' ,as a      
general rule1 his successors have been  
content to accept the doctrine of       
attractive and repulsive forces1 without
 troubling themselves about the         
philosophical difficulties which it     
involves4 ,but this has not always been 
the case2 and the attempt of ,le ,sage1 
in the last century1 to show that the   
phenomena of attraction and repulsion   
are susceptible of explanation by his   
hypothesis of bombardment by            
ultra-mundane particles1 whether tenable
 or not1 has the great merit of being an

 attempt to get rid of the dual         
conception of the causes of motion which
 has hitherto prevailed4 ,on this       
hypothesis1 the hammering of the        
ultra-mundane corpuscles on the bob     
confers its kinetic energy1 on the one  
hand1 and takes it away on the other2   
and the state of potential energy means 
the condition of the bob during the     
instant at which the energy1 conferred  
by the hammering during the one         
half-arc1 has just been exhausted by the
 hammering during the other half-arc4   
,it seems safe to look forward to the   
time when the conception of attractive  
and repulsive forces1 having served its 
purpose as a useful piece of scientific 
scaffolding1 will be replaced by the    
deduction of the phenomena known as     
attraction and repulsion1 from the      
general laws of motion4  ,the doctrine  
of the conservation of energy which ,i  
have endeavored to illustrate is thus   
defined by the late ,clerk ,maxwell3    
',the total energy of any body or system

 of bodies is a quantity which can      
neither be increased nor diminished by  
any mutual action of such bodies1 though
 it may be transformed into any one of  
the forms of which energy is            
susceptible4' ,it follows that energy1  
like matter1 is indestructible and      
ingenerable in nature4 ,the phenomenal  
world1 so far as it is material1        
expresses the evolution and involution  
of energy1 its passage from the kinetic 
to the potential condition and back     
again4 ,wherever motion of matter takes 
place1 that motion is effected at the   
expense of part of the total store of   
energy4  ,hence1 as the phenomena       
exhibited by living beings1 in so far as
 they are material1 are all molar or    
molecular motions1 these are included   
under the general law4 ,a living body is
 a machine by which energy is           
transformed in the same sense as a      
steam-engine is so1 and all its         
movements1 molar and molecular1 are to  
be accounted for by the energy which is 

supplied to it4 ,the phenomena of       
consciousness which arise1 along with   
certain transformations of energy1      
cannot be interpolated in the series of 
these transformations1 inasmuch as they 
are not motions to which the doctrine of
 the conservation of energy applies4    
,and1 for the same reason1 they do not  
necessitate the using up of energy2 a   
sensation has no mass and cannot be     
conceived to be susceptible of movement4
 ,that a particular molecular motion    
does give rise to a state of            
consciousness is experimentally certain2
 but the how and why of the process are 
just as inexplicable as in the case of  
the communication of kinetic energy by  
impact4  ,when dealing with the doctrine
 of the ultimate constitution of matter1
 we found a certain resemblance between 
the oldest speculations and the newest  
doctrines of physical philosophers4 ,but
 there is no such resemblance between   
the ancient and modern views of motion  
and its causes1 except in so far as the 

conception of attractive and repulsive  
forces may be regarded as the modified  
descendant of the ,aristotelian         
conception of forms4 ,in fact1 it is    
hardly too much to say that the         
essential and fundamental difference    
between ancient and modern physical     
science lies in the ascertainment of the
 true laws of statics and dynamics in   
the course of the last three centuries2 
and in the invention of mathematical    
methods of dealing with all the         
consequences of these laws4 ,the        
ultimate aim of modern physical science 
is the deduction of the phenomena       
exhibited by material bodies from       
physico-mathematical first principles4  
,whether the human intellect is strong  
enough to attain the goal set before it 
may be a question1 but thither will it  
surely strive4  ,sidenote3 7#c7         
,evolution4  ,the third great scientific
 event of our time1 the rehabilitation  
of the doctrine of evolution1 is part of
 the same tendency of increasing        

knowledge to unify itself1 which has led
 to the doctrine of the conservation of 
energy4 ,and this tendency1 again1 is   
mainly a product of the increasing      
strength conferred by physical          
investigation on the belief in the      
universal validity of that orderly      
relation of facts1 which we express by  
the so-called ',laws of ,nature4'       
,sidenote3 ,early stages of this theory 
,the growth of a plant from its seed1 of
 an animal from its egg1 the apparent   
origin of innumerable living things from
 mud1 or from the putrefying remains of 
former organisms1 had furnished the     
earlier scientific thinkers with        
abundant analogies suggestive of the    
conception of a corresponding method of 
cosmic evolution from a formless 'chaos'
 to an ordered world which might either 
continue for ever or undergo dissolution
 into its elements before starting on a 
new course of evolution4 ,it is         
therefore no wonder that1 from the days 
of the ,ionian school onwards1 the view 

that the universe was the result of such
 a process should have maintained itself
 as a leading dogma of philosophy4 ,the 
emanistic theories which played so great
 a part in ,neoplatonic philosophy and  
,gnostic theology are forms of          
evolution4 ,in the seventeenth century1 
,descartes propounded a scheme of       
evolution1 as an hypothesis of what     
might have been the mode of origin of   
the world1 while professing to accept   
the ecclesiastical scheme of creation1  
as an account of that which actually was
 its manner of coming into existence4   
,in the eighteenth century1 ,kant put   
forth a remarkable speculation as to the
 origin of the solar system1 closely    
similar to that subsequently adopted by 
,laplace and destined to become famous  
under the title of the 'nebular         
hypothesis4'  ,the careful observations 
and the acute reasonings of the ,italian
 geologists of the seventeenth and      
eighteenth centuries2 the speculations  
of ,leibnitz in the ',protogaea' and of 

,buffon in his ',thorie de la ,terre2'  
the sober and profound reasonings of    
,hutton1 in the latter part of the      
eighteenth century2 all these tended to 
show that the fabric of the earth itself
 implied the continuance of processes of
 natural causation for a period of time 
as great1 in relation to human history1 
as the distances of the heavenly bodies 
from us are1 in relation to terrestrial 
standards of measurement4 ,the abyss of 
time began to loom as large as the abyss
 of space4 ,and this revelation to sight
 and touch1 of a link here and a link   
there of a practically infinite chain of
 natural causes and effects1 prepared   
the way1 as perhaps nothing else has    
done1 for the modern form of the ancient
 theory of evolution4  ,in the beginning
 of the eighteenth century1 ,de ,maillet
 made the first serious attempt to apply
 the doctrine to the living world4 ,in  
the latter part of it1 ,erasmus ,darwin1
 ,goethe1 ,treviranus1 and ,lamarck took
 up the work more vigorously and with   

better qualifications4 ,the question of 
special creation1 or evolution1 lay at  
the bottom of the fierce disputes which 
broke out in the ,french ,academy       
between ,cuvier and ,st4-,hilaire2 and1 
for a time1 the supporters of biological
 evolution were silenced1 if not        
answered1 by the alliance of the        
greatest naturalist of the age with     
their ecclesiastical opponents4         
,catastrophism1 a short-sighted         
teleology1 and a still more             
short-sighted orthodoxy1 joined forces  
to crush evolution4  ,lyell and ,poulett
 ,scrope1 in this country1 resumed the  
work of the ,italians and of ,hutton2   
and the former1 aided by a marvellous   
power of clear exposition1 placed upon  
an irrefragable basis the truth that    
natural causes are competent to account 
for all events1 which can be proved to  
have occurred1 in the course of the     
secular changes which have taken place  
during the deposition of the stratified 
rocks4 ,the publication of ',the        

,principles of ,geology1' in #ahcj1     
constituted an epoch in geological      
science4 ,but it also constituted an    
epoch in the modern history of the      
doctrines of evolution1 by raising in   
the mind of every intelligent reader    
this question3 ,if natural causation is 
competent to account for the not-living 
part of our globe1 why should it not    
account for the living part8  ,by       
keeping this question before the public 
for some thirty years1 ,lyell1 though   
the keenest and most formidable of the  
opponents of the transmutation theory1  
as it was formulated by ,lamarck1 was of
 the greatest possible service in       
facilitating the reception of the       
sounder doctrines of a later day4 ,and1 
in like fashion1 another vehement       
opponent of the transmutation of        
species1 the elder ,agassiz1 was doomed 
to help the cause he hated4 ,agassiz not
 only maintained the fact of the        
progressive advance in organisation of  
the inhabitants of the earth at each    

successive geological epoch1 but he     
insisted upon the analogy of the steps  
of this progression with those by which 
the embryo advances to the adult        
condition1 among the highest forms of   
each group4 ,in fact1 in endeavoring to 
support these views he went a good way  
beyond the limits of any cautious       
interpretation of the facts then known4 
,sidenote3 ,darwin  ,although little    
acquainted with biological science1     
,whewell seems to have taken particular 
pains with that part of his work which  
deals with the history of geological and
 biological speculation2 and several    
chapters of his seventeenth and         
eighteenth books1 which comprise the    
history of physiology1 of comparative   
anatomy and of the paltiological        
sciences1 vividly reproduce the         
controversies of the early days of the  
,victorian epoch4 ,but here1 as in the  
case of the doctrine of the conservation
 of energy1 the historian of the        
inductive sciences has no prophetic     

insight2 not even a suspicion of that   
which the near future was to bring      
forth4 ,and those who still repeat the  
once favorite objection that ,darwin's  
',origin of ,species' is nothing but a  
new version of the ',philosophie        
zoologique' will find that1 so late as  
#ahdd1 ,whewell had not the slightest   
suspicion of ,darwin's main theorem1    
even as a logical possibility4 ,in fact1
 the publication of that theorem by     
,darwin and ,wallace1 in #ahei1 took all
 the biological world by surprise4      
,neither those who were inclined towards
 the 'progressive transmutation' or     
'development' doctrine1 as it was then  
called1 nor those who were opposed to   
it1 had the slightest suspicion that the
 tendency to variation in living beings1
 which all admitted as a matter of fact2
 the selective influence of conditions1 
which no one could deny to be a matter  
of fact1 when his attention was drawn to
 the evidence2 and the occurrence of    
great geological changes which also was 

matter of fact2 could be used as the    
only necessary postulates of a theory of
 the evolution of plants and animals    
which1 even if not at once1 competent to
 explain all the known facts of         
biological science1 could not be shown  
to be inconsistent with any4 ,so far as 
biology is concerned1 the publication of
 the ',origin of ,species1' for the     
first time1 put the doctrine of         
evolution1 in its application to living 
things1 upon a sound scientific         
foundation4 ,it became an instrument of 
investigation1 and in no hands did it   
prove more brilliantly profitable than  
in those of ,darwin himself4 ,his       
publications on the effects of          
domestication in plants and animals1 on 
the influence of cross-fertilisation1 on
 flowers as organs for effecting such   
fertilisation1 on insectivorous plants1 
on the motions of plants1 pointed out   
the routes of exploration which have    
since been followed by hosts of         
inquirers1 to the great profit of       

science4  ,darwin found the biological  
world a more than sufficient field for  
even his great powers1 and left the     
cosmical part of the doctrine to others4
 ,not much has been added to the nebular
 hypothesis1 since the time of ,laplace1
 except that the attempt to show        
7against that hypothesis7 that all nebul
 are star clusters1 has been met by the 
spectroscopic proof of the gaseous      
condition of some of them4 ,moreover1   
physicists of the present generation    
appear now to accept the secular cooling
 of the earth1 which is one of the      
corollaries of that hypothesis4 ,in     
fact1 attempts have been made1 by the   
help of deductions from the data of     
physics1 to lay down an approximate     
limit to the number of millions of years
 which have elapsed since the earth was 
habitable by living beings4 ,if the     
conclusions thus reached should stand   
the test of further investigation1 they 
will undoubtedly be very valuable4 ,but1
 whether true or false1 they can have no

 influence upon the doctrine of         
evolution in its application to living  
organisms4 ,the occurrence of successive
 forms of life upon our globe is an     
historical fact1 which cannot be        
disputed2 and the relation of these     
successive forms1 as stages of evolution
 of the same type1 is established in    
various cases4 ,the biologist has no    
means of determining the time over which
 the process of evolution has extended1 
but accepts the computation of the      
physical geologist and the physicist1   
whatever that may be4  ,sidenote3 and   
philosophy  ,evolution as a             
philosophical doctrine applicable to all
 phenomena1 whether physical or mental1 
whether manifested by material atoms or 
by men in society1 has been dealt with  
systematically in the ',synthetic       
,philosophy' of ,mr4 ,herbert ,spencer4 
,comment on that great undertaking would
 not be in place here4 ,i mention it    
because1 so far as ,i know1 it is the   
first attempt to deal1 on scientific    

principles1 with modern scientific facts
 and speculations4 ,for the             
',philosophic positive' of ,m4 ,comte1  
with which ,mr4 ,spencer's system of    
philosophy is sometimes compared1 though
 it professes a similar object1 is      
unfortunately permeated by a thoroughly 
unscientific spirit1 and its author had 
no adequate acquaintance with the       
physical sciences even of his own time4 
99       99       99       99       99  
,the doctrine of evolution1 so far as   
the present physical cosmos is          
concerned1 postulates the fixity of the 
rules of operation of the causes of     
motion in the material universe4 ,if all
 kinds of matter are modifications of   
one kind1 and if all modes of motion are
 derived from the same energy1 the      
orderly evolution of physical nature out
 of one substratum and one energy       
implies that the rules of action of that
 energy should be fixed and definite4   
,in the past history of the universe1   
back to that point1 there can be no room

 for chance or disorder4 ,but it is     
possible to raise the question whether  
this universe of simplest matter and    
definitely operating energy1 which forms
 our hypothetical starting point1 may   
not itself be a product of evolution    
from a universe of such matter1 in which
 the manifestations of energy were not  
definite--in which1 for example1 our    
laws of motion held good for some units 
and not for others1 or for the same     
units at one time and not at            
another--and which would therefore be a 
real epicurean chance-world8  ,for      
myself1 ,i must confess that ,i find the
 air of this region of speculation too  
rarefied for my constitution1 and ,i am 
disposed to take refuge in 'ignoramus et
 ignorabimus4'  ,sidenote3 ,other       
achievements in physical science4  ,the 
execution of my further task1 the       
indication of the most important        
achievements in the several branches of 
physical science during the last fifty  
years1 is embarrassed by the abundance  

of the objects of choice2 and by the    
difficulty which everyone1 but a        
specialist in each department1 must find
 in drawing a due distinction between   
discoveries which strike the imagination
 by their novelty1 or by their practical
 influence1 and those unobtrusive but   
pregnant observations and experiments in
 which the germs of the great things of 
the future really lie4 ,moreover1 my    
limits restrict me to little more than a
 bare chronicle of the events which ,i  
have to notice4  ,sidenote3 ,physics and
 chemistry4  ,in physics and chemistry1 
the old boundaries of which sciences are
 rapidly becoming effaced1 one can      
hardly go wrong in ascribing a primary  
value to the investigations into the    
relation between the solid1 liquid1 and 
gaseous states of matter on the one     
hand1 and degrees of pressure and of    
heat on the other4 ,almost all1 even the
 most refractory1 solids have been      
vaporised by the intense heat of the    
electric arc2 and the most refractory   

gases have been forced to assume the    
liquid1 and even the solid1 forms by the
 combination of high pressure with      
intense cold4 ,it has further been shown
 that there is no discontinuity between 
these states--that a gas passes into the
 liquid state through a condition which 
is neither one nor the other1 and that a
 liquid body becomes solid1 or a solid  
liquid1 by the intermediation of a      
condition in which it is neither truly  
solid nor truly liquid4  ,theoretical   
and experimental investigations have    
concurred in the establishment of the   
view that a gas is a body1 the particles
 of which are in incessant rectilinear  
motion at high velocities1 colliding    
with one another and bounding back when 
they strike the walls of the containing 
vessel2 and1 on this theory1 the already
 ascertained relations of gaseous bodies
 to heat and pressure have been shown to
 be deducible from mechanical           
principles4 ,immense improvements have  
been effected1 in the means of          

exhausting a given space of its gaseous 
contents2 and experimentation on the    
phenomena which attend the electric     
discharge and the action of radiant     
heat1 within the extremely rarefied     
media thus produced1 has yielded a great
 number of remarkable results1 some of  
which have been made familiar to the    
public by the ,gieseler tubes and the   
radiometer4 ,already1 these             
investigations have afforded an         
unexpected insight into the constitution
 of matter and its relations with       
thermal and electric energy1 and they   
open up a vast field for future inquiry 
into some of the deepest problems of    
physics4 ,other important steps1 in the 
same direction1 have been effected by   
investigations into the absorption of   
radiant heat proceeding from different  
sources by solid1 fluid1 and gaseous    
bodies4 ,and it is a curious example of 
the interconnection of the various      
branches of physical science1 that some 
of the results thus obtained have proved

 of great importance in meteorology4    
,sidenote3 ,the spectroscope4  ,the     
existence of numerous dark lines1       
constant in their number and position in
 the various regions of the solar       
spectrum1 was made out by ,fraunhofer in
 the early part of the present century1 
but more than forty years elapsed before
 their causes were ascertained and their
 importance recognised4 ,spectroscopy1  
which then took its rise1 is probably   
that employment of physical knowledge1  
already won1 as a means of further      
acquisition1 which most impresses the   
imagination4 ,for it has suddenly and   
immensely enlarged our power of         
overcoming the obstacles which almost   
infinite minuteness on the one hand1 and
 almost infinite distance on the other1 
have hitherto opposed to the recognition
 of the presence and the condition of   
matter4 ,one eighteen-millionth of a    
grain of sodium in the flame of a       
spirit-lamp may be detected by this     
instrument2 and1 at the same time1 it   

gives trust-worthy indications of the   
material constitution not only of the   
sun1 but of the farthest of those fixed 
stars and nebul which afford sufficient 
light to affect the eye1 or the         
photographic plate1 of the inquirer4    
,sidenote3 ,electricity4  ,the          
mathematical and experimental           
elucidation of the phenomena of         
electricity1 and the study of the       
relations of this form of energy with   
chemical and thermal action1 had made   
extensive progress before #ahcg4 ,but   
the determination of the influence of   
magnetism on light1 the discovery of    
diamagnetism1 of the influence of       
crystalline structure on magnetism1 and 
the completion of the mathematical      
theory of electricity1 all belong to the
 present epoch4 ,to it also appertain   
the practical execution and the working 
out of the results of the great         
international system of observations on 
terrestrial magnetism1 suggested by     
,humboldt in #ahcf2 and the invention of

 instruments of infinite delicacy and   
precision for the quantitative          
determination of electrical phenomena4  
,the voltaic battery has received vast  
improvements2 while the invention of    
magneto-electric engines and of improved
 means of producing ordinary electricity
 has provided sources of electrical     
energy vastly superior to any before    
extant in power1 and far more convenient
 for use4  ,it is perhaps this branch of
 physical science which may claim the   
palm for its practical fruits1 no less  
than for the aid which it has furnished 
to the investigation of other parts of  
the field of physical science4 ,the idea
 of the practicability of establishing a
 communication between distant points1  
by means of electricity1 could hardly   
fail to have simmered in the minds of   
ingenious men since1 well nigh a century
 ago1 experimental proof was given that 
electric disturbances could be          
propagated through a wire twelve        
thousand feet long4 ,various methods of 

carrying the suggestion into practice   
had been carried out with some degree of
 success2 but the system of electric    
telegraphy1 which1 at the present time1 
brings all parts of the civilised world 
within a few minutes of one another1    
originated only about the commencement  
of the epoch under consideration4 ,in   
its influence on the course of human    
affairs1 this invention takes its place 
beside that of gunpowder1 which tended  
to abolish the physical inequalities of 
fighting men2 of printing1 which tended 
to destroy the effect of inequalities in
 wealth among learning men2 of steam    
transport1 which has done the like for  
travelling men4 ,all these gifts of     
science are aids in the process of      
levelling up2 of removing the ignorant  
and baneful prejudices of nation against
 nation1 province against province1 and 
class against class2 of assuring that   
social order which is the foundation of 
progress1 which has redeemed ,europe    
from barbarism1 and against which one is

 glad to think that those who1 in our   
time1 are employing themselves in       
fanning the embers of ancient wrong1 in 
setting class against class1 and in     
trying to tear asunder the existing     
bonds of unity1 are undertaking a futile
 struggle4 ,the telephone is only second
 in practical importance to the electric
 telegraph4 ,invented1 as it were1 only 
the other day1 it has already taken its 
place as an appliance of daily life4    
,sixty years ago1 the extraction of     
metals from their solutions1 by the     
electric current1 was simply a highly   
interesting scientific fact4 ,at the    
present day1 the galvano-plastic art is 
a great industry2 and1 in combination   
with photography1 promises to be of     
endless service in the arts4 ,electric  
lighting is another great gift of       
science to civilisation1 the practical  
effects of which have not yet been fully
 developed1 largely on account of its   
cost4 ,but those whose memories go back 
to the tinder-box period1 and recollect 

the cost of the first lucifer matches1  
will not despair of the results of the  
application of science and ingenuity to 
the cheap production of anything for    
which there is a large demand4  ,the    
influence of the progress of electrical 
knowledge and invention upon that of    
investigation in other fields of science
 is highly remarkable4 ,the combination 
of electrical with mechanical           
contrivances has produced instruments by
 which1 not only may extremely small    
intervals of time be exactly measured1  
but the varying rapidity of movements1  
which take place in such intervals and  
appear to the ordinary sense            
instantaneous1 is recorded4 ,the        
duration of the winking of an eye is a  
proverbial expression for an            
instantaneous action2 but1 by the help  
of the revolving cylinder and the       
electrical marking-apparatus1 it is     
possible to obtain a graphic record of  
such an action1 in which1 if it endures 
a second1 that second shall be          

subdivided into a hundred1 or a         
thousand1 equal parts1 and the state of 
the action at each hundredth1 or        
thousandth1 of a second exhibited4 ,in  
fact1 these instruments may be said to  
be time-microscopes4 ,such appliances   
have not only effected a revolution in  
physiology1 by the power of analysing   
the phenomena of muscular and nervous   
activity which they have conferred1 but 
they have furnished new methods of      
measuring the rate of movement of       
projectiles to the artillerist4 ,again1 
the microphone1 which renders the       
minutest movements audible1 and which   
enables a listener to hear the footfall 
of a fly1 has equipped the sense of     
hearing with the means of entering      
almost as deeply into the penetralia of 
nature1 as does the sense of sight4     
,sidenote3 ,photography as an instrument
 of science4  ,that light exerts a      
remarkable influence in bringing about  
certain chemical combinations and       
decompositions was well known fifty     

years ago1 and various more or less     
successful attempts to produce permanent
 pictures1 by the help of that          
knowledge1 had already been made4 ,it   
was not till #ahci1 however1 that       
practical success was obtained2 but the 
'daguerreotypes' were both cumbrous and 
costly1 and photography would never have
 attained its present important         
development had not the progress of     
invention substituted paper and glass   
for the silvered plates then in use4 ,it
 is not my affair to dwell upon the     
practical application of the photography
 of the present day1 but it is germane  
to my purpose to remark that it has     
furnished a most valuable accessory to  
the methods of recording motions and    
lapse of time already in existence4 ,in 
the hands of the astronomer and the     
meteorologist1 it has yielded means of  
registering terrestrial1 solar1         
planetary1 and stellar phenomena1       
independent of the sources of error     
attendant on ordinary observation2 in   

the hands of the physicist1 not only    
does it record spectroscopic phenomena  
with unsurpassable ease and precision1  
but it has revealed the existence of    
rays having powerful chemical energy1 or
 beyond the visible limits of either end
 of the spectrum2 while1 to the         
naturalist1 it furnishes the means by   
which the forms of many highly          
complicated objects may be represented1 
without that possibility of error which 
is inherent in the work of the          
draughtsman4 ,in fact1 in many cases1   
the stern impartiality of photography is
 an objection to its employment3 it     
makes no distinction between the        
important and the unimportant2 and hence
 photographs of dissections1 for        
example1 are rarely so useful as the    
work of a draughtsman who is at once    
accurate and intelligent4  ,sidenote3   
,astronomy1  ,the determination of the  
existence of a new planet1 ,neptune1 far
 beyond the previously known bounds of  
the solar system1 by mathematical       

deduction from the facts of             
perturbation2 and the immediate         
confirmation of that determination1 in  
the year #ahdf1 by observers who turned 
their telescopes into the part of the   
heavens indicated as its place1         
constitute a remarkable testimony of    
nature to the validity of the principles
 of the astronomy of our time4 ,in      
addition1 so many new asteroids have    
been added to those which were already  
known to circulate in the place which   
theoretically should be occupied by a   
planet1 between ,mars and ,jupiter1 that
 their number now amounts to between two
 and three hundred4 ,i have already     
alluded to the extension of our         
knowledge of the nature of the heavenly 
bodies by the employment of             
spectroscopy4 ,it has not only thrown   
wonderful light upon the physical and   
chemical constitution of the sun1 fixed 
stars1 and nebul1 and comets1 but it    
holds out a prospect of obtaining       
definite evidence as to the nature of   

our so-called elementary bodies4        
,sidenote3 its relation to geology4     
,the application of the generalisations 
of thermotics to the problem of the     
duration of the earth1 and of deductions
 from tidal phenomena to the            
determination of the length of the day  
and of the time of revolution of the    
moon1 in past epochs of the history of  
the universe2 and the demonstration of  
the competency of the great secular     
changes1 known under the general name of
 the precession of the equinoxes1 to    
cause corresponding modifications in the
 climate of the two hemispheres of our  
globe1 have brought astronomy into      
intimate relation with geology4         
,geology1 in fact1 proves that1 in the  
course of the past history of the earth1
 the climatic conditions of the same    
region have been widely different1 and  
seeks the explanation of this important 
truth from the sister sciences4 ,the    
facts that1 in the middle of the        
,tertiary epoch1 evergreen trees        

abounded within the arctic circle2 and  
that1 in the long subsequent ,quaternary
 epoch1 an arctic climate1 with its     
accompaniment of gigantic glaciers1     
obtained in the northern hemisphere1 as 
far south as ,switzerland and ,central  
,france1 are as well established as any 
truths of science4 ,but1 whether the    
explanation of these extreme variations 
in the mean temperature of a great part 
of the northern hemisphere is to be     
sought in the concomitant changes in the
 distribution of land and water surfaces
 of which geology affords evidence1 or  
in astronomical conditions1 such as     
those to which ,i have referred1 is a   
question which must await its answer    
from the science of the future4         
,sidenote3 ,biological sciences4        
,sidenote3 ,the 'cell theory4'  ,turning
 now to the great steps in that progress
 which the biological sciences have made
 since #ahcg1 we are met1 on the        
threshold of our epoch1 with perhaps the
 greatest of all--namely1 the           

promulgation by ,schwann1 in #ahci1 of  
the generalisation known as the 'cell   
theory1' the application and extension  
of which by a host of subsequent        
investigators has revolutionised        
morphology1 development1 and physiology4
 ,thanks to the immense series of labors
 thus inaugurated1 the following        
fundamental truths have been            
established4  ,sidenote3 ,fundamental   
truths established4  ,all living bodies 
contain substances of closely similar   
physical and chemical composition1 which
 constitute the physical basis of life1 
known as protoplasm4 ,so far as our     
present knowledge goes1 this takes its  
origin only from pre-existing           
protoplasm4  ,all complex living bodies 
consist1 at one period of their         
existence1 of an aggregate of minute    
portions of such substance1 of similar  
structure1 called cells1 each cell      
having its own life independent of the  
others1 though influenced by them4  ,all
 the morphological characters of animals

 and plants are the results of the mode 
of multiplication1 growth1 and          
structural metamorphosis of these cells1
 considered as morphological units4     
,all the physiological activities of    
animals and plants--assimilation1       
secretion1 excretion1 motion1           
generation--are the expression of the   
activities of the cells considered as   
physiological units4 ,each individual1  
among the higher animals and plants1 is 
a synthesis of millions of subordinate  
individualities4 ,its individuality1    
therefore1 is that of a 'civitas' in the
 ancient sense1 or that of the          
,leviathan of ,hobbes4  ,there is no    
absolute line of demarcation between    
animals and plants4 ,the intimate       
structure1 and the modes of change1 in  
the cells of the two are fundamentally  
the same4 ,moreover1 the higher forms   
are evolved from lower1 in the course of
 their development1 by analogous        
processes of differentiation1           
coalescence1 and reduction in both the  

vegetable and the animal worlds4  ,at   
the present time1 the cell theory1 in   
consequence of recent investigations    
into the structure and metamorphosis of 
the 'nucleus1' is undergoing a new      
development of great significance1      
which1 among other things1 foreshadows  
the possibility of the establishment of 
a physical theory of heredity1 on a     
safer foundation than those which       
,buffon and ,darwin have devised4       
,sidenote3 ,spontaneous generation      
disproved4  ,the popular belief in      
abiogenesis1 or the so-called           
'spontaneous' generation of the lower   
forms of life1 which was accepted by all
 the philosophers of antiquity1 held its
 ground down to the middle of the       
seventeenth century4 ,notwithstanding   
the frequent citation of the phrase1    
wrongfully attributed to ,harvey1 ',omne
 vivum ex ovo1' that great physiologist 
believed in spontaneous generation as   
firmly as ,aristotle did4 ,and it was   
only in the latter part of the          

seventeenth century1 that ,redi1 by     
simple and well-devised experiments1    
demonstrated that1 in a great number of 
cases of supposed spontaneous           
generation1 the animals which made their
 appearance owed their origin to the    
ordinary process of reproduction1 and   
thus shook the ancient doctrine to its  
foundations4 ,in the middle of the      
eighteenth century1 it was revived1 in a
 new form1 by ,needham and ,buffon2 but 
the experiments of ,spallanzani enforced
 the conclusions of ,redi1 and compelled
 the advocates of the occurrence of     
spontaneous generation to seek evidence 
for their hypothesis only among the     
parasites and the lowest and minutest   
organisms4 ,it is just fifty years since
 ,schwann and others proved that1 even  
with respect to them1 the supposed      
evidence of abiogenesis was             
untrustworthy4  ,during the present     
epoch1 the question1 whether living     
matter can be produced in any other way 
than by the physiological activity of   

other living matter1 has been discussed 
afresh with great vigor2 and the problem
 has been investigated by experimental  
methods of a precision and refinement   
unknown to previous investigators4 ,the 
result is that the evidence in favor of 
abiogenesis has utterly broken down1 in 
every case which has been properly      
tested4 ,so far as the lowest and       
minutest organisms are concerned1 it has
 been proved that they never make their 
appearance1 if those precautions by     
which their germs are certainly excluded
 are taken4 ,and1 in regard to          
parasites1 every case which seemed to   
make for their generation from the      
substance of the animal1 or plant1 which
 they infest has been proved to have a  
totally different significance4 ,whether
 not-living matter may pass1 or ever    
has1 under any conditions1 passed into  
living matter1 without the agency of    
pre-existing living matter1 necessarily 
remains an open question2 all that can  
be said is that it does not undergo this

 metamorphosis under any known          
conditions4 ,those who take a monistic  
view of the physical world may fairly   
hold abiogenesis as a pious opinion1    
supported by analogy and defended by our
 ignorance4 ,but1 as matters stand1 it  
is equally justifiable to regard the    
physical world as a sort of dual        
monarchy4 ,the kingdoms of living matter
 and of not-living matter are under one 
system of laws1 and there is a perfect  
freedom of exchange and transit from one
 to the other4 ,but no claim to         
biological nationality is valid except  
birth4  ,sidenote3 ,morphology4  ,in the
 department of anatomy and development1 
a host of accurate and patient          
inquirers1 aided by novel methods of    
preparation1 which enable the anatomist 
to exhaust the details of visible       
structure and to reproduce them with    
geometrical precision1 have investigated
 every important group of living animals
 and plants1 no less than the fossil    
relics of former faun and flor4 ,an     

enormous addition has thus been made to 
our knowledge1 especially of the lower  
forms of life1 and it may be said that  
morphology1 however inexhaustible in    
detail1 is complete in its broad        
features4 ,classification1 which is     
merely a convenient summary expression  
of morphological facts1 has undergone a 
corresponding improvement4 ,the breaks  
which formerly separated our groups from
 one another1 as animals from plants1   
vertebrates from invertebrates1         
cryptogams from phanerogams1 have either
 been filled up1 or shown to have no    
theoretical significance4 ,the question 
of the position of man1 as an animal1   
has given rise to much disputation1 with
 the result of proving that there is no 
anatomical or developmental character by
 which he is more widely distinguished  
from the group of animals most nearly   
allied to him1 than they are from one   
another4 ,in fact1 in this particular1  
the classification of ,linnus has been  
proved to be more in accordance with the

 facts than those of most of his        
successors4  ,sidenote3 ,anthropology4  
,the study of man1 as a genus and       
species of the animal world1 conducted  
with reference to no other              
considerations than those which would be
 admitted by the investigator of any    
other form of animal life1 has given    
rise to a special branch of biology1    
known1 as ,anthropology1 which has grown
 with great rapidity4 ,numerous         
societies devoted to this portion of    
science have sprung up1 and the energy  
of its devotees has produced a copious  
literature4 ,the physical characters of 
the various races of men have been      
studied with a minuteness and accuracy  
heretofore unknown2 and demonstrative   
evidence of the existence of human      
contemporaries of the extinct animals of
 the latest geological epoch has been   
obtained1 physical science has thus been
 brought into the closest relation with 
history and with archology2 and the     
striking investigations which1 during   

our time1 have put beyond doubt the vast
 antiquity of ,babylonian and ,egyptian 
civilisation1 are in perfect harmony    
with the conclusions of anthropology as 
to the antiquity of the human species4  
,classification is a logical process    
which consists in putting together those
 things which are like and keeping      
asunder those which are unlike2 and a   
morphological classification1 of course1
 takes notes only of morphological      
likeness and unlikeness4 ,so long1      
therefore1 as our morphological         
knowledge was almost wholly confined to 
anatomy1 the characters of groups were  
solely anatomical2 but as the phenomena 
of embryology were explored1 the        
likeness and unlikeness of individual   
development had to be taken into        
account2 and1 at present1 the study of  
ancestral evolution introduces a new    
element of likeness and unlikeness which
 is not only eminently deserving of     
recognition1 but must ultimately        
predominate over all others4 ,a         

classification which shall represent the
 process of ancestral evolution is1 in  
fact1 the end which the labors of the   
philosophical taxonomist must keep in   
view4 ,but it is an end which cannot be 
attained until the progress of          
palontology has given us far more       
insight than we yet possess1 into the   
historical facts of the case4 ,much of  
the speculative 'phylogeny1' which      
abounds among my present contemporaries1
 reminds me very forcibly of the        
speculative morphology1 unchecked by a  
knowledge of development1 which was rife
 in my youth4 ,as hypothesis1 suggesting
 inquiry in this or that direction1 it  
is often extremely useful2 but1 when the
 product of such speculation is placed  
on a level with those generalisations of
 morphological truths which are         
represented by the definitions of       
natural groups1 it tends to confuse     
fancy with fact and to create mere      
confusion4 ,we are in danger of drifting
 into a new ',natur-,philosophie' worse 

than the old1 because there is less     
excuse for it4 ,boyle did great service 
to science by his ',sceptical ,chemist1'
 and ,i am inclined to think that1 at   
the present day1 a ',sceptical          
,biologist' might exert an equally      
beneficent influence4  ,sidenote3       
,physiology4  ,whoso wishes to gain a   
clear conception of the progress of     
physiology1 since #ahcg1 will do well to
 compare ,mller's ',physiology1' which  
appeared in #ahce1 and ,drapiez's       
edition of ,richard's ',nouveaux        
,elments de ,botanique1' published in   
#ahcg1 with any of the present handbooks
 of animals and vegetable physiology4   
,mller's work was a masterpiece1        
unsurpassed since the time of ,haller1  
and ,richard's book enjoyed a great     
reputation at the time2 but their       
successors transport one into a new     
world4 ,that which characterises the new
 physiology is that it is permeated by1 
and indeed based upon1 conceptions      
which1 though not wholly absent1 are but

 dawning on the minds of the older      
writers4  ,modern physiology sets forth 
as its chief ends3 ,firstly1 the        
ascertainment of the facts and          
conditions of cell-life in general4     
,secondly1 in composite organisms1 the  
analysis of the functions of organs into
 those of the cells of which they are   
composed4 ,thirdly1 the explication of  
the processes by which this local       
cell-life is directly1 or indirectly1   
controlled and brought into relation    
with the life of the rest of the cells  
which compose the organism4 ,fourthly1  
the investigation of the phenomena of   
life in general1 on the assumption that 
the physical and chemical processes     
which take place in the living body are 
of the same order as those which take   
place out of it2 and that whatever      
energy is exerted in producing such     
phenomena is derived from the common    
stock of energy in the universe4 ,in the
 fifth place1 modern physiology         
investigates the relation between       

physical and psychical phenomena1 on the
 assumption that molecular changes in   
definite portions of nervous matter     
stand in the relation of necessary      
antecedents to definite mental states   
and operations4 ,the work which has been
 done in each of the directions here    
indicated is vast1 and the accumulation 
of solid knowledge1 which has been      
effected1 is correspondingly great4 ,for
 the first time in the history of       
science1 physiologists are now in the   
position to say that they have arrived  
at clear and distinct1 though by no     
means complete1 conceptions of the      
manner in which the great functions of  
assimilation1 respiration1 secretion1   
distribution of nutriment1 removal of   
waste products1 motion1 sensation1 and  
reproduction are performed2 while the   
operation of the nervous system1 as a   
regulative apparatus1 which influences  
the origination and the transmission of 
manifestations of activity1 either      
within itself or in other organs1 has   

been largely elucidated4  ,sidenote3    
,practical value of physiological       
discovery4  ,i have pointed out1 in an  
earlier part of this chapter1 that the  
history of all branches of science      
proves that they must attain a          
considerable stage of development before
 they yield practical 'fruits2' and this
 is eminently true of physiology4 ,it is
 only within the present epoch1 that    
physiology and chemistry have reached   
the point at which they could offer a   
scientific foundation to agriculture2   
and it is only within the present epoch1
 that zoology and physiology have       
yielded any very great aid to pathology 
and hygiene4 ,but within that time1 they
 have already rendered highly important 
services by the exploration of the      
phenomena of parasitism4 ,not only have 
the history of the animal parasites1    
such as the tapeworms and the trichina1 
which infest men and animals1 with      
deadly results1 been cleared up by means
 of experimental investigations1 and    

efficient modes of prevention deduced   
from the data so obtained2 but the      
terrible agency of the parasitic fungi  
and of the infinitesimally minute       
microbes1 which work far greater havoc  
among plants and animals1 has been      
brought to light4 ,the 'particulate' or 
'germ' theory of disease1 as it is      
called1 long since suggested1 has       
obtained a firm foundation1 in so far as
 it has been proved to be true in       
respect of sundry epidemic disorders4   
,moreover1 it has theoretically         
justified prophylactic measures1 such as
 vaccination1 which formerly rested on a
 merely empirical basis2 and it has been
 extended to other diseases with        
excellent results4 ,further1 just as the
 discovery of the cause of scabies      
proved the absurdity of many of the old 
prescriptions for the prevention and    
treatment of that disease2 so the       
discovery of the cause of splenic fever1
 and other such maladies1 has given a   
new direction to prophylactic and       

curative measures against the worst     
scourges of humanity4 ,unless the       
fanaticism of philozoic sentiment       
overpowers the voice of philanthropy1   
and the love of dogs and cats supersedes
 that of one's neighbor1 the progress of
 experimental physiology and pathology  
will1 indubitably1 in course of time1   
place medicine and hygiene upon a       
rational basis4 ,two centuries ago      
,england was devastated by the plague2  
cleanliness and common sense were enough
 to free us from its ravages4 ,one      
century since1 small-pox was almost as  
great a scourge2 science1 though working
 empirically1 and almost in the dark1   
has reduced that evil to relative       
insignificance4 ,at the present time1   
science1 working in the light of clear  
knowledge1 has attacked splenic fever   
and has beaten it2 it is attacking      
hydrophobia with no mean promise of     
success2 sooner or later it will deal1  
in the same way1 with diphtheria1       
typhoid and scarlet fever4 ,to one who  

has seen half a street swept clear of   
its children1 or has lost his own by    
these horrible pestilences1 passing     
one's offspring through the fire to     
,moloch seems humanity1 compared with   
the proposal to deprive them of half    
their chances of health and life because
 of the discomfort to dogs and cats1    
rabbits and frogs1 which may be involved
 in the search for means of guarding    
them4  ,sidenote3 ,scientific           
exploration4  ,an immense extension has 
been effected in our knowledge of the   
distribution of plants and animals2 and 
the elucidation of the causes which have
 brought about that distribution has    
been greatly advanced4 ,the             
establishment of meteorological         
observations by all civilised nations1  
has furnished a solid foundation to     
climatology2 while a growing sense of   
the importance of the influence of the  
'struggle for existence' affords a      
wholesome check to the tendency to      
overrate the influence of climate on    

distribution4 ,expeditions1 such as that
 of the ,challenger1' equipped1 not for 
geographical exploration and discovery1 
but for the purpose of throwing light on
 problems of physical and biological    
science1 have been sent out by our own  
and other ,governments1 and have        
obtained stores of information of the   
greatest value4 ,for the first time1 we 
are in possession of something like     
precise knowledge of the physical       
features of the deep seas1 and of the   
living population of the floor of the   
ocean4 ,the careful and exhaustive study
 of the phenomena presented by the      
accumulations of snow and ice1 in polar 
and mountainous regions1 which has taken
 place in our time1 has not only        
revealed to the geologist an agent of   
denudation and transport1 which has     
slowly and quietly produced effects1    
formerly confidently referred to        
diluvial catastrophes1 but it has       
suggested new methods of accounting for 
various puzzling facts of distribution4 

,sidenote3 ,palontology4  ,palontology1 
which treats of the extinct forms of    
life and their succession and           
distribution upon our globe1 a branch of
 science which could hardly be said to  
exist a century ago1 has undergone a    
wonderful development in our epoch4 ,in 
some groups of animals and plants1 the  
extinct representatives1 already known1 
are more numerous and important than the
 living4 ,there can be no doubt that the
 existing ,fauna and ,flora is but the  
last term of a long series of equally   
numerous contemporary species1 which    
have succeeded one another1 by the slow 
and gradual substitution of species for 
species1 in the vast interval of time   
which has elapsed between the deposition
 of the earliest fossiliferous strata   
and the present day4 ,there is no       
reasonable ground for believing that the
 oldest remains yet obtained carry us   
even near the beginnings of life4 ,the  
impressive warnings of ,lyell against   
hasty speculations1 based upon negative 

evidence1 have been fully justified2    
time after time1 highly organised types 
have been discovered in formations of an
 age in which the existence of such     
forms of life had been confidently      
declared to be impossible4 ,the western 
territories of the ,united ,states alone
 have yielded a world of extinct animal 
forms1 undreamed of fifty years ago4    
,and1 wherever sufficiently numerous    
series of the remains of any given      
group1 which has endured for a long     
space of time1 are carefully examined1  
their morphological relations are never 
in discordance with the requirements of 
the doctrine of evolution1 and often    
afford convincing evidence of it4 ,at   
the same time1 it has been shown that   
certain forms persist with very little  
change1 from the oldest to the newest   
fossiliferous formations2 and thus show 
that progressive development is a       
contingent1 and not a necessary result1 
of the nature of living matter4         
,sidenote3 ,geology4  ,geology is1 as it

 were1 the biology of our planet as a   
whole4 ,in so far as it comprises the   
surface configuration and the inner     
structure of the earth1 it answers to   
morphology2 in so far as it studies     
changes of condition and their causes1  
it corresponds with physiology2 in so   
far as it deals with the causes which   
have effected the progress of the earth 
from its earliest to its present state1 
it forms part of the general doctrine of
 evolution4 ,an interesting contrast    
between the geology of the present day  
and that of half a century ago1 is      
presented by the complete emancipation  
of the modern geologist from the        
controlling and perverting influence of 
theology1 all-powerful at the earlier   
date4 ,as the geologist of my young days
 wrote1 he had one eye upon fact1 and   
the other on ,genesis2 at present1 he   
wisely keeps both eyes on fact1 and     
ignores the pentateuchal mythology      
altogether4 ,the publication of the     
',principles of ,geology' brought upon  

its illustrious author a period of      
social ostracism2 the instruction given 
to our children is based upon those     
principles4 ,whewell had the courage to 
attack ,lyell's fundamental assumption  
7which surely is a dictate of common    
sense7 that we ought to exhaust known   
causes before seeking for the           
explanation of geological phenomena in  
causes of which we have no experience4  
,but geology has advanced to its present
 state by working from ,lyell's,j axiom2
 and1 to this day1 the record of the    
stratified rocks affords no proof that  
the intensity or the rapidity of the    
causes of change has ever varied1       
between wider limits1 than those between
 which the operations of nature have    
taken place in the youngest geological  
epochs4  ,an incalculable benefit has   
accrued to geological science from the  
accurate and detailed surveys1 which    
have now been executed by skilled       
geologists employed by the ,governments 
of all parts of the civilised world4 ,in

 geology1 the study of large maps is as 
important as it is said to be in        
politics2 and sections1 on a true scale1
 are even more important1 in so far as  
they are essential to the apprehension  
of the extraordinary insignificance of  
geological perturbations in relation to 
the whole mass of our planet4 ,it should
 never be forgotten that what we call   
'catastrophes1' are1 in relation to the 
earth1 changes1 the equivalents of which
 would be well represented by the       
development of a few pimples1 or the    
scratch of a pin1 on a man's head4 ,vast
 regions of the earth's surface remain  
geologically unknown2 but the area      
already fairly explored is many times   
greater than it was in #ahcg2 and1 in   
many parts of ,europe and the ,united   
,states1 the structure of the           
superficial crust of the earth has been 
investigated with great minuteness4     
,the parallel between ,biology and      
,geology1 which ,i have drawn1 is       
further illustrated by the modern growth

 of that branch of the science known as 
,petrology1 which answers to ,histology1
 and has made the microscope as         
essential an instrument to the          
geological as to the biological         
investigator4  ,the evidence of the     
importance of causes now in operation   
has been wonderfully enlarged by the    
study of glacial phenomena2 by that of  
earthquakes and volcanoes2 and by that  
of the efficacy of heat and cold1 wind1 
rain1 and rivers as agents of denudation
 and transport4 ,on the other hand1 the 
exploration of coral reefs and of the   
deposits now taking place at the bottom 
of the great oceans1 has proved that1 in
 animal and plant life1 we have agents  
of reconstruction of a potency hitherto 
unsuspected4  ,there is no study better 
fitted than that of geology to impress  
upon men of general culture that        
conviction of the unbroken sequence of  
the order of natural phenomena1         
throughout the duration of the universe1
 which is the great1 and perhaps the    

most important1 effect of the increase  
of natural knowledge4   ,,the ,,end4    
,,footnotes3       ,a ,there are        
excellent remarks to the same effect in 
,zeller's ,philosophie der ,griechen1   
,theil ,,ii4 ,abth4 ii p4      #djg1 and
 in ,eucken's ,die ,methode der         
,aristotelischen1      ,forschung1 pp4  
#acf et seq4       ,b ,fresnel1 after a 
brilliant career of discovery in some   
of the most difficult regions of        
physico-mathematical      science1 died 
at thirty-nine years of age4 ,the       
following      passage of a letter from 
him to ,young 7written in ,november     
#ahbd71 quoted by ,whewell1 so aptly    
illustrates the spirit      which       
animates the scientific inquirer that ,i
 may cite it3            ',for a long   
time that sensibility1 or that vanity1  
which people call love of glory is munch
 blunted           in me4 ,i labor much 
less to catch the suffrages of          
the public than to obtain an inward     
approval which           has always been

 the mental reward of my efforts4       
,without doubt ,i have often wanted the 
spur of           vanity to excite me to
 pursue my researches in                
moments of disgust and discouragement4  
,but all the           compliments which
 ,i have received from ,m4,m4 ,arago1   
,de ,laplace1 or ,biot1 never gave me so
 much           pleasure as the         
discovery of a theoretical truth        
or the confirmation of a calculation by 
experiment4'       ,c ',mmorable exemple
 de l'impuissance des recherches        
collectives appliques  la dcouverte des 
vrits      nouvelles6' says one of the  
most distinguished of living            
,french savants of the corporate        
chemical work of the old      ,acadmie  
des ,sciences4 7,see ,berthelot1        
,science et      ,philosophie1 p4 #bja47
       ,d ,i am particularly indebted to
 my friend and colleague      ,professor
 ,rcker1 ,f4,r4,s41 for the many acute  
criticisms and      suggestions on my   
remarks respecting the ultimate problems

      of physics1 with which he has     
favored me1 and by which ,i      have   
greatly profited4       ,e ,i am aware  
that this proposition may be challenged4
 ,it      may be said1 for example1     
that1 on the hypothesis of              
,boscovich1 matter has no extension1    
being reduced to      mathematical      
points serving as centres of 'forces4'  
,but as      the 'forces' of the various
 centres are conceived to limit      one
 another's action in such a manner that 
an area around      each centre has an  
individuality of its own extension comes
      back in the form of that area4    
,again1 a very eminent                  
mathematician and physicist--the late   
,clerk ,maxwell--has      declared that 
impenetrability is not essential to our 
notions of matter1 and that two atoms   
may conceivably occupy      the same    
space4 ,i am loth to dispute any dictum 
of a      philosopher as remarkable for 
the subtlety of his intellect      as   
for his vast knowledge2 but the         

assertion that one and      the same    
point or area of space can have         
different      7conceivably opposite7   
attributes appears to me to violate     
the principle of contradiction1 which is
 the foundation not      only of        
physical science1 but of logic in       
general4 ,it means      that ,a can be  
not-,a4       ,f ',molecule' would be   
the more appropriate name for such a    
particle4 ,unfortunately1 chemists      
employ this term in a      special      
sense1 as a name for an aggregation of  
their      smallest particles1 for which
 they retain the designation of         
'atoms4'       ,g ',at present more     
organic analyses are made in a single   
day than were accomplished before       
,liebig's time in a whole               
year4'--,hofmann1 ,faraday ,lecture1 p4 
#df4       ,h ,in the preface to his    
,mcanique ,chimique ,m4 ,berthelot      
declares his object to be 'ramener la   
chimie tout entirre      444 aux mmes   
principes mcaniques qui rgissent dj les 

diverses branches de la physique4'      
,i ,this is the more curious1 as        
,ampre's hypothesis that      vibrations
 of molecules1 causing and caused by    
vibrations of      the ether1 constitute
 heat1 is discussed4 ,see vol4 ii4 p4   
#ehg1 #bnd ed4 ,in the ,philosophy of   
the ,inductive ,sciences1      #bnd ed41
 #ahdg1 p4 #bci1 ,whewell remarks1      
propos of      ,bacon's definition of   
heat1 'that it is an expansive1         
restrained motion1 modified in certain  
ways1 and exerted in      the smaller   
particles of the body2' that 'although  
the exact      nature of heat is still  
an obscure and controverted matter1     
the science of heat now consists of many
 important truths2      and that to none
 of these truths is there any           
approximation      in ,bacon's essay4'  
,in point of fact1 ,bacon's statement1  
however much open to criticism1 does    
contain a distinct      approximation to
 the most important of all the truths   
respecting heat which had been          

discovered when ,whewell      wrote4    
,j ,perhaps ,i ought rather to say      
,button's axiom4 ,for that      great   
naturalist and writer embodied the      
principles of sound      geology in a   
pithy phrase of the ,thoris de la       
,terre3      ',pour juger de ce qui est 
arriv1 et mme de ce qui      arrivera1  
nous n'avons qu' examiner ce qui        
arrive4'     ,,thomas ,h4 ,,huxley',s   
,,works4   ,,science ,,and ,,culture1   
,,and ,,other ,,essays4      #abmo4     
,cloth1 #a4ej4  ,,the ,,crayfish3 ,,an  
,,introduction ,,to ,,the ,,study ,,of  
,,zo,,logy4      ,with #hb              
,illustrations4 #abmo4 ,cloth1 #a4ge4   
,,science ,,primers3 ,,introductory4    
#ahmo4 ,flexible cloth1 #de cents4      
,,man',s ,,place ,,in ,,nature4         
#abmo4 ,cloth1 #a4be4  ,,on ,,the       
,,origin ,,of ,,species4      #abmo4    
,cloth1 #a4jj4  ,,more ,,criticisms ,,on
 ,,darwin1 ,,and ,,administrative       
,,nihilism4      #abmo4 ,limp cloth1 #ej
 cents4  ,,manual ,,of ,,the ,,anatomy  

,,of ,,vertebrated ,,animals4           
,illustrated4 #abmo4 ,cloth1 #b4ej4     
,,manual ,,of ,,the ,,anatomy ,,of      
,,invertebrated ,,animals4      #abmo4  
,cloth1 #b4ej4  ,,lay ,,sermons1        
,,addresses1 ,,and ,,reviews4      #ab  
mo4 ,cloth1 #a4ge4  ,,critiques ,,and   
,,addresses4      #abmo4 ,cloth1 #a4ej4 
,,american ,,addresses2 ,,with ,a       
,,lecture ,,on ,,the ,,study ,,of       
,,biology4      #abmo4 ,cloth1 #a4be4   
,,physiography3 ,,an ,,introduction ,,to
 ,,the ,,study ,,of ,,nature4      ,with
 ,illustrations and ,colored ,plates4   
#abmo4 ,cloth1 #b4ej4  ,,huxley ,,and   
,,youmans',s ,,elements ,,of            
,,physiology ,,and ,,hygiene4      ,by  
,t4,h4 ,,huxley and ,w4,j4 ,,youmans4   
#abmo4 ,cloth1 #a4ej4     ,,john        
,,tyndall',s ,,works4   ,,essays ,,on   
,,the ,,floating ,,matter ,,of ,,the    
,,air1 in ,relation to ,putrefaction and
 ,infection4      #abmo4 ,cloth1 #a4ej4 
,,on ,,forms ,,of ,,water1 in ,clouds1  
,rivers1 ,ice1 and ,glaciers4      ,with

 #ce ,illustrations4 #abmo4 ,cloth1     
#a4ej4  ,,heat ,,as ,a ,,mode ,,of      
,,motion4 ,new edition4      #abmo4     
,cloth1 #b4ej4  ,,on ,,sound3 ,a ,course
 of ,eight ,lectures delivered at the   
,royal ,institution of ,great ,britain4 
,illustrated4 #abmo4 ,new edition4      
,cloth1 #b4jj4  ,,fragments ,,of        
,,science ,,for ,,unscientific ,,people4
      #abmo4 ,new revised and enlarged  
edition4 ,cloth1 #b4ej4  ,,light ,,and  
,,electricity4      #abmo4 ,cloth1      
#a4be4  ,,lessons ,,in ,,electricity1   
#ahge-'gf4      #abmo4 ,cloth1 #a4jj4   
,,hours ,,of ,,exercise ,,in ,,the      
,,alps4      ,with ,illustrations4      
#abmo4 ,cloth1 #b4jj4  ,,faraday ,,as ,a
 ,,discoverer4 ,a ,memoir4      #abmo4  
,cloth1 #a4jj4  ,,contributions ,,to    
,,molecular ,,physics in the ,domain of 
,radiant ,heat4      #e4jj4  ,,six      
,,lectures ,,on ,,light4 ,delivered ,in 
,america in #ahgb-'gc4      ,with an    
,appendix and numerous ,illustrations4  
,cloth1 #a4ej4  ,,address delivered     

before the ,british ,association1       
assembled at ,belfast4 ,revised with    
,additions4      #abmo4 ,paper1 #ej     
cents4  ,,researches ,,on ,,diamagnetism
 ,,and ,,magnecrystallic ,,action1      
including the ,question of ,diamagnetic 
,polarity4 ,with ,ten ,plates4          
#abmo1 cloth4 ,price1 #a4ej4            
,,charles ,,darwin',s ,,works4          
,,origin ,,of ,,species ,,by ,,means    
,,of ,,natural ,,selection1 ,,or ,,the  
,,preservation ,,of ,,favored ,,races   
,,in ,,the ,,struggle ,,for ,,life4     
,from sixth and last ,london edition4   
#b vols41 #abmo4 ,cloth1 #d4jj4         
,,descent ,,of ,,man1 ,,and ,,selection 
,,in ,,relation ,,to ,,sex4 ,with many  
,illustrations4 ,a new edition4         
#abmo4 ,cloth1 #c4jj4  ,,journal ,,of   
,,researches ,,into ,,the ,,natural     
,,history ,,and ,,geology ,,of          
,,countries ,,visited ,,during ,,the    
,,voyage ,,of ,h4,m4,s4 ,,beagle ,,round
 ,,the ,,world4 ,new edition4           
#abmo4 ,cloth1 #b4jj4  ,,emotional      

,,expressions ,,of ,,man ,,and ,,the    
,,lower ,,animals4      #abmo4 ,cloth1  
#c4ej4  ,,the ,,variations ,,of         
,,animals ,,and ,,plants ,,under        
,,domestication4 ,with a ,preface1 by   
,professor ,,asa ,,gray4      #b vols4  
,illustrated4 ,cloth1 #e4jj4            
,,insectivorous ,,plants4      #abmo4   
,cloth1 #b4jj4  ,,movements ,,and       
,,habits ,,of ,,climbing ,,plants4      
,with ,illustrations4 #abmo4 ,cloth1    
#a4be4  ,,the ,,various ,,contrivances  
,,by ,,which ,,orchids ,,are            
,,fertilized ,,by ,,insects4            
,revised edition1 with ,illustrations4  
#abmo4 ,cloth1 #a4ge4  ,,the ,,effects  
,,of ,,cross ,,and ,,self               
,,fertilization ,,in ,,the ,,vegetable  
,,kingdom4      #abmo4 ,cloth1 #b4jj4   
,,different ,,forms ,,of ,,flowers ,,on 
,,plants ,,of ,,the ,,same ,,species4   
,with ,illustrations4      #abmo4       
,cloth1 #a4ej4  ,,the ,,power ,,of      
,,movement ,,in ,,plants4 ,by ,,charles 
,,darwin1 ,,ll4,d41 ,f4,r4,s41 assisted 

by ,,francis ,,darwin4      ,with       
,illustrations4 #abmo4 ,cloth1 #b4jj4   
,,the ,,formation ,,of ,,vegetable      
,,mould ,,through ,,the ,,action ,,of   
,,worms4 ,with ,observations on their   
,habits4      ,with ,illustrations4     
#abmo4 ,cloth1 #a4ej4     ,,alexander   
,,bain',s ,,works4   ,,the ,,senses     
,,and ,,the ,,intellect4 ,by ,,alexander
 ,,bain4 ,,ll4,d41 ,professor of ,logic 
in the ,university of ,aberdeen4        
#hvo4 ,cloth1 #e4jj4      ,the object of
 this treatise is to give a full and    
systematic      account of two principal
 divisions of the science of mind--the  
senses and the intellect4 ,the value of 
the third edition of the      work is   
greatly enhanced by an account of the   
psychology of      ,aristotle1 which has
 been contributed by ,mr4 ,grote4  ,,the
 ,,emotions ,,and ,,the ,,will4 ,by     
,,alexander ,,bain1 ,,ll4,d4      #hvo4 
,cloth1 #e4jj4      ,the present        
publication la a sequel to the former   
one on ,the      ,senses and the        

,intellect1 and completes a systematic  
exposition      of the human mind4      
,,mental ,,science4 ,a ,compendium of   
,psychology and the ,history of         
,philosophy4 ,designed as a ,text-book  
for ,high-,schools and ,colleges4 ,by   
,,alexander ,,bain1 ,,ll4,d4      #abmo4
 ,cloth1 leather back1 #a4ej4      ,this
 present volume is an abstract of two   
voluminous works1 ,the      ,senses and 
the intellect and ,the ,emotions and the
 ,will1 and      presents in a          
compressed and lucid form the views     
which are there      more extensively   
elaborated4  ,,moral ,,science4 ,a      
,compendium of ,ethics4 ,by ,,alexander 
,,bain1 ,,ll4,d4      #abmo4 ,cloth1    
leather back1 #a4ej4      ,the present  
dissertation falls under two divisions4 
,the first      division entitled ,the  
,theory of ,ethics1 gives an account of 
the      questions or points brought    
into discussion1 and handles at         
length the two of greatest prominence1  
the ,ethical ,standard and      the     

,moral ,faculty4 ,the second            
division--on the ,ethical               
,systems--is a full detail of all the   
systems1 ancient and modern4  ,,mind    
,,and ,,body4 ,theories of their        
,relations4 ,by ,,alexander ,,bain1     
,,ll4,d4      #abmo4 ,cloth1 #a4ej4     
,a forcible statement of the connection 
between mind and body1      studying    
their subtile interworkings by the light
 of the most      recent physiological  
investigations4--,christian ,register4  
,,logic1 ,,deductive ,,and ,,inductive4 
,by ,,alexander ,,bain1 ,,ll4,d4        
,revised edition1 #abmo4 ,cloth1 leather
 back1 #b4jj4  ,,education ,,as ,a      
,,science4 ,by ,,alexander ,,bain1      
,,ll4,d4      #abmo4 ,cloth1 #a4ge4     
,,english ,,composition ,,and           
,,rhetoric4 ,enlarged edition4 ,part ,i4
 ,intellectual ,elements of ,style4 ,by 
,,alexander ,,bain1 ,,ll4,d41 ,emeritus 
,professor of ,logic in the ,university 
of ,aberdeen4      #abmo4 ,cloth1       
leather back1 #a4ej4  ,,on ,,teaching   

,,english4 ,with ,detailed ,examples and
 an ,inquiry into the ,definition of    
,poetry ,by ,,alexander ,,bain1 ,,ll4,d4
      #abmo4 ,cloth1 #a4be4  ,,practical
 ,,essays4 ,by ,,alexander ,,bain1      
,,ll4,d4      #abmo4 ,cloth1 #a4ej4     
,established by ,,edward ,l4 ,,youmans4 
,,the ,,popular ,,science ,,monthly1    
,edited by ,w4,j4 ,,youmans1   ,is      
filled with scientific articles by      
well-known writers on subjects of       
popular and practical interest4 ,its    
range of topics1 which is widening with 
the advance of science1 comprises3      
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and ,education4 ,relations      of      
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volume ,,xxxii1 which begins with the   
number for ,november1 #ahhg1 ,professor 
,joseph ,le ,conte will discuss the     
,relations of ,evolution and ,religion1 
and the ,hon4 ,david ,a4 ,wells will    
continue his valuable papers on ,recent 
,economic ,disturbances4 ,the volume    
will also contain illustrated articles  
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the ,applications of ,science2 and will 
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other distinguished writers4  ,it       
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