260 A SHORT HISTORY OF SCIENCE 



toward the modern experimental period of chemistry, of which he 

 and Van Helmont are the pioneers. Neither, however, while work- 

 ing on air greatly advanced our ideas of atmospheric chemistry. 



The atmosphere in its relation to combustion and respiration was 

 further studied by an English physician, Dr. John Mayow (1645- 

 1679), who made many experiments upon the shrinkage of air- 

 volume during the burning of camphor and other substances and 

 during the confinement of mice under a bell-glass. The dying of 

 the mice and the cessation of the combustion, which after a time 

 ensued, he attributed to the exhaustion of some ingredient in the 

 air indispensable to life and combustion. This ingredient, which 

 we now call oxygen, Mayow named "fire-air." 



Very soon, however, a new theory of combustion (and as it 

 turned out a false theory) began to absorb the attention of 

 natural philosophers. 



FROM ALCHEMY TO CHEMISTRY. The saying is attributed to 

 Liebig that "Alchemy was never at any time different from 

 chemistry." In one sense this is undoubtedly true. The search 

 for "the philosopher's stone," "the elixir of life," "potable gold," 

 and the "transmutation of metals," consisted of necessity in the 

 use of processes such as boiling, baking, wetting, drying, evaporat- 

 ing, condensing, burning, calcifying, decalcifying, acidifying, 

 freezing, melting, and the like, mostly tending towards chemical 

 changes and the formation of new mixtures and compounds. But 

 even if Liebig's saying were true, chemistry has passed through 

 three principal stages ; viz. first, purely empirical experimenting, 

 mostly for practical purposes, whether metallurgical or other; 

 second, an iatro-chemical or medico-chemical phase ; and finally 

 the really scientific period of to-day, the way for which may be 

 said to have been cleared by the Sceptical Chymist of Robert 

 Boyle, 1 first published in English in Oxford in 1661. In this re- 



1 The Hon. Robert Boyle was one of the most active, perhaps the most so, of 

 that remarkable group of scientific investigators who, in the reign of Charles II., 

 raised England to the foremost place among European nations in the pursuit of 

 ecience, and gave their period a renown which has caused it to be often spoken of, 

 and very justly, as the classical age of English science. . . . Boyle had been since 

 1646 engaged in chemical researches in London, being then connected with the earlier 



