X ON THE STUDY OF BIOLOGY 265 



published hereafter, showed that precise mathe- 

 matical methods were applicable to those branches 

 of science such as astronomy, and what we now 

 call physics, which occupy a very large portion of 

 the domain of what the older writers understood 

 by natural history. And inasmuch as the partly 

 deductive and partly experimental methods of 

 treatment to which Newton and others subjected 

 these branches of human knowledge, showed 

 that the phenomena of nature which belonged 

 to them were susceptible of explanation, and 

 thereby came within the reach of what was called 

 " philosophy " in those days ; so much of this 

 kind of knowledge as was not included under 

 astronomy came to be spoken of as " natural philo- 

 sophy " a term which Bacon had employed in 

 a much wider sense. Time went on, and yet 

 other branches of science developed themselves. 

 Chemistry took a definite shape ; and since all these 

 sciences, such as astronomy, natural philosophy, 

 and chemistry, were susceptible either of mathe- 

 matical treatment or of experimental treatment, 

 or of both, a broad distinction was drawn between 

 the experimental branches of what had previously 

 been called natural history and the observational 

 branches those in which experiment was (or 

 appeared to be) of doubtful use, and where, at 

 that time, mathematical methods were inapplic- 

 able. Under these circumstances the old name 

 of " Natural History " stuck by the residuum, by 



