118
ILLUSTRATIONS OF INDIAN BOTANY.
flame and odour of burning wood, and with a mere trace of earthy residue, and therefore apparently woody fibre, or lignin. The analysis of two samples gave results nearly concordant,, as follows. One hundred grains were used, and all visible fragments of wood were excluded.
First. Second.
Resin, dried in oil-bath at 400° 64.3 65.0
Arabin, dried at 26U° „... 20.7 19.7
Fecula, dried at 212° 6.2 5.0
Lignin, dried at 212° 4.4 6.2
Moisture.... 4.0 4.2
Total. . 99.6 100. 1 The proportion between the gum and the resin is here identically the average proportion already mentioned as existing in Pipe gamboge; so that, on simply abstracting the fecula and woody fibre, an article is constituted of precisely the same chemical composition. This cir- cumstance, coupled with the presence of the particular principle fecula, and the vesicular structure of the cakes, renders it extremely probable, if not certain, that cake gamboge is not simply a natural production, but rather a manufactured substance — an adulteration For in the first place, it is the pure exudation plus so much impurity ; secondly, fecula is not known to be pro- duced from the trunks, branches, or leaves of plants belonging to that part of the botanical system in which the true Gamboge tree undoubtedly will be found to be properly placed, and it is therefore almost impossible that its presence depends on some mere variety in the period of collection or other circumstance in vegetation ; and thirdly, the vesicular texture, so different from the compact, uniform texture of Pipe gamboge, is exactly what might be expected from the process of wetting the exuded juice, beating it up with other pulverulent substances, and then drying it. It mi^ht be objected that eleven per cent, of foreign matter is a small addition for an adulteration. But this amount may, after all, be quite equivalent to the grower's profit from the pure article ; and it will presently be seen, that a larger proportion of adulteration may so dilute the yellow tint of the mixture as to render it almost unmarketable,"
Chemical Composition of coarse Gamboge.
First. Second.
" Resin, dried in the oil-bath at 380° 61 4 35.0
Arabin, dried at 212° 17.2 14.2
Fecula, dried at .-12° 7.8 19.0
Lignin, dried at 212° 7.8 2^.0
Moisture disengaged at 350° 7.2 10.6
Total 101.4 100.8"
Chemical Composition of Ceylon Gamboge. " The following results were obtained from three analysis of Mrs. Colonel Walker's sps- eimens, evidently different in purity. The quantity used was one hundred grains.
First. Second. Third.
Resin, heated at 400° 68.8 71.5 72.9
Arabin, dried at 240° 20.7 18.8 19.4
Fibre of wood and bark, at 212° 6.8 5.7 4.3
Moisture 4.6 not ascertained.
Total 100.9 96.0 96.6
Moisture not reckoned. Here it is evident that the proportion of gum and resin to one another is as nearly as pos- sible the same, with their proportion in some specimens of fine Pipe gamboge."
" November 28fh. — To the observations made above, on the external characters and com- position of the different kinds of Gamboge, it may be well here to annex a brief notice of the gambogioid juices obtained from two trees, which have been at different times supposed by some to yield the genuine drug, namely, the Garcinia cambogia, and Xanthochymus pictorius.
