(From the Arabic term caphura). Camphor; called also cqf, cafar, ligatura veneris, caphora; capur, alkosor, altefor; camphor. It is a solid concrete, chiefly obtained from the woody part of some trees which are met with in the island of Borneo in the East Indies, and in Japan; it is only from the latter that it is brought into Europe. The Indians have a species, which they distil from the roots of the true cinnamon tree, that they call baros; (see Cinnamo-mom;) and also a species which separates from the phorae oleum on re-distilling it. It sometimes oozej from the bark of the root of the cinnamon tree in the form of oily drops, which insensibly concrete into white grains: these are called caphura baros Indorum. In the state camphor is extracted from the roots of the camphor tree, it is named camphora rudis. The Japanese cut the wood of the roots and branches in small pieces, and boil them with water in an iron pot. The camphor sublimes in a clay head in friable, granulated masses of a yellowish or dark colour, like the coarsest sugar, mixed with straw, etc. The Chinese macerate the branches in water, and then place them in a pot over the fire: the contents arc stirred with a willow rod, on which the camphor concretes. It is obtained chiefly from the laurus camphora Lin. Sp. Plant. Nat. order oleraceae. In smaller quantities it is obtained from several other vegetables. The thyme rosemary, the peppermint, the root of the canella, many of the labiated plants, and the whole tribe of the laurels, afford it.
As first sublimed or distilled from the wood, it is of a brownish colour, and composed of semi-pellucid grains, mixed with some impure matter; in this state it is imported by the Dutch, then called unpurified camphor. It is purified by a second sublimation, but after a manner only known to themselves, except the Venetians, who formerly were the only refiners of it. Bomare discovered in Holland that it was purified by sublimation. ' The last process in the management is so contrived, that the head of the subliming glass is kept warm enough to make the camphor run together into a mass of its own figure, in which form it is brought into the shops. Dr. Lewis says, that it may be purified in sp. vin. rect. by solution, and recovered from the spirit by distillation, the spirit all rising before the camphor; and after this it may be formed into loaves by fusion, with a gentle heat, in a close vessel.
The ancient Greeks do not mention camphor: it was first used in medicine by the Arabians.
Camphor is a vegetable concrete, white, semitrans-parent, brittle, of a shining fracture, and of a crys-t t 2 talline texture, unctuous to the touch, with a fragrant smell, somewhat like that of rosemary, and a bitter, aromatic, pungent taste, accompanied with a sense of coolness on the tongue: it is volatile like essential oils, but without their acrimony; it also differs both from them and from the sebaceous oils, in suffering no sensible alteration from long keeping, in being totally volatile in a warm air, without any change or separation of its parts, and subliming unaltered in the heat of boiling water. It is lighter than water, burns in it without receiving any empyreumatic impressions, nor is it decomposed by any degree of fire to which it can be exposed in close vessels, though readily combustible in the open air. It combines with concentrated vitriolic, nitric, and acetic acids, rectified spirit of wine, oils, resins, balsams, alcohol, and aether. Of resins, balsams, and oils, it considerably diminishes the consistence. It docs not dissolve, except in a very small proportion, and by the assistance of sugar, in water, in the weaker acids, or alkaline liquors. It melts into an oily appearance with a less degree of heat than that of boiling water; laid on a red hot iron it totally evaporates in a bright white flame and copious fumes, which, condensing, form a soot.
As camphor is found in so many different vegetables, it has been generally recognised as a vegetable principle. It contains an acid united with an oil, and the former may be separated by means of nitric acid. In the best camphor some of the essential oil is separated, and the jets of this oil occasion the peculiar motions of the camphor when swimming in water, described by Prevost and Venturi in the Annates de Chimie, vol. xix.
Camphor is known to be good, if, when it is put upon hot bread, it turns moist; if it becomes dry it is adulterated: it should be kept close in a bottle or a bladder, not to prevent it from losing its quality, but to preserve the whole of it from being lost by evaporation.
As camphor is so useful a medicine, it is necessary to examine its effects on the human machine in the clearest point of view. The first question is, whether its power is of a stimulant or sedative nature ? Dr. Cullen seems clearly to have proved the last when taken into the stomach: externally it is certainly stimulant, for when taken into the mouth it has an acrid taste, and, though by its evaporation it excites a sense of cold air, what remains is a feeling of heat in the mouth and fauces. When taken into the stomach it often occasions pain and uneasiness, which Dr. Cullen imputes to the action of the acrimony upon the upper orifice. When applied to any ulcerated part, it perceptibly irritates and inflames. When thrown into the stomach of brute animals, it operates there by its effluvia; for though it has produced considerable effects on the body, neither the bulk nor weight is found sensibly diminished; hence he concludes the operations have been upon the nerves of the stomach, and to be entirely that of a sedative power. The sudden death of many animals occasioned by it, as experimentally proved, show still more evidently its sedative effects on the senso-rium, destroying the mobility of the nervous power, and extinguishing the vital principle. Camphor first operates by inducing stupor and sleep, and the different symptoms of delirium; convulsions soon follow, and are part of the same series of sedative effects. It evidently shows no stimulant power on the sanguiferous system; for the pulse, where it has been observed, has been slower than before its effects took place by ten strokes in a minute. It is in general also softer and fuller, and a gentle diaphoresis is excited on the skin.