Tho use of alcohol for lighting purposes dates from the earlier part of the nineteenth century. Its non-luminous flame was rendered luminous by an admixture of terpenes or other hydrocarbons. Turpentine was chiefly employed for the purpose, but camphor, coal-tar naphtha, and shale oil were also used. The product was variously known as camphene or camphine, gasogene, 'camphorated gas," and ' burning fluid "; and previously to the introduction of petroleum for lighting purposes, about the year 1860, large quantities of alcohol were employed in making these illuminating mixtures.

The names "camphene" and "camphine" were also applied to rectified turpentine, which itself was used for burning. Turpentine oil alone, however, burns with a flame which, though luminous, is very smoky. When mixed with about four parts of alcohol, turpentine gives a flame which is still luminous, whilst the smokiness is much diminished. According to R. F. Herrick1 such a mixture was introduced by Webb into the United States in the year 1833, but the weakness of the only alcohol obtainable by him caused some difficulties with the product. Illuminants of like character were also being produced in Great Britain and France at about the same time, or a little earlier. A patent granted to Ludersdorf of Berlin in the year 1834 describes a mixture made with 95 per cent. alcohol, of which four volumes were used with one volume of rectified spirits of turpentine. The fluid was burned in a lamp provided with a wick, and the lamp was lighted by igniting a little alcohol placed in a cup surrounding the wick tube.

Later on, the invention of the Auer incandescent mantle for gas flames afforded another means of obtaining light from alcohol, thus dispensing with the necessity of enriching the spirit with hydrocarbons. A number of lamps have been devised for the convenient application of this principle for use with ordinary denatured alcohol. The spirit is vaporised, and the vapour mixed with air as in the Bunsen burner is ignited under such conditions that the flame impinges upon a superimposed mantle, and raises it to incandescence. Lamps of this character suitable for household use, street lighting, and the illumination of large buildings have been manufactured on the Continent for many years. Questions of price apart, the advantages claimed for alcohol as against petroleum (kerosene) for lighting are that the alcohol lamp is practically odourless and smokeless, radiates less heat, and gives a whiter and more uniform light. In addition, alcohol is safer than kerosene, inasmuch as in case of fire the flame is more readily extinguished by water, which is miscible with alcohol but not with kerosene.

1 " Industrial Alcohol," p. 207.