plant yielding Siam Gamboge has not been ascertained ; for no competent European botanist has seen 
either the tree, or specimens of it. That it is a guttiferous plant cannot be doubted, but the precise species, 
or even genus is still uncertain. It is not impossible that it may be some plant which yields Ceylon Gam- 
boge (Hebradendron cambogioides) ; but at present we are deficient of proofs of this notion, though 
several circumstances favor it. The only account which we possess of the method of obtaining Siam Gam- 
boge, is that given to Konig by a Catholic Priest residing in Cochin China. According to this account, 
when the leaves or branchlets are broken a yellow milky juice issues guttatim (hence the origin of the term 
Gummi Guttce applied to this substance,) and is received either on the leaves of the tree or in cocoa nut 
shells, and from thence is transferred into large flat earthen vessels, where it is allowed to harden during 
the summer season, and is afterwards enveloped by leaves. From another authority we learn that the 
cylindrical form of some of the pieces is owing to the juice being run into the tubular cavities of bamboo 
canes. Resin of Gamboge : Gambogin or Gambogic acid. This resin is brittle, in thin layers, of a deep 
orange colour, in thicker masses, of a cherry red tint. When reduced to this state of fine powder, its 
colour is lively gamboge yellow. “ Its colour is so intense “ says Dr. Christison,” that it communicates an 
appreciable yellowness to ten thousand times its weight of spirit.” A thin film of gamboge emulsion is an 
excellent microscopic object for observing the active molecules, described by Mr. Brown in the Philosophical 
Magazine for September 1828 and 1829. 
Detection of Gamboge. — Sometimes the detection of gamboge becomes an object of medico-legal 
inquiries, as in the trial of Joseph Webb, for manslaughter, at the York Assizes, 1834 ( see Frazer’s Report). 
A few remarks, therefore, may not be useless as to the mode of proceeding, more especially as the subject is 
not noticed by Dr. Christison. To recognize gamboge in any substance supposed to contain it, proceed as 
follows : digest one portion of the suspected substance in alcohol or rectified spirit, and another portion in 
rectified aether. The alcoholic solution of gamboge possesses the following properties; its colour is orange red; 
on the addition of water it forms a bright yellow opaque emulsion ; if to this emulsion we add a few drops of 
liquor potassee, the yellow colour changes to bright red, and the liquid becomes immediately transparent and 
forms characteristic precipitates with the following substances : with the acids, or salts of gold, silver, palla- 
dium, lead, cobalt, or uranium, the precipitate is yellow; with the persalts of mercury, greenish yellow: with 
the chloride of manganese, orange red ; with sulphate of copper, brown ; with the protosalts of iron, a very 
dark precipitate. The precipitates produced with these metallic salts are gambogiates of the respective metals. 
The cetherial solution of gamboge has an orange red colour : dropped on water, it forms, when the aether eva- 
porates, a thin bright, yellow, opaque film or scum, which dissolves in caustic potash, forming a transparent 
red solution which conducts itself, with the above mentioned metallic salts, like the alcoholic solution. The 
only substance which, from its external appearance, might be confounded with gamboge is the substance im- 
properly called Botany Bay-gum (Resin of Xanthorrcea hostile.) The yellow colouring matter of saffron, 
rhubarb, turmeric, or zedeory, may, under some circumstances, be confounded with that of gamboge. The 
action of the before mentioned tests, however, readily distinguishes it. 
Medical Properties and Uses. — Gamboge is a violent cathartic, and is apt to produce vomiting, 
griping, and other symptoms, which in certain constitutions have terminated in death, as proved in the 
conviction of two vendors of Morrison’s pills ; into the composition of which it enters pretty largely. To 
obviate its unpleasant effects Cullen was accustomed to give it in small and frequently-repeated doses, 
as three or four grains, rubbed with a little sugar, every three hours, and found it operate gently. Great 
caution is required in its administration. It is as a hydragogue purgative that it is prescribed in dropsical 
affections, and is then generally combined either with calomel, cream of tartar, or squills. It has been 
supposed to be peculiarly efficacious in expelling the tape-worm ; but as a remedy in this case, its use is 
now very generally superseded by the oil of turpentine. It is soluble in a solution of potass, and is some- 
times preferred in this form in doses of from thirty t.Q forty drops, twice a day. 
Orfila classes it amongst the acrid poisons, and considers that it does not produce death by being 
absorbed, but by its exerting a powerful local action, in which the nervous system sympathizes. 
Dose. — The usual- dose is from two to five grains. 
Off. Prep. — Pilulee Cambogiee composites. L. E. 
