ii8 STEPHEN HALES 



Sciences^ that the Iphysiologist asks questions 

 of Nature in a sense differing from that of the 

 physicist. The Why? of the physicist meant 

 Through what causes? that of the physiologist — to 

 what end? This distinction no longer holds good, 

 and if it is to be appUed to Hales it is a test which 

 shows him to be a physicist. For, as Sachs shows, 

 though Hales was necessarily a teleologist in the 

 theological sense, he always asked for purely 

 mechanical explanations. He was the most un- 

 vitahstic of physiologists, and I think his explana- 

 tions suffered from this cause. For instance, he 

 seems to have held that to compare the effect of 

 heat on a growing root to the action of the same 

 cause on a thermometer^ was a quite satisfactory 

 proceeding. And there are many other passages 

 in Vegetable Staticks where one feels that his 

 speculations are too heavy for his knowledge. 



Something must be said of Hales' relation to 

 his predecessors and successors in botanical work. 

 The most striking of his immediate predecessors 

 were Malpighi 1628 — 1694, Grew i028 — 171 1, Ray 

 1627 — 1705, and Mariotte (birth unknown, died 

 1684) ; and of these the three first were born one 

 hundred years before the publication of Vegetable 

 Staticks. Malpighi and Grew were essentially 

 plant-anatomists, though both dealt in physio- 

 logical speculations. Their works were known to 

 Hales, but they do not seem to have influenced him. 



We have seen that as a chemist Hales is sbme- 



» 1837, III. p. 389. 



' Vegetable Static/is, p. 346. 



