We are not wholly indebted to the animal kingdom for a supply of the material for candles, several vegetable oleaginous substances having been recently introduced as valuable substitutes. On the 2d of November, 1829, a patent was granted to Mr. John Soames, jun. of Spitalfields, for the right of separating the constituent principles of the cocoa-nut oil of commerce, which, from its consistence at ordinary temperature, is also called " butter of cacao." Before the date of this patent, cocoa-nut oil was of very limited utility, owing to the presumed necessity of artificial heat to render the mass sufficiently fluid to be burned in lamps, and to that apparent want of solidity which is required in the manufacture of candles. Mr..Soames's process for separating the fluid from the solid matter in cocoa-nut oil is as follows: - the oil is put into strong linen bags, 2 feet long, 6 inches wide, and 11/2 inch thick; these are covered with stout sack-cloths made for the purpose, and are laid flat upon the horizontal bed of a hydrostatic press, leaving a small vacant space between the bags. Pressure is then given to them, and continued until the oil ceases to flow, or is only given out by drops slowly.
This oil being received into a cistern, is allowed to stand a little time to deposit its impurities, after which it is drawn off clear, and preserved for burning in lamps, etc. The solid portion being now taken out of the bags in the press, is next to be purified from the other vegetable principles with which it is usually combined, such as fibre, mucilage, etc. For this purpose it is put into a covered boiler of tinned copper, which is immersed in a water-bath to prevent the liability of an excess of heat; there is then added to it two parts, (or two per cent.) by weight, of sulphuric acid, of spec. grav. 1.8, diluted with six parts of water. Boiling then coagulates and precipitates the foreign matters, which may be separated by skimming, straining, or filtering, while warm in the fluid state, and by allowing them to settle in the cold state. The substance thus obtained is of firm consistence, and forms a valuable material in the making of candles that are now extensively used. In the Quarterly Journal of Science, an interesting account is given of the piney tallow tree of India, which we introduce in this work, as the writer observes, that "it may be imported into this country at less than one-fourth the price of wax; and that although it does not possess all the advantages of that substance, it is considerably superior to animal tallow." This substance, he says, "is a concrete inflammable, partaking of the nature of wax and oil, which, from its appearance, may not inaptly be termed a tallow.
It is in use only in the town of Mangalore (province of Canara), and is there employed medicinally as an external application for bruises and rheumatic pains; and likewise, when melted with the resin of the same tree, is used as a substitute for tar in paying the bottoms of boats. The method of preparing this material is simply to boil the fruit in water, when the tallow is soon found to rise to the surface in a melting state, and on cooling forms a solid cake. Thus obtained, the piney tallow (piney is the native name of the tree which produces it) is generally white, sometimes yellow, greasy to the touch, with some degree of waxiness, almost tasteless, and has a rather agreeable odour, somewhat resembling common cerate. It melts at a temperature of 971/2°, and consequently remains solid in the climate of India, in which respect it differs from palm or cocoa-nut oil: wrapped up in folds of blotting paper, and submitted to strong pressure, scarcely sufficient oil, or elain, as it is termed by M. Bracconot, is expressed to imbue the inmost fold.
Its tenacity and solidity are such, that when cast in a rounded form of nine pounds' weight, the force of two strong men was not sufficient to cut it asunder with a fine iron wire, and even with a saw there was considerable difficulty in effecting a division. When manufactured into candles, it comes with facility from the moulds, thus differing from wax, which does not readily admit of being cast; it gives as bright a light as tallow, and has the advantage of that material in being free from unpleasant smell, and in not emitting a disagreeable odour when extinguished. It unites, in all proportions, with wax, spermaceti, and tallow; and forms compounds with the two former, intermediate in their melting points.
according to the proportion in their ingredients, and better adapted to the purpose of making candles than the pure and more fusible substance itself." With the view of ascertaining the comparative combustibility of piney tallow candles of the materials undermentioned were cast; one mould was used for all, and the wicks were composed of an equal number of threads. Having been accurately weighed, they were burned for one hour in an apartment in which the air was unagitated, and at a temperature of 55°.
Weight in grains when lighted.
Weight at the end of one hoar.
Half wax, half piney tallow
Half sperm, half piney tallow
Animal tallow ....
Half tallow, half piney tallow
In the year 1830, a solid substance, resembling wax in most of its properties, was obtained by M. Manicler, a French chemist (lately deceased), from palm oil, an English patent for which was taken out in conjunction with Mr. James Collier. The specification states that the process consists in placing the palm oil, or butter of palm, in a metallic vessel or boiler, made of tinned iron, and provided with a close cover and safety valve, upon the principle of Papin's Digester; water, in the proportion of about one-sixth part to the substance being added. The vessel being well closed, it is submitted to the action of fire, so as to raise the steam to a pressure of two or three atmospheres, which operation is to be continued for two hours. After the material has been thus prepared, it is to be put into wrappers of linen or woven horse hair, or both may be used, and submitted to powerful pressure: by this means the elain, or fluid oil, is separated, and the stearin remains in the wrappers in a solid state.