By Edward Salmon.
AS has become so universal an agent of illumination, and enters so considerably into the domestic economy of the world to-day, that it is somewhat surprising to remember the present year is the centenary of the discovery of the practicability of utilizing it for all sorts of purposes, from the lighting of the highway and the home, to the cooking of the dinner on a day when it is convenient to do without a coal fire.
Natural gas, which was spoken of as "spirit," and was more or less of a mystery, had been known for centuries, and is even said to have been used in China as an illuminant long before it was turned to account in Europe. In many places natural gas forced itself up through fissures in the earth, became ignited and burned incessantly, to the terror, no doubt, of some good people, who thought the flame came from Hades itself.
Some time towards the end of the seventeenth century a well in the neighbourhood of Warrington was found to contain inflammable air, and it is believed that the result of the application of a lighted candle to the mouth of this well suggested to the Rev. Dr. John Clayton the idea of making experiments in coal distillation, that is, in the heating of coal until the gas is forced out of it. He placed some coal in an iron or brick receptacle called a retort, with an aperture through which the gas escaped when distillation, or carbonization, commenced. Dr. Clayton describes how at first there came steam, then a black oil, and then a spirit, the last of course being gas. He had no notion what do with it, and was surprised to find that as it issued from the retort it caught fire on a light being applied to it. He filled some bladders with it, and when he wished to divert his friends, pricked a hole in one of these bladders, pressed the sides slightly and lighted the gas. Infinite amusement is said to have been derived from watching the "spirit" gradually burn itself out.
It is strange that, though Dr. Clayton thus came about the year 1690 so near to it, the discovery of gas in the form in which we know it to-day was not made for another century—till 1792, when William Murdoch, an engineer in Redruth, Cornwall, conceived the idea.
Certain impurities in the gas as it leaves the retort were the stumbling-block to progress. After some experimenting, Murdoch succeeded in removing them sufficiently to enable him to startle the Redruthians by lighting his own premises with gas before the close of 1792. Murdoch was one of the world's truly great men, and an excellent
