ON GAMBOGE. 
131 
nearly colorless, and dried at 100° C; this yielded, when 
finely powdered, a yellowish white powder. By analysis 
he found its composition as follows: 
Carbon, 
Hydrogen, 
Oxygen, 
I. 
II. 
44.00 
44.94 
6.22 
6.11 
49.7S 
48.95 
100.00 
100.00 
From these analyses it follows, that this substance has the 
elementary composition of starch, or anhydrous sugar, as 
may be seen in comparing the annexed table. 
Gum of Starch or Anhydrous 
Gamboge. Gum Arabic. Cane Sugar. 
Carbon = 44.94 42. 5S 44.91 
Hydrogen = 6.11 6.37 6.11 
Oxygen == 4S.95 51.05 4S.98 
100.00 100.00 100.00 
This composition led to the inference that the gum 
treated with nitric acid might be converted into mucic 
acid, or, by treating with dilute sulphuric acid, into sugar, 
an inference which experiments proved to be well founded. 
Gamboge owes its color to the fatty acid; with water it 
forms an emulsion, the water dissolving the gum, and a 
small quantity of a brown-red coloring matter, into a mu- 
cilage, in which the coloring matter is held in suspension. 
This examination finally proves, that the resin of gamboge 
resembles a fatty acid, that it contains a small quantity of a 
peculiar red-yellow coloring matter, soluble in water and 
alcohol, and a greater quantity of a gum-like substance, 
having the. composition of flour of starch, which, by sul- 
phuric acid, may be converted into sugar not capable of un- 
dergoing fermentation. 
