204 MODERN SCIENCE READER 



HISTORY OP CHEMISTRY 1 



The history of ancient philosophy records certain theories 

 of matter which have had a directing influence on chemical 

 thought during later centuries. The most important ideas 

 date from the fifth century, B.C. Empedocles (c. 490-30 

 B.C.), who may have derived his views from the ancient 

 philosophers of the East, held that air, water, earth and 

 fire are the four elements unrelated to one another and 

 forming the basis of the universe. Aristotle (384-322 B.C.) 

 added a fifth element, ousia, a purely spiritual substance 

 pervading the infinity of space. During the Middle Ages 

 not a little energy was lost in researches after this "fifth 

 essence" which, by confusion of ideas, came to be regarded 

 as a fifth elementary form of matter. To Aristotle the 

 material elements were not altogether different from one 

 another, but were forms of a primary substance differen- 

 tiated by properties as dry, moist, hot, cold that were 

 not essential to its nature. Hence, later, the alchemist 's 

 attempt to turn metals into one another, crowned by the 

 belief that such transmutations cannot be effected by any 

 known means. The conception of the atom dates from 

 Democritus (c. 460-370 B.C.), who held that all bodies are 

 made up of the atoms of one and the same substance, and 

 that the difference exhibited by the various forms of 

 matter are due entirely to the differences in the size and 

 shape of the atoms. It is hardly necessary to state that if 

 this undeveloped idea of Democritus had not furnished a 

 suggestion that led to the building up of a useful chemical 

 doctrine, it would deserve no mention in the history of 

 science. It is thus clear that the ancients did nothing 

 directly to the building up of a science of chemistry. 

 Indeed, how much chemical , knowledge can we expect to 

 find in an age when a man like Aristotle did not hesitate 



The New International Encyclopaedia, vol. iv, page 566. 

 Copyright 1903, 1904, 1905, 1906, 1909 by Dodd, Mead & Co. 



