THE MOLECULAR COMPOSITION OF MATTER 73 



There is some reason to believe that the thinkers of 

 the school which considered the essence material and 

 hence sought for it by experiment either formed or 

 were among the early alchemists. The origin of 

 alchemy and even the derivation of the name itself 

 are, however, matters as to which historians are in 

 doubt. By the fourth century of this era, historical 

 evidence seems to show that the attention of the 

 alchemists had become centered upon the problem of 

 the transformation of baser metals into gold and silver. 

 This they attempted to accomplish by adding or sub- 

 tracting some of the elementary principles mentioned 

 above. Then" experiments thus led to the discovery 

 of some new compounds and also to methods for separat- 

 ing different substances. Alchemy was largely in the 

 hands of the Arabs until the llth century, when it 

 became European. Although it was experimental it 

 was essentially only descriptive. Its theory was also 

 incoherent and mystical. 



Throughout the centuries during which chemistry 

 was a mystical art rather than a science, progress was, 

 of course, made in the processes of industrial chemistry 

 by "cut and try" methods. The metallurgical opera- 

 tions of smelting and refining advanced. The art 

 of healing progressed during this same period and by 

 the 15th century chemical preparations in medicine 

 had become of considerable popular importance. The 

 attention of the alchemists, therefore, turned from 

 their unsuccessful search for gold to a search for new 

 medicines. But medicine was also a science hi its 

 infancy, one of superstitions, mysteries, and untried 

 theories. Thus as late as 1800 Davy, famous to-day 



