on a Substance possessing ike Properties of Tannin. 299 
that in the first experiment it was obtained as a product, and 
not as an educt, a fact which as yet has not been suspected. 
G. Gum ammoniac afforded a brownish yellow solution, the 
flavour of which was very bitter and astringent. 
By sulphate of iron, this solution only became of a darker 
colour, but did not form any precipitate. 
Nitrate of lime rendered it turbid, and produced a slight 
precipitate. 
Muriate of tin formed a copious yellow precipitate. 
Acetite of lead produced a similar effect : 
And gelatine yielded a bright yellow deposit, which was 
completely insoluble by boiling water. 
H. Asa foetida yielded a solution which also precipitated 
gelatine like the substances above described. 
I. Solutions of elemi, tacamahac, olibanum, sandarach, co- 
paiba, mastich, myrrh, gamboge, and caoutchouc, were next 
examined, but these, although they precipitated the metallic 
solutions, did not affect gelatine. It is possible, however, that 
they might have produced this effect, had they been subjected 
to a greater number of repetitions of the process. 
K. Sarcocol, in its natural state, as well as the gum sepa- 
rated from it by water, when treated with nitric acid, did not 
precipitate gelatine ; but produced effects on the metallic solu- 
tions similar to the above mentioned substances. 
L. Gum arabic afforded oxalic acid, but not any of the 
tanning matter. 
M. Tragacanth yielded an abundance of saclactic acid, of 
oxalic, and of malic acid, but not the smallest vestige of the 
artificial tanning substance. 
N. Manna, when treated with nitric add in the way above 
Qq * 
