74 Presidential Address 



that time, even the greatest biologists e.g., 

 J. M tiller recognised that the knowledge bio- 

 logists possessed both of vital and physical 

 phenomena was insufficient to refer both to a 

 common measure. The method, therefore, was 

 to study the processes of life in relation to each 

 other only. Since that time it has become 

 fundamental in our science not to regard any 

 vital process as understood at all unless it can 

 be brought into relation with physical standards, 

 and the methods of physiology have been based 

 exclusively on this principle. The most efficient 

 cause [conducing to the change] was the progress 

 which had been made in physics and chemistry, 

 and particularly those investigations which led 

 to the establishment of the doctrine of the Con- 

 servation of Energy. ...- . . 



Investigators who are now working with such 

 earnestness in all parts of the world for the ad- 

 vance of physiology, have before them a definite 

 and well-understood purpose, that purpose being 

 to acquire an exact knowledge of the chemical 

 and physical processes of animal life and of the 

 self-acting machinery by which they are regu- 

 lated for the general good of the organism. The 

 more singly and straightforwardly we direct our 

 efforts to these ends, the sooner we shall attain 

 to the still higher purpose the effectual applica- 

 tion of our knowledge for the increase of human 

 happiness. 



