Camphor is found in every part of the trees; in the interstices of the perpendicular fibres, and in veins of the wood; in the crevices and knots, in the pith, and in the roots. The modes by which it is extracted differ in different countries. In Borneo and Sumatra, the largest pieces are picked out with sharp instruments; and the smaller ones are procured by rasps, to which, along with bits of wood and other impurities, they adhere. The Chinese cut off the branches, chop them very small, and place them in spring water for some days. They then put them into a kettle, and boil them for a certain time, during which they keep constantly stirring them with a stick. As soon as the camphor, in a white and frosted appearance, is observed to adhere to the stick, the whole is strained. The liquor is subsequently poured into a basin, and, after some hours, the camphor coagulates into a solid mass. In Japan it is usual to obtain camphor by cutting the roots and extremities of the branches into chips, and exposing them to the steam of water in close vessels. In other countries the roots, wood, and leaves, are all boiled in large iron pots, having a kind of tubular apparatus, which is stuffed with straw, and leads to certain large vessels called receivers. In this operation most of the camphor becomes condensed in a solid form amongst the straw; and the remainder passes with the water into the receiver. In a crude state camphor is formed into irregular lumps of yellowish grey colour, somewhat resembling nitre, or saltpetre. It is imported into Europe in canisters; and the refining of it was long kept a secret by the Venetians. The Dutch have since performed this work; and large quantities of camphor are now also refined by some of the English chemists. The best camphor is imported from Sumatra. The principal use of this drug is in medicine; and it was formerly in high repute. Dr. Cullen says that it has been employed with advantage in fevers of almost all kinds: but, since the free use of opium has been introduced, camphor has been little employed in this country, though its utility has been fully established by some of the most eminent practitioners of the Continent. It has often been found to relieve tooth-ache and rheumatism. Several preparations of camphor, in combination with other substances, are used in medicine, of which, perhaps, the most common is that with spirit of wine. To insects the effluvium of camphor is so disagreeable that they quickly avoid it. Hence it is customary to place pieces of it in collections of natural history, to prevent their destruction by these voracious little creatures. For carpenters' work the _wood_ of the camphor tree is much in request. It is light and durable; and, in consequence of long retaining its aromatic smell, is not liable to be injured by insects.