JAPAN CAMPHOR.

It has been commonly supposed that the people of China or Japan prepare a factitious substance resembling native camphor, and impregnated with its virtues by the admixture of a small quantity of the genuine, which is sold to the Dutch factory for thirty or forty dollars the pekul, sent to Holland, and afterwards refined to the state in which we see it in our shops, where it is sold at eight to twelve shillings the pound.  It appears however an extraordinary circumstance that any article could possibly be so adulterated, bearing at the same time the likeness and retaining the sensible qualities of its original, as that the dealers should be enabled, with profit to themselves to resell it for the fiftieth part of the price they gave.  But, upon inquiry of an ingenious person long resident in China, I learned that the Japan camphor is by no means a factitious substance, but the genuine produce of a tree growing in abundance in the latter country, different in every character from that of Sumatra or Borneo, and well known to our botanists by the name of Laurus camphora, L. He further informed me that the Chinese never mix the Sumatran camphor with that from Japan, but purchase the former for their own use, at the before-mentioned extravagant price, from an idea of its efficacy, probably superstitious, and export the latter as a drug not held in any particular estimation.  Thus we buy the leaves of their tea-plant at a high rate and neglect herbs, the natives of our own soil, possessing perhaps equal virtues.  It is known also that the Japan camphor, termed factitious, will evaporate till it wholly disappears, and at all stages of its diminution retain its full proportion of strength; which does not seem the property of an adulterated or compounded body.  Kaempfer informs us that it is prepared from a decoction of the wood and roots of the tree cut into small pieces; and the form of the lumps in which it is brought to us shows that it has undergone a process.  The Sumatran sort, though doubtless from its extreme volatility it must be subject to decrease, does not lose any very sensible quantity from being kept, as I find from the experience of many years that it has been in my possession.  It probably may not be very easy to ascertain its superiority over the other in the materia medica, not being brought for sale to this country, nor generally administered; but from a medical person who practised at Bencoolen I learned that the usual dose he gave was from half a grain to one or two grains at the most.  The oil, although hitherto of little importance as an article of commerce, is a valuable domestic medicine, and much used by the natives as well as Europeans in cases of strains, swellings, and rheumatic pains; its particles, from their extreme subtlety, readily entering the pores.  It undergoes no preparation, and is used in the state in which, upon incision, it has distilled from the tree.  The kayu putih (Melaleuca leucadendron)