already mentioned as existing in 
coupled with the presence of the particu- 
- lar principle fecula, and the vesicular struc- 
e of the cakes, renders it extremely 
probable, if not certain, that Cake Gam- 
boge is not simply a natural production, 
ut 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 
plants belonging to that part of the bo- 
tanical system in which the true Gamboge 
Tree undoubtedly will be found to be pro- 
perly placed, and it is therefore almost im- 
. possible that its presence depends on some 
. Were variety in the period of collection or 
Other circumstance in vegetation; and 
thirdly, the vesicular texture, so different 
rom the compact, uniform texture of Pipe 
 Gamboge, is exactly what might be ex- 
Pected from the process of wetting the ex- 
uded juice, beating it up with other pulve- 
relent substances, and then drying it. Tt 
| might be objected that eleven per cent. of 
4. 5» Matter is a small addition for an 
1 adulteration, But this amount may, after 
d » be quite equivalent to the grower's 
Profit from the pure article; and it will 
T e ed that a larger proportion 
Eo. ay so dilute the yellow 
mixture as to render it almost 
ketable, 
z 
a 
p We cannot doubt that the resin of Cake 
qua. 56 possesses the same effects on the 
| dy vit that of the Pipe variety. So 
3. n. may be passed over. 
^ Con e Coarse Gamboge of some Eng- 
ggists is classed by oth i 
C ' Vaticty, y others with the 
Since chem; 
ten is 
VOL. 11, 
Mposition of what has been de- 
ON THE SOURCES AND COMPOSITION OF GAMBOGE. 
241 
scribed above as Cake Gamboge, while the 
other, which is greatly harder, more earthy 
in its fracture, and grayish-yellow in tint, 
both in mass, in powder, and in emulsion, 
evidently owes these differences to nothing 
else but a larger proportion of the same, 
or at least a similar, adulterating ingredi- 
ent. The composition of these specimens 
was as follows for 100 grains. 
Ree; dned i " ;: First. Second, 
esin, dried in the oil- 
beth àt 8809777. ar SA 
Arabin, dried at 212°... 17.2 14.2 
Fecula, dried at 212^ . 7.0 19.0 
Lignin, dried at 212°.... 7.8 22.0 
Moisture disengaged a 7.2 10.6 
Total... 1014 ^ 100;8 
With the ligneous fibre I have also includ- 
ed a trace of sandy particles and other im- 
purities. 
Ceylon Gamboge, as I have seen it, 
is usually in small irregular fragments, but 
as originally collected, is in flattish round 
masses, as if moulded in shallow bowls, 
weighing about a pound or upwards; and 
it appears to be composed of aggregated 
irregular tears, with interspaces and cavi- 
ties, which are lined with a dark, powdery 
matter, or with a powder of an earthy ap- 
pearance. Altogether it seems a very 
coarse article. But on attentive examina- 
tion it will be found, that the tears, of which 
by far the greater portion of it is compos- 
ed, present the compact texture, smooth 
fracture, and glimmering lustre of fine 
Pipe Gamboge ; that its powder has an in- 
tense Gamboge-yellow tint; and that a 
smooth emulsion is very readily formed by 
it with the wet finger. Dr. Duncan, in- 
deed, has stated, that it has not the pro- 
perties of true Gamboge ;! and I know he 
referred to its not being sufficiently emul- 
sive to form a smooth mass with water for 
the use of the painter. But in this he is 
not quite correct. The specimen of con- 
crete juice adhering to the bark, which was 
1 Edinburgh New Dispensatory, Ed. 1830, Art. 
Gamboge. 
Q 
