Improvement in lamp-lighting during the nineteenth century has consisted of an indefinite number of inventions, all aiming at economy, brilliancy, steadiness, convenience, beauty, and so on. But in no respect has this improvement been more rapid and radical than in the adaptation of lamps to the various combustible fluids that have bid for favor. While the various oils, animal and vegetable, were almost solely in vogue as illuminants at the beginning of the century, they were largely superseded at a later period by the burning-fluid known as camphene. This was a purified oil of turpentine, which found great favor on account of its economy, convenience, cleanliness, and brilliancy of light. But it was very volatile, and its vapors formed with air a dangerously explosive mixture. Yet with all this it might have held its own for a long time, had not Gesner, in 1846, discovered that a superior mineral oil, which he called “kerosene,” could be readily and profitably distilled from the coal found on Prince Edward Island. This kerosene or hydrocarbon oil speedily displaced camphene as an illuminant. Its manufacture rapidly developed into an important industry in the United States, and large distilling establishments arose, both on the Atlantic coast, where foreign coal was used, and throughout the country, wherever cannel or other convertible coal was found. With the discovery of petroleum in paying quantities on Oil Creek, Pa., in 1859, there came about a great change in kerosene lamp-lighting. It was found, upon analysis, that crude petroleum contained about fifty-five per cent of kerosene, which constituted its most important product. The manufactories of kerosene from cannel or other coal, therefore, went out of existence, and new ones, larger in size and greater in number, sprung up for the manufacture of kerosene or, popularly speaking, coal oil, from petroleum. This illuminant came into almost universal favor for lamp use, owing to its cheapness and brilliancy. It is not free from danger when improperly distilled, but under the operation of stringent laws governing its preparation and testing, danger from its use has been reduced to a minimum. In rural districts, in smaller towns and villages, wherever economy and convenience are essentials, and when beauty in lamp effects is desirable, the kerosene illuminant has become indispensable.