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 philosophy " — 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 mathematical treatment 

 or of experimental treatment, or of both, a broad 

 distinction was drawn between the experimental 

 branches of what had previously been called natu- 

 ral history and the observational branches — those 

 in which experiment was (or appeared to be) of 

 doubtful use, and where, at that time, mathemat- 

 ical methods were inapplicable. Under these cir- 

 cumstances the old name of " Xatural History " 

 stuck by the residuum by those phenomena 



