Let us, therefore, take first the word “petroleum” as we know it to-day. It covers a multitude of products derived from the refining of crude oil, though the word does not suggest any of them. It is quite a generic term, and in a general way represents the whole of that ever-increasing family of hydrocarbons--the refined products of crude oil. There is no doubt that it derives its name from the Latin _petra oleum_, which, literally, is rock oil, and equivalents of the name are found in all languages. Even in modern practice we use the word, though not in a specific sense, while our own Government usually refers to “petroleum oil,” which, of course, involves tautology. Crude petroleum is known throughout the oil-fields of the world as denoting the crude oil coming from the wells: then we have petroleum spirit, otherwise the lightest form of refined oil; we have petroleum distillate, designating an illuminating oil; but, “petroleum oil” is, it is to be regretted, generally used as suggesting some form of petroleum product. Though the petroleum industry--in its commercial sense--only goes back some sixty years, the use of petroleum can be traced to Biblical times, for was it not the great Prophet Elisha who told the widow to “Go, sell the oil and pay thy debts and live”? Job also speaks of the rock which poured him out rivers of oil; in Maccabees we find that the priests hid the fire which they took from the altar in a deep pit without water; while Nehemiah called the liquid which burst into flame and kindled a great fire by the name “Nephthar, which is as much as to say, a cleansing; but many call it Nephai.” And so, in many parts of the Old as well as in the New Testament, oil is clearly referred to, and, in Biblical times, as much later, was looked upon as a sacred fire. Many ancient authors make extensive reference to oil, prominent among them being Herodotus, who described the methods adopted at the pits of Kirab for the raising of the oil, which liquid “gives off a very strong odour.” Petroleum, as known in Biblical times, and as so widely known to-day, occurs in greater or less quantity throughout the world, and it is found in the whole range of strata of the earth’s crust, from the Laurentian rocks to the most recent members of the Quaternary period, though it is found in commercial quantities almost wholly in the comparatively old Devonian and Carboniferous formations on the one hand or in the various divisions of the comparatively young Tertiary rocks on the other.