i5o PLANT AND ORGANIC CHEMISTRY 
It had a slightly acid reaction with litmus. An emulsion was 
formed on the addition of water to the alcoholic residue. A 
measured quantity of it was evaporated, dried, and weighed. 
It amounted to 3.4 per cent., 0.4 per cent, of the alcoholic 
residue was insoluble in water. Tannin, gallic acid, and alka¬ 
loids were tested for and with negative results. 
The liquid from the aqueous treatment of the alcoholic resi¬ 
due was rendered alkaline, and boiled with Fehling’s solu¬ 
tion, and there was no reduction. Boettger’s bismuth test was 
also tried and with negative results. The aqueous portion 
was boiled with acid and examined in the usual way for glu- 
cosides; the results were negative. 
One volume of the aqueous solution was mixed with three 
volumes of stronger alcohol. It was placed on ice, and after 
some time a white precipitate formed. The precipitate was 
collected and dissolved in water. It frothed on shaking. On 
addition of a concentrated solution of caustic baryta, a creamy- 
white precipitate of saponin-baryta was obtained. Sulphuric 
acid gave the usual red-violet color reaction with the precipi¬ 
tate from the alcoholic aqueous solution. 
The method of successive agitation of an aqueous extract 
with solvents already described was followed. Petroleum 
spirit on evaporating left a resinous substance. The residue 
separated by chloroform from an acidified solution was a 
brownish-colored substance. It was soluble in water, and 
frothed on shaking. It was colored red-violet by sulphuric acid, 
and the aqueous solution was precipitated by barium hydrate. 
Chloroform separated a brownish solid from an alkaline aque¬ 
ous solution. It was precipitated by barium, colored red- 
violet by sulphuric acid, and its aqueous solution frothed on 
shaking. This brownish residue was identified as saponin. 
Extract (4), the Yellow Base of the Leaf. 
The residual powder, dried from all traces of ether, was 
macerated with hot alcohol. The alcoholic extract was a cur¬ 
rant-colored liquid, and slightly acid in reaction. The liquid 
became clear on standing, and a creamy-white solid, identi- 
