396 



SCIENTIFIC THOUGHT. 



" Division of the " Physiological Division of Labour," the happy ex- 



Physiologi- 



cai Labour." pression invented by the great French zoologist, Henri 

 Milne-Edwards. 



Whilst Liebig was working at the great problems of 

 the economy of life, and making chemistry subservient 

 to the interests of agriculture, physiology, and pathology, 

 another influence was exerted mainly in Germany on 

 the study of the processes which take place in the living 

 organism. This influence had its source in an application 

 of the principles of dynamics and the more modern teach- 

 ings of physics. 1 It emanated from two distinct centres 

 from Leipzig, where the brothers Weber 2 taught how to 



1 In many passages of his inter- 

 esting and brilliant " Addresses " 

 Du Bois-Reymond has dwelt on 

 the great revolution which came 

 over physiological studies about the 

 middle of the century, characteris- 

 ing it as a special German achieve- 

 ment. Claude Bernard has given 

 us an interesting account of a 

 corresponding, but not identical, 

 change of ideas in the great medical 

 schools of Paris. Quite recently Sir 

 Michael Foster has created in this 

 country an interest in the history 

 of medicine, notably of physiology, 

 and has on various occasions given 

 us masterly summaries of the results 

 of his historical research. I may 

 refer specially to his very lucid and 

 fascinating monograph on Claude 

 Bernard (London, 1899, in Fisher 

 Unwin's ' Masters of Medicine ' 

 Series). Another authority in 

 modern physiology, Prof. M'Ken- 

 drick of Glasgow, has treated in a 

 companion volume of Helmholtz, 

 dwelling mainly on his physiological 

 labours, based upon his brilliant 

 application of physics and mathe- 

 matics. The two monographs ex- 

 hibit very clearly two distinct in- 

 fluences which have been at work 



in remodelling the science of phy- 

 siology and the conceptions of the 

 phenomena of life. 



- Regarding the position and in- 

 fluence of the three brothers Weber, 

 I may refer to former passages of this 

 history (vol. i. p. 196; vol. ii. chap. vi. 

 passim). The greatest of the three 

 Ernst Heinrich Weber (1795-1878) 

 occupies a unique position in the 

 development of the " science of life " 

 in Germany. He seems never to 

 have come under the influence of 

 the then prevalent " philosophy of 

 nature," and he had accordingly, 

 unlike Lie"big and Johannes Miiller, 

 nothing to unlearn. See on this 

 point Du Bois-Reymond's Eloge of 

 Muller in ' Rerlen ' (vol. ii. p. 216), 

 also Ludwig's Eloge of Weber (Leip- 

 zig, 1878, p. 10). Weber represents 

 in the purest form the influence 

 which physics, based upon experi- 

 ment and measurement, had upon 

 the development of the study of 

 organic form and function, as Liebig 

 represents in the purest form the 

 influence of chemical research and 

 reasoning. In this respect Liebig 

 was more nearly related to the 

 Paris school, Weber to the Berlin 

 school, which he greatly influenced. 



