208 
THE BORDERLAND OF CHEMISTRY AND ELECTRICITY. 
mysterious or secret you may be perfectly certain is not true. The 
alchemists devoted their energies to the discovery of the philosopher's 
stone. 
Aristotle developed a doctrine of the four elements—earth, 
water, air or steam, and fire; earth meant dryness and coldness; water— 
coldness and wetness; air or steam—wetness and heat; fire—dryness 
and heat. He supposed matter to be of one kind, the difference of 
material he supposed to be dne to the greater or less amount of the 
four conditions which were supposed to be necessary to all substances. 
It had nothing to do with what we now know as chemical composition. 
Pliny believed in the formation of water from air, which he deduced 
from the fact of the formation from the disappearance of clouds. He 
thought rock crystal was produced from moisture, being, in fact a kind 
of ice. The question of the change of the base into the noble metals 
was considered to be an open question. The Byzantine philosophers 
of the fourth century first used the word “ Chemia " as the name of 
the process which was used for the creation of gold and silver. 
Plutarch mentions that the old name for Egypt was “ Chemia," 
which was given to it on account of the black colour of its soil. The 
same word means the black of the eye, and also dark and mysterious. 
Aristotle's philosophy extended to the Arabs, who in 1640 overran 
Egypt and northern Africa into Spain. Their alchemic education was 
undoubtedly obtained in Egypt, and by prefixing the Arabic article 
to “ Chemia," they arrived at the word “ Alchemy." A celebrated 
Arab named Geber undoubtedly wrote the oldest books known con¬ 
nected with this science, and they have been handed down through 
Latin translations. He actually describes chemical operations, filtration, 
distillation, crystallisation and sublimation, with which actions he pre¬ 
pared new substances, and purified the originals. He used alum, green 
vitrol, saltpetre and sal ammoniac. He manufactuerd nitric acid or 
aqua fortis , and from it the solvent of gold known as aqua regia , which 
is a mixture of nitric and hydrochloric acids. If he prepared nitric 
acid then he undoubtedly knew what sulphuric acid was. He also had 
knowledge of mercuric oxide and corrosive sublimate. Unfortunately 
he thought that the differences between metals were due to changing 
quantities of mercury and sulphur, of which he supposed all metals 
were composed. 
Under Arab teachers the Spanish schools were thronged with 
students from all parts of the so-called Christian world. In Spain 
lived Raymund Lully, in Prance, Arnold Villanovanus, in Germany, 
Albertus Magnus. Roger Bacon (thirteenth century) was an alchemist, 
and he was tried for sorcery at Oxford. He thereupon wrote 
a celebrated book in which he described so-called supernatural 
appearances as being due to natural causes. His defence was so con¬ 
vincing that he was acquitted. It is a pity that in these days vendors 
of quack medicines cannot be brought before courts of law, as I very 
much doubt whether they would be acquitted of nefarious practices 
and deceit. 
