338 THE BIOLOGICAL SCIENCES AND MEDICINE. [LECT. 



the death of Descartes, he did not contribute much to 

 their realisation. But, for the next century, all pro- 

 gress in physiology took place along the lines which 

 Descartes laid down. 



The greatest physiological and pathological work 

 of the seventeenth century, Borelli's treatise "De 

 Motu Animalium," is, to all intents and purposes, a 

 development of Descartes' fundamental conception ; 

 and the same may be said of the physiology and 

 pathology of Boerhaave, whose authority dominated 

 in the medical world of the first half of the eighteenth 

 century. 



With the origin of modern chemistry, and of 

 electrical science, in the latter half of the eighteenth 

 century, aids in the analysis of the phenomena of life, 

 of which Descartes could not have dreamed, were 

 offered to the physiologist. And the greater part of 

 the gigantic progress which has been made in the 

 present century is a justification of the prevision of 

 Descartes. For it consists, essentially, in a more and 

 more complete resolution of the grosser organs of the 

 living body into physico-chemical mechanisms. 



" I shall try to explain our whole bodily machinery 

 in such a way, that it will be no more necessary for 

 us to suppose that the soul produces such movements 

 as are not voluntary, than it is to think that there is 

 in a clock a soul which causes it to show the hours." 1 

 These words of Descartes might be appropriately taken 

 as a motto by the author of any modern treatise on 

 physiology. 



1 " De la Formation du Foetus." 



