138 
SELECTED ARTICLES. 
hundred grains of two distinct specimens apparently of the 
same quality. 
First. Second. 
Resin heated at 400°, till it ceased to lose 
weight, ..... 
Arabin, or soluble gum, heated at 212°, till 
it ceased to lose weight, 
Moisture discharged by a heat of 270°, 
Woody fibre, .... 
Total 
74.2 
71.6 
21.8 
24.0 
4.8 
4.8 
trace 
trace 
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 accurary 
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, ren- 
ders it in medical practice convertible into a smooth and 
perfect emulsion, without any of the additions usually resorted 
to for that end. 
" I have nowhere met with any allusion to the question, in 
what principle the active properties of Pipe Gamboge reside. 
Since it consists of nothing else but gum and resin, the natural 
inference must be, that as gum is always bland and simply 
demulcent when pure, the acridity will be found to reside in 
the resin. This I have accordingly ascertained to be the 
case. The resin of gamboge, heated to 260° to drive away 
most of the ether, was administered as a purgative to several 
individuals alternately with gamboge itself; and both were 
found to occasion identically the same effects in kind — the 
resin, like the crude drug, occasioning profuse watery dis- 
charges, without pain or other uneasiness, in the dose of five 
