44 
ON THE GAMBOGE TREE OF SIAM. 
known there to produce a sort of gamboge, not, however, known 
in the ccommerce of Europe. Resting on a peculiarity in the 
structure of the anthers, which are circumscissile, or open trans- 
versely by the separation of a lid on the summit, he constituted a 
new genus for this plant, and called it Hebradendron cambogioides. 
At the same period the author examined the properties of this gam- 
boge, and found that it possesses the purgative action of the com- 
mercial drug in full intensity, and that the two kinds agree closely 
also, though not absolutely, in chemical constitution. 
At an earlier period Dr. Roxburg described, in his Flora Indica, 
another species of Garcinia, under the name of Garcinia pictoria, 
which inhabits the hills of Western Mysore, and which also was 
thought to produce a sort of gamboge of inferior quality. In 1847 
specimens of the tree and its exudation were obtained nearNuggur, 
on the ghauts of Mysore, by Dr. Hugh Cleghorn, of the East India 
Company's service ; and the author, on examining the gamboge, 
found it all but identical with that of Ceylon in physiological action, 
in properties as a pigment, and in chemical constitution. The 
same plant, with its gamboge was about the same time observed by 
the Rev. F. Mason, near Mergui in Tavoy, one of the ceded Bur- 
mese provinces. 
A third species inhabiting the province of Tavoy, and also pro- 
ducing a kind of gamboge, was identified by Dr. Wight in 1840 
with Dr. Wallich's Garcinia elliptica, from Sylhet, on the north-east 
frontier of Bengal. Its exudation was long thought to be of low 
quality ; but, although this substance has not yet been examined 
chemically, it has been stated by Mr. Mason to be, in his opinion, 
quite undistinguishable as a pigment from Siam gamboge. 
It is a matter of doubt whether Graham's character is sufficiently 
diagnostic to be a good generic distinction. But it was shown by 
Dr. Wight in 1840, that a well-characterised section at least of the 
genus Garcinia consists of species which have u sessile anthers, 
flattened above, circumscissile, and one-celled ;" and that all these 
species, and no others, appear to exude a gum resin differing pro- 
bably very little from commercial gamboge. 
Still the tree which produces Siam gamboge, the finest and only 
commercial kind, continues unknown. A strong presumption how- 
ever arose, that the last species was the Siam tree, as it grows in 
the same latitude with the gamboge district of Siam, and not above 
