A WORLD OF CHANGE — WEIDLEIN 189 



taught that all substances were composed of some sort of primordial 

 stuff in combination with various amounts of the four elementary- 

 properties. 



Out of Aristotle's doctrine of the elements grew the fascinating but 

 futile work of the alchemists, who dreamed vainly of converting base 

 metals into valuable gold. But, though futile, the efforts of the al- 

 chemists were not altogether fruitless. Modern chemistry had its 

 beginnings in the mystical vaporings that characterized their gloomy, 

 dimly lighted workshops, full of strange vessels, spheres, portions of 

 skeletons hanging from the ceiling and massive parchment books 

 covered with hieroglyphics. Alchemy may be compared to the man 

 who told his sons that he had left them gold buried somewhere in his 

 vineyard. The sons dug deeply and earnestly, but found no gold. 

 Their cultivation of the soil, however, produced a plentiful vintage. 

 Similarly, the earnest but unsuccessful search for the transmutation of 

 base metals into gold brought to light many useful discoveries and 

 instructive experiments. 



These by-products of alchemy — chance discoveries of chemical 

 elements, compounds and principles — were more important than the 

 search for artificial gold. 



The first investigator to grasp the significance of the value of 

 chemistry as a separate science was Robert Boyle, whose publication 

 of The Skyptical Chymist in 1661 is often regarded as marking the 

 beginning of modern chemistry. Paracelsus, celebrated by Robert 

 Browning, broke with the monks and alchemists, assailed the physi- 

 cians who treated chickenpox with the aid of a soup made of the hearts 

 and livers of vipers, and laid crudely the foundation of modern medical 

 chemistry. Becher conceived of phlogiston as the active principle of 

 fire. The downfall of the phlogiston theory began with the work of 

 Joseph Priestley, preacher and scientist, who succeeded in isolating 

 and identifying oxygen. 



Before even Priestley, however, was Cavendish, shy, eccentric 

 misanthrope, who played with chemical apparatus and weighed the 

 earth, in preference to spending his wealth, and who won immortality 

 as the first experimenter to reduce water to hydrogen and oxygen. 

 But it was Lavoisier, later snatched from his laboratory by the French 

 police to die under the guillotine, who molded chemistry into a science. 

 The brilliant Frenchman, science's greatest loss to the Reign of 

 Terror, formulated what is now known as the "law of the conservation 

 of matter." This fundamental law states that in every chemical 

 reaction the weight of the products is exactly equal to the weight of 

 the substances which entered the reaction. Lavoisier also made a 

 list of 33 chemical elements, explained the chemistry of fire and 

 infused into the body of science a new spirit for accurate and patient 

 measurement. 



