2o THE POPULAR SCIENCE MONTHLY 



rated a new epoch in chemistry by his remarkably sane and sound criti- 

 cisms of the chemical thought and theories of the time. Boyle was a 

 broadly and thoroughly trained scholar of the time, and prominent in 

 many lines of activity. He was one of the founders of the Royal So- 

 ciety of England and at one time its president. He was also a man of 

 wealth, but his main interest was in experimenting in chemistry and 

 physics, and many notable observations stand to his credit. Every 

 student of chemistry or physics knows of Boyle's law of gases. 



It is not, however, by his experimental work — valuable as it was — 

 that he exerted the greatest influence, but rather by his extended and 

 frecjuent careful and scientific criticisms of the prevalent chemical theo- 

 ries, both the Aristotelian and Paracelsan theories, of the nature of 

 substances and matter. Particularly by his work published in 1G61 

 entitled "The Sceptical Chymist,'" in which, rather verbosely, but with 

 great thoroughness and yet with great tolerance and patience, he sub- 

 mits the theories of the time to really constructive criticism. By a 

 wealth of facts and experimental illustrations he demonstrates the 

 purely metaphysical character of both the prevalent theories, and grad- 

 ually develops the only consistent concept of an element which was 

 possible for his time — namely, any substance which no experimental 

 evidence could show to be reducible to simpler substances. He makes 

 indeed, no attempt to say that any particular known substance is indeed 

 an element in the sense of his characterization, though one might infer 

 from his discussion that gold and silver were as well deserving of the 

 title as any substances known to him, as he has never been able to 

 obtain anything else from them or to know of any reliable experiments 

 with such results. Unlike Paracelsus, or Glauber, or Van Helmont, or 

 their imitators, Boyle was no dogmatist, being slow to assert and yet 

 open-minded to any facts and very respectful to the opinions of others, 

 though not in the least dominated by them. 



The " Sceptical Chymist" of Boyle, as well as others of his writings, 

 had a very wide circulation throughout the continent as well as in Great 

 Britain, and his sane and persuasive reasoning, free from mysticism, 

 and based on legitimate inferences from observed facts, made a great 

 impression upon scientific men. While he offered no theory to replace 

 the discredited Aristotelian and Paracelsan theories of the constitution 

 of matter, he transferred the emphasis of chemical thought horn a priori 

 speculation to rational deductions from observed phenomena, and, 

 though these might often be imperfect or mistaken, yet chemical rea- 

 soning was launched upon a course which could only lead to clearer 

 understanding and to more soundly established theories. 



The century following Boyle may be well characterized as the phlo- 

 gistic period, because the representative chemists of that period were 

 largely occupied in systematizing chemical actions with reference to 

 that theory. 



