Even a superficial examination of the chemical composition of oil, a hydrocarbon, in which the carbon, in a proportion of 80 to 88 per cent., is combined with hydrogen, and sometimes with a little oxygen, reveals in this compound a marvellous source of thermal energy, which may manifest itself in various ways. For, from the greenish-brown oil which is lighter than water, no less than 128 chemical compounds are obtained, which are used in forty different industries. From the retort in which the crude oil is distilled comes an infinity of substances of basic importance in modern industry.
Although the intensive use of oil and its industrial applications are of comparatively recent date, the discovery of deposits of petroleum goes back to remote antiquity.
The history of oil is as old as the world, since there is already mention of it in the Book of Genesis. The wells of Baku were known long before the Christian era. In the peninsula of Apsheron, where they are situated, arose the cult of Zoroaster and the fire-worshippers. According to the latter, the flames which escaped from the soil would burn until the end of the world. They were, at any rate, famed throughout the world nearly three thousand years ago.
The Greeks and Romans were acquainted with oil. The latter called it _bitumen_. In Low Latin it was _petroleus_, from _petra_--stone, and _oleum_--oil; and the word has come down to us through the scholars of the seventeenth and eighteenth centuries who adopted it.
In ancient mythology and literature oil is often mentioned. It is probably with oil that the Centaur--to avenge himself upon Hercules--was obliged to anoint the famous shirt of Nessus! "It is not without reason," says Plutarch, "that certain authors, wishing to restore truth to legend, assert that petroleum is the substance which Medea used to smear the crown and veil that play so great a part in the tragedies; for fire does not issue from them of itself, but when they are brought near a flame fire is communicated to them by some kind of attraction with such rapidity that the eye can scarcely follow it."
Herodotus, in his works, mentions the oil-fields of Zante; Pliny those of Agrigente in Sicily; Plutarch those of Ecbatana and Babylon. "The land of Babylon," he says, "is impregnated with fire.... It is as though the soil, agitated by the fiery substances which lie concealed in its bosom, has a sort of pulse which makes it quake." When Alexander conquered these regions he was particularly astonished, in the province of Ecbatana, at "a gulf from which rivers of flame streamed continually, as though from an inexhaustible source."[5] His return to Babylon was celebrated by the burning of two parallel streams flowing through the streets. And one of his courtiers, to amuse him, caused a young man to be anointed with oil; scarcely had it touched his body when he was enveloped in flames.