Paraffine (Lat. parum affinis, of weak affinity), a white, waxy substance, which was discovered in 1830 by Reichenbach among the products of the distillation of wood. It has since been produced by the distillation of many organic substances, such as resins, bituminous shales, peat, and boghead coal, and has been found ready formed in some varieties of petroleum, in the mineral ozokerite, in bitumen, and in earth wax. That paraffine existed in petroleum was noticed by Buckner in Bavarian oil as early as 1820; but as he did not pursue the inquiry to practical results, the credit of the discovery is assigned to Reichenbach, who ten years later fully described its properties and gave it its name. It was found in Rangoon petroleum in 1831, by Christison of Edinburgh, who had no knowledge of Reichen-bach's discovery, and was named by him petro-line. American petroleum contains very little, but the Rangoon and Java oil affords from 10 to 40 per cent. - Various methods are employed for the preparation of paraffine, depending upon whether it is a direct or an incidental product. Crude petroleum is distilled until 25 per cent, has gone over; the remaining portion is caught in tanks surrounded by ice or refrigerating mixtures, and the paraffine cake condensed by the cold.
Enormous quantities of paraffine are made from ozokerite, which is a yellow vegetable wax, of fibrous structure and light specific gravity, found in Austria, Moldavia, the Caucasus, and near the Caspian sea. In its natural state it will melt readily, but it requires to be wrapped around a wick before it will burn. In the manufacture, 300 lbs. of ozokerite are subjected at a time to fractional distillation in an iron still, provided with coolers and condensers; the yield is 8 per cent, of oil and 60 per cent, of paraffine. The oil is reserved for illuminating purposes. A portion of the light oil, which boils below 212° F., is used* in refining paraffine. The crude paraffine contains an oil which is removed under a hydraulic press and distilled to save adhering paraffine and for other purposes. The press cakes are melted and treated with sulphuric acid; the acid is neutralized with lime, and the paraffine distilled off. The product is again pressed, melted with the light oil mentioned above, and once more pressed. The final result is a perfectly white, transparent, hard substance, ready for the manufacture of candles.
The manufacture of paraffine by the dry distillation of peat and boghead coal is divided into two operations: 1, the production of tar; 2, the working up of the tar for illuminating oil and paraffine. Before the discovery of petroleum in Pennsylvania, this industry was regarded as one of great importance. The illuminating oil was called kerosene, a trade name which has since been applied to refined petroleum. After the introduction of petroleum this industry declined in the United States, but in Scotland it is still extensively practised under the patent of Mr. Young. (See Kerosene.) - Pure paraffine is a white, inodorous, tasteless substance, resembling spermaceti, harder than tallow, softer than wax, and having a specific gravity of 0'877. Its melting point depends somewhat on its origin, and ranges from 109° to 149° F. An ultimate analysis yields carbon 85 and hydrogen 15 per cent. It is insoluble in water, but readily soluble in warm alcohol, ether, oil of turpentine, olive oil, benzole, chloroform, and carbon disulphide. It is indifferent to the most powerful acids and alkalies, and can be distilled unchanged with strong oil of vitriol. It readily combines in all proportions with wax, stearine, palmitine, and resin.
When required for candles, its melting point is raised by fusing it with stearine, wax, or spermaceti. - Besides the consumption of paraffine in the manufacture of candles, its application in the arts is extensive. Meat several times immersed in a bath of melted paraffine will keep for a long time; and when wanted it is only necessary to melt off the adhering film to prepare it for cooking. Further uses of paraffine are for stoppers to acid bottles, to coat paper for photographic uses, as a lubricator, as burning oil, to coat pills, to refine alcohol and spirits, for the preservation of timber, to preserve fruit, for oil baths of constant temperature, to prevent the oxidation of metals, to render fabrics water-proof, in the manufacture of matches, as a disinfecting agent, and as a varnish for leather. It is introduced into the sugar vacuum pans to prevent the frothing of the sirup. In some forms of the galvanic battery paraffine is introduced to prevent the evaporation of the liquid, and paraffine insulators are employed on telegraph lines. If paraffine be heated with sulphur, it is decomposed, and sulphuretted hydrogen is evolved. This reaction is now employed in the preparation of sulphuretted hydrogen gas for laboratory use.
Heated for about 60 hours with nitro -sulphuric acid, paraffine yields a liquid called paraffinic acid, which has the specific gravity of 1.14, is insoluble in water, soluble in ether and alcohol, combines with alkalies, and burns with an illuminating flame. Chlorine gas decomposes paraffine, yielding hydrochloric acid. In medicine the preservative and protecting properties of paraffine are brought into frequent requisition; and in general, its chemically indifferent properties and permanent character render it one of the most useful products of industry.