78 WOODWARD 



which capitalists can be persuaded to invest in a " Keely motor " 

 or in anything that promises the marvelous. 



With the decline of alchemy the field for chemistry shifted 

 somewhat. Not unnaturally, since most chemists were also 

 physicians in those days, a knowledge of the chemical properties 

 of substances came to occupy a prominent place in the physi- 

 cian's art. Thus Paracelsus in the sixteenth century, cutting 

 loose from the teachings of Aristotle and Galen, boldly asserted 

 that the true use of chemistry is not to make gold but to pre- 

 pare medicine ; and he and his follower Van Helmont, in addi- 

 tion to attaining fame for skill in compounding remedies, were 

 amongst the first to appreciate the true import of the processes of 

 analysis and synthesis which came to be called in their day the 

 spagyric art. Then followed the doctrine of the mutually neu- 

 tralizing substances, acid and alkali ; the fruitful hypothesis of 

 elective attractions or affinities ; the ingenious, if erroneous, 

 theory of phlogiston, and the more permanent theory of 

 oxygen. All these led up through more and more searching- 

 experimentation to the first great epoch in the history of chem- 

 istry — the epoch of Lavoisier. 



Among the early workers in the century preceding the epoch 

 of Lavoisier the names of Becher and his disciple Stahl deserve 

 especial mention, not only by reason of their introduction of the 

 theory of phlogiston, but also by reason of their enthusiastic 

 and steadfast devotion to science without hope of pecuniary re- 

 ward. In his remarkable treatise entitled " Physica Subter- 

 raneae," published in 1681, Becher defends the scientific pursuit 

 of chemistry as not less worthy of attention than philosophical 

 and theological studies. He insists especially on the need of 

 careful observations and on the necessity of constantly verify- 

 ing theory by experiment. With true scientific enthusiasm he 

 describes the chemist as one willing to work amid the flames 

 and fumes, and, if need be, the poisons and poverty of the 

 laboratory. He has no patience with the charlatans, of which it 

 appears there were still many in his day, who are looking chiefly 

 for ways and means of extracting the precious from the baser 

 metals. As for himself he says, " My kingdom is not of this 



