The following are the extracts, promised above, from Dr. Christison’s paper, and which
though copious, afford but a very imperfect idea of the mass of infatuation 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 in-
fenor, 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 in- ■
ferior 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 state Jhis 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. — , „
<« _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.nnaccreted 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
Gam bone-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 after 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
Pam This variety of Gamboge is familiarly known to he 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 pam 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, underjhe name ot
Morison’s Pills, have been satisfactorily traced to an over-dose of Gamboge.”
* Martin’s History of the British Colonies, i. 224 table.
“ The best solvent for separating the r*»sin of Pipe gamboge is sulphuric ether. When
agitated with the powder, a lively orange-red solution is obtained, which becomes Gamboge-
yellow by dilution, and continues to show this tint when very greatly diluted, proving the exceeding
intensity of the colour. On distilling off the greater part of the ether, and then driving
away what remains by heating-the residue in an open porcelain cup, a very beautiful, brittle
resin is obtained, which has in thin layers a deep orange-colour and complete transparency, and
in thicker masses a cherry-red tint, so dark as to produce almost complete opacity, and which
possesses in fine powder a lively Gamboge-yello.w hue.* It is remarkable that the very volatile
fluid, sulphuric ether, adheres, .with great force to this resin, insomuch as to be the source of
much trouble, and even error in a quantitative analysis. The vapour-bath heat of 212° F. 1
found insufficient to drive off so much ether as to leave the resin firm when cold ; even at the
temperature of 270°, maintained by means of a muriate of lime-bath for six hours, so large a
quantity was retained, that the detached principles almost always weighed conjunctly three per
cent, more than the crude subject of analysis ; nay, a heat of 400° subsequently applied for
four hours by an oil-bath, which I considered the highest temperature to be safely applied to the
resin, and which sent off copious bubbles of ethereal vapour, still left a slight surplus of weight
in the separated principles when summed up.
The ether leaves, in the case of Pipe gamboge, a flocculent matter, which, when
thoroughly- exhausted by the repeated action of the same fluid, coheres somewhat and acquires
a very pale yellowish white colour.' In fine specimens of this Gamboge I have always found
the flocculent residuum to be composed entirely of gum, presenting the leading characters of
the prototype of the gummy principle named Arabin, from .its forming almost the entire mass
of gum arabic. It is entirely and easily soluble in cold water, forming a pale yellowish solution,
which, when concentrated, becomes viscous, and wheri dried forms a transparent, reddish
substance, of a mucilaginous taste without acridity. Braconnot thought the gum analogous to
that of the plum-tree*; which, however, contains a considerable proportion of the insoluble
variety of gum named Cerasin, a variety entirely absent in Pipe gamboge.
The proportions of the two principles vary somewhat, as will appear from the following results
of trials made with one hundred grains of two distinct specimens apparently of the same
quality.
First. Second.
Resin heated at 400°, till it ceased to lose weight......................... .......................... 74.2 71.6
Arabin, or soluble gum, heated at 212°, till it ceased to lose weight . . . , . . . . . . 21.8 24.0
Moisture discharged by a heat of 2 7 0 ° .... . . . . . . . . . . . . . . . . . . . . . . . . 4.8 4.8
Woody fibre........................................................... ...................... .............. trace, trace.
Total___ 100.8 100.4
In another analysis so much as 27.3 per cent, of gum was obtained. But as the resin was
not carefully determined, and there was therefore no check on the analysis, the accuracy of that
result cannot be .positively relied on.
It follows that Pipe gamboge consists of resin and gum, without any volatile oil, which is
a very common ingredient of other gummy resinous exudations. The large proportion of gum
accounts well for its easy miscibility with water, by which, on the one hand, its suitableness for
the purposes of the painter is judged of, and which, on the other hand, renders it in medical
practice convertible into a smooth and perfect emulsion, without any of the additions usually
resorted to for that end.”
“ 2.—Passing next to the lump or cake gamboge, it must appear evident, that the
composition of this variety will vary much according to its quality,* * *” The chemical
composition of Cake gamboge is also materially different. It is not, like the Pipe
variety, entirely dissolved by the successive action of the two solvents, sulphuric ether
and cold water. About eleven per cent, of insoluble matter remains, which in cold water subsides
commonly in two layers, the uppermost white, and very finely pulverulent, the lower one
greyish, and rather flocculent. The former proved to be fecula, entirely soluble in boiling
water, and then giving an abundant blue precipitate with tincture of iodine—the latter quite
insoluble in boiling water, with even six hours of ebullition, burning entirely away, with the
* Its colour is so intense that it communicates an appreciable yellowness to ten thousand times its weight of spirit.