Liquid and solid paraffins are obtained from the tarry product of the distillation of peat, brown coal, and Boghead shale; by Young's process, in which Boghead coal is heated in tubes or retorts; a crude oil is first obtained, which, after purification by redistillation, followed by subsequent treatment with sulphuric acid and exposure to the action of caustic soda, is submitted to the process of fractional distillation. The first elevation of temperature drives over the lighter and more volatile portions, which, when purified by another distillation, yield the fluid known as " paraffin naphtha," a product used as a substitute for turpentine and as a solvent for india rubber. At a much higher temperature the burning oil (the paraffin oil of commerce) comes over. It is a perfectly safe lamp-oil. The third product in point of volatility is a comparatively heavy liquid, (machinery oil), and from this, and others which come over at a very high temperature, the fourth commercial product is separated by the action of artificial cold, and is the solid paraffin now so much used in the manufacture of candles.