The history of chemistry

Primitive man found out by trial and error how to carry out a certain number of simple chemical changes, but under the ancient Egyptian civilization men learned how to work copper, tin, iron and precious metals; knew how to make pottery, glass, soap and colouring agents, and how to bleach and dye textile fabrics. These arts were the beginnings of the chemical industries of today.

The early scientific study of chemistry, known as alchemy, grew up in the first few centuries A.D. at Alexandria in Egypt. There two important things came together: one was the practical knowledge of the Egyptian workers in metals, pottery and dyes; the other was the learning of the earlier Greek philosophers, such as Hippocrates and Aristotle. At the same time alchemy was much influenced by ideas from the East about magic and astrology-foretelling the future from the stars.

Greek philosophers regarded debate about the nature of matter as superior to experiment, and some held that all matter was made up of the same four ‘elements’-earth, fire, air and water. Many people therefore thought that if these elements could be rearranged, one substance could be changed into another. For instance, a base metal could perhaps be turned into gold. The chief aim of the alchemists was to find a way of doing this.

Alchemy came under Arab influence when the armies of Islarm conquered Egypt during the seventh century. The Arabs carried its study into Western Europe when they advanced into Spain. Many Arabic words are still used in chemistry-‘alkali’, ‘alcohol’ and even ‘alchemy’ itself, which means ‘the art of Egypt’. The greatest Arab alchemist was Jabir ibn Hayyan, possibly the same person as Geber, author of two important books on alchemy known from the Latin translations of the thirtennth century. Jabir claimed that mercury and sulphur were ‘elements’ like the four Greek ones. He said that all metals were composed of mercury and sulphur in different proportions. To change a base metal into gold required the proportions to be changed by the action of a mysterious substance which came to be called ‘the philosopher’s stone’. Alchemists searched in vain for this substance for several hundred years.

Alchemy was studied widely in Europe during the twelfth and following centuries, and attracted the attention of many learned men. Though they were doomed to fail in their attempts to make gold, their work led to the growth of a great deal of new chemical knowledge and of methods of making experiments. Many of the later European alchemists, however, were complete frauds who preved upon trusting people by all sorts of tricks, and the subject fell into disrepute. By the first half of the sixteenth century, the aim of the alchemists had changed from the making of gold to the making of medicines. In particular they sought a fanciful substance called ‘the elixir of life’, a powerful medicine which was to cure all ills, and which some people thought would turn out to be the same substance as ‘the philosopher’s stone’. This phase of chemistry lasted till about 1700.