There are two kinds obtained from the East, one from Sumatra and Borneo, the other from China and Japan It is extracted from the roots, wood, and leaves of the laurus camphora, the roots affording the greatest quantity. It is distilled in large iron pots, to which earthen heads, stuffed with straw, are adapted, and provided with reservoirs. Most of the camphor becomes condensed in the solid form amongst the straw, and part comes over with the water. The refinement of this camphor is performed by sublimation in low flat-bottomed glass vessels placed in a sand bath, and the camphor becomes concrete in a pure state against the upper part, whence it is separated after breaking the glass with a knife. Lewis asserts that no addition is necessary in the purification of camphor, but that the chief point consists in managing the fire, so that the upper part of the vessel may be hot enough to bake the sublimate together in a cake. Chaptal says, that the Dutch mix one ounce of quick lime to every pound of camphor, previous to distillation. Mr. Gray states, that two pounds of quick lime should be added to each hundred weight of rough camphor, and the sublimation be performed in a very gentle heat.
Camphor is likewise obtained from thyme, rosemary, and other vegetable substances.
Purified camphor is a white, concrete, transparent, extremely volatile, and inflammable substance, of a powerful fragrant odour, and acrid taste. It is insoluble in water, but soluble in alcohol, ether, and the essential oils. It is used in the arts for assisting the solution of resins; also in medicine.
An acid obtained by repeated distillation of nitric acid upon camphor. It appears in the form of crystals, soluble in alcohol, oils, and mineral acids. It also dissolves easily in hot water, but requires about 200 parts for its solution at the ordinary temperature.