The following are the extracts, promised above, from Dr. Christison's paper, and which though copious, afford hut a very imperfect idea of the mass of information embodied in this lucid and scientific memoir.
"The source of Gamboge has long been a subject, of doubt and controversy among Pharmacologists and medical Botanists ; nor are the opinions and information, even of the most recent authors, by any means satisfactory. In order to understand this enquiry thoroughly, it is necessary to be in the first instance distinctly aware, what are the articles to which the name of Gamboge is usually given, and whence they are obtained.
In point of fact, a considerable number of kinds of Gamboge, differing more or less from one another in quality, and even in nature, as well as in their place of origin, are known in commerce. The most important and finest qualities are generally considered to come from the kingdom of Siam, and are imported into England from China by way of Singapore. Among these the wholesale druggist distinguishes by name at least two, and generally three varieties — pipe gamboge, cake or lump gamboge, and coarse gamboge. Pipe gamboge, which is invariably the finest, has sold in the London market during the last eight years, at prices varying from two shillings and ten-pence to five shillings a pound, exclusive of duty.* Cake or lump gamboge is sometimes very nearly equal in quality to the last, but is more commonly somewhat inferior, and therefore sells for at least three-pence a pound less. The two qualities are sometimes mixed in the same packages ; sometimes each package contains but one ; and frequently, on the other hand, the cases contain not merely pipe and cake gamboge, but likewise more or less of a very inferior sort, by the presence of which the price is materially affected. This inferior sort again, of which there are probably many varieties confounded together in the rude nomenclature of the English drug-market under the name of coarse gamboge, and which will be seen presently to be nothing else than a cake gamboge of low quality, often constitutes the entire contents of the package. In its crude slate this is quite unfit for the purposes of the painter, and is equally rejected for medicinal use ; and consequently it bears so contemptible a character in the market, as to bring scarcely ten-pence a pound, when the other sorts are worth three or four times as much. For this statement I am indebted to Mr. Stead, an extensive and experienced wholesale druggist in London."
" 1. — Pipe gamboge is so termed in the nomenclature of the drug-market, from its peculiar form. It occurs chiefly in cylindrical masses, from three quarters of an inch to nearly three inches in diameter, commonly hollow, and often doubled upon themselves, and cohering. Not unfrequently several of these pipes or cylinders are firmly accreted into irregularly-shaped cakes or balls, two or three pounds in weight; in which, however, the remains of the cavities may be traced, though much flattened. The surface of the unaccreted cylinders is dirty greenish yellow, and striated, evidently from the impression of the reed moulds into which it is run when soft. Where several cylinders have been joined together, and squeezed into a cake or ball, the mass is usually wrapped in large leaves, which appear to belong to a malvaceous or bombaceous plant. Pipe gamboge is very brittle, and presents a somewhat conchoidal fracture, the surface of which is smooth, brownish yellow in tint, and glimmering in lustre. It becomes bright Gamboge-yellow wherever it is frayed or rubbed, and very readily forms an emulsion, or paste of the same hue, when rubbed with the wet finger. It has scarcely any taste ; but alter a short time produces a sensation of acridity, especially in the back of the throat. Neither has it any smell; yet the fine dust, raised in pulverizing it, quickly irritates the nostrils, even in quantities inconceivably minute, exciting a profuse flow of mucous, and some sneezing, but without pain.
This variety of Gamboge is familiarly known to be an excellent and powerful purgative, which in the dose of three, five, and, seldom more than seven grains, produces profuse watery discharges ; nor has there ever appeared to me any reason for dreading its effects, as our predecessors did ; for its action is seldom or never accompanied with much pain or other uneasiness, if it is thoroughly pulverized with some other finely pulverizable substance, such as cream of tartar. Yet on the other hand, it is a dangerous poison in large doses ; one drachm has proved fatal ; and the cause of death is violent inflammation of the bowels. I believe that the occasionally fatal effects of a nostrum much in vogue in the present day, under the name of Morison's Pills, have been satisfactorily traced to an over dose of Gamboge."
- Martin's History of the British Colonics, i. 224. table.
