I 
ON THE PURPLE FOXGLOVE. % 101 
the evaporation of the two solutions a part of the matter sepa- 
rated in the form of white flakes, and on the sides of the ves- 
sel some yellowish stripes formed, probably arising from an in- 
cipient decomposition of the digitaline by the heat employed 
for the evaporation. The best solvent for digitaline is alcohol. 
It takes up a large portion in the cold, and still more when 
heat is applied. The boiling solution, however, does not form 
any deposit on cooling. When digitaline has been purified 
by aether, it appears to dissolve with rather less facility in al- 
cohol. The alcoholic solution, left to spontaneous evapora- 
tion, deposits the digitaline partly in a pulverulent, partly in 
a crystalline state. Towards the end of the evaporation the 
liquid often forms a kind of hydrated mass, which, after en- 
tire desiccation, takes the form of warty crusts. Concentra- 
ted sether dissolves so much the less of this bitter principle, 
the lower its density. 
Action of Acids. — We have not been able to form any 
combination of digitaline with acids. This result was proba- 
ble from the neutrality of this principle. 
Digitaline becomes black directly it is placed in contact 
with concentrated sulphuric acid, and soon forms a solution 
which appears blackish-brown, when examined in a thin lay- 
er ; after some time this colour passes successively into red- 
dish brown, smoky amethyst, pure amethyst, and finally to a 
beautiful crimson. If during this interval a portion of the 
solution is added to a small quantity of water, a clear beauti- 
ful green solution results. Concentrated hydrochloric acid 
quickly dissolves it, communicating to the liquid a yellow tint, 
which after a few instants changes to a beautiful emerald 
green, and becomes darker and darker until it is of a dark 
green. In about an hour's time the liquor becomes turbid, 
and the matter at first dissolved is precipitated in the form of 
green flakes floating in a greenish yellow liquid. In the 
course of two days the flakes have become of a blackish 
green colour. 
