THE SUCCESSORS OF GALILEO 



Boyle was led to believe that there were many " latent 

 qualities" due to substances contained in it that 

 science had as yet been unable to fathom, believing 

 that there is "not a more heterogeneous body in the 

 world." He believed that contagious diseases were 

 carried by the air, and suggested that eruptions of 

 the earth, such as those made by earthquakes, might 

 send up "venomous exhalations" that produced 

 diseases. He suggested also that the air might play 

 an important part in some processes of calcination, 

 which, as we shall see, was proved to be true by La- 

 voisier late in the eighteenth century. Boyle's no- 

 tions of the exact chemical action in these phenomena 

 were of course vague and indefinite, but he had ob- 

 served that some part was played by the air, and he 

 was right in supposing that the air "may have a great 

 share in varying the salts obtainable from calcined 

 vitriol." 5 



Although he was himself such a painstaking ob- 

 server of facts, he had the fault of his age of placing 

 too much faith in hear-say evidence of untrained ob- 

 servers. Thus, from the numerous stories he heard 

 concerning the growth of metals in previously ex- 

 hausted mines, he believed that the air was respon- 

 sible for producing this growth in which he un- 

 doubtedly believed. The story of a tin -miner that, 

 in his own time, after a lapse of only twenty-five 

 years, a heap of earth previously exhausted of its 

 ore became again even more richly impregnated than 

 before by lying exposed to the air, seems to have been 

 believed by the philosopher. 



As Boyle was an alchemist, and undoubtedly be- 



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