THE DEEPENING OF PHYSIOLOGY. 285 



shorthand was frankly anthropomorphic or spiritual- 

 istic ; they invoked " animal spirits " and '^ vital 

 spirits," " principles of life " and " vires form- 

 ativce/' "humours" and "temperaments." It is 

 difficult to see how it could have been otherwise. 



But as inquisitiveness became gradually more pen- 

 etrating, as the organs of the body were disclosed in 

 many other creatures besides man, as the uses of 

 many of them were in part discovered, the spirit- 

 ualistic formulae began to appear somewhat gratui- 

 tous. Thus it is interesting to note that Mariotte 

 (d. 1684), who compared the entrance of water into 

 the roots of plants to its rise in capillary tubes, — a 

 shrewd suggestion — was one of the first to discard the 

 hypothesis of " a vegetable soul " — as a factor in the 

 plant's every-day functions. • Harvey's demonstra- 

 tion of some of the factors in the circulation of the 

 blood may be taken as one of the first of the long 

 series of attempts to express vital phenomena in terms 

 of mechanism — attempts which put an end to the 

 reign of spirits, though not to the intrusion of meta- 

 physics. The great work of Haller (1708-1777) — 

 Elementa Pliysiologice Corporis Humani — represents 

 the position of the study of the functions of the 

 organs of the body at the beginning of the nineteenth 

 century, and it is marked by its endeavour to reject 

 all. that could not be verified by observation and ex- 

 periment. 



When we pass from the work of Haller to that of 

 Johannes Miiller (1801-1858) we feel at once in a 

 new century. Chemistry and physics had made 

 great strides, and he calls them to his aid in his phys- 

 iological work. Man was no longer studied alone, 

 for Miiller's physiology was essentially comparative. 

 The facts of mental life were no longer kept wholly 



