STEPHEN HALES 119 



what of a solitary figure, standing between what 

 may be called the periods of Boyle and of Cavendish. 

 This is even more striking in his botanical position, 

 for here he stands in the solitude of all great original 

 inquirers. We must go back to Van Helmont, 

 1577 — 1644, to find anyone comparable to him as 

 an experimentalist. His successors have dis- 

 covered much that was hidden from him, but 

 consciously or unconsciously they have all learned 

 from him the true method and spirit of physio- 

 logical work. 



It may be urged that in exalting Hales I am 

 unfair to Malpighi. It may be fairer to follow 

 Sachs in linking these great men together, and to 

 insist on the wonderful fact that before Malpighi 's 

 book in 1671, vegetable physiology was still where 

 Aristotle left it, whereas 56 years later, in 1727, we 

 find in Hales' book an experimental science in the 

 modern sense. 



It should not be forgotten that students of 

 animal physiology agree with botanists as to Hales' 

 greatness. A writer in the Encyclopoedia Britannica 

 speaks of him as "the true founder of the modern 

 experimental method in physiology." 



According to Sachs, Ray made some interest- 

 ing observations on the transmission of water, but 

 on the whole what he says on this subject is 

 not important. There is no evidence that Ray 

 influenced Hales. 



Mariotte, the physicist, came to one physio- 

 logical conclusion of great weight^ ; namely, that 



' Sachs, GescMchte, p. 502. Malpighi held similar views. 



