LECTURE V. 



VAN HELMONT AND THE RISE OF CHEMICAL 

 PHYSIOLOGY. 



In the work of the physiologist of to-day the teachings of 

 chemistry are held, and rightly held, in high esteem. Though 

 many problems in physiology may still be regarded, and, it may 

 be, will always have to be regarded as purely physiological 

 problems, as problems to be solved in their own way and by 

 no other means, yet a preponderating number, perhaps also an 

 increasing number of the problems on which the physiologist 

 is to-day engaged, are at bottom chemical or physical problems, 

 problems to be solved by the application of chemical or physical 

 methods to the phenomena of living beings. 



In a previous lecture I spoke of the influence on the 

 progress of physiology exerted by the new physical learning 

 which came into power in the early years of the seventeenth 

 century; it was then that physics and physiology touched 

 hands. I now propose to speak of the way in which chemistry 

 came to the aid of those who were inquiring into the problems 

 of life, and thus gave rise to the chemical physiology which we 

 know to-day. 



The physiology of Vesalius and his school consisted as we 

 have seen of deductions from the data of anatomical arrange- 

 ments confirmed or corrected by experiments on living animals. 

 From time to time Vesalius made use of the growing mechanical 

 knowledge of his age, and we trace here and there the influence 

 of the as yet imperfect physical conceptions then dominant. 

 But of chemistry as we now know it there is hardly a word. 



