196 
ON DIGITALIS. 
ART. XLVIL— PHARMACEUTICAL AND TOXICOLOGICAL 
EXPERIMENTS ON DIGITALIS. By M. Bonjean. 
When the powder of the leaves of Digitalis is treated 
by displacement with water, a very bitter solutionis obtain- 
ed, which contains nearly the whole of the active principles. 
On acidulating, sufficiently, the solution with sulphuric acid, 
a green resin is separated, in which appears to reside the 
diuretic virtues of this plant. This resin is insoluble in 
sether, soluble in dilute alcohol, and the alcoholic solution 
may be mixed in every proportion with water, without the 
resin being precipitated, although it is insoluble in water. 
Powder of Digitalis, exhausted with water, abandons 
subsequently to alcohol the whole of the chlorophylle, mixed 
with a fresh proportion of resin, which appears to be of the 
same nature as that which sulphuric acid throws down from 
the aqueous infusion of the powder. After this two-fold 
treatment, the Digitalis is reduced to about half its weight. 
The powder, exhausted by water and alcohol, only contains 
a small quantity of a green coloring substance, or chloro- 
phylle, which may be easily isolated by means of sulphuric 
sether. 
One oz. of Digitalis powder furnishes about IS to 20 grms. 
of a green resin, and 14 to 15 grms. of chlorophylle. It is 
to this latter substance that the tincture of Digitalis owes its 
beautiful green color. It is therefore obvious that this color 
has not the least influence on the properties of the remedy, 
and that the tincture will be the richer in green coloring 
substance the weaker the alcohol employed in its prepara- 
tion. 
To be efficacious as possible, the tincture of Digitalis should 
be prepared with alcohol of 0.975 to 0.972, and not with al- 
cohol of 0.829 spec, gray., as recommended by all authors. 
