98 
ON THE PURPLE FOXGLOVE. 
bitter principle, still retaining some traces of oil, salts and ex- 
tractive substances. 
This mass is washed with a little distilled water, which re- 
moves any deliquescent salts, without perceptibly dissolving 
the bitter principle. It is left to drain, and again dissolved in 
boiling alcohol, with the addition of a sufficient quantity of 
charcoal, washed with hydrochloric acid ; it is then boiled and 
thrown on a filter. The liquid passes colourless ; left to spon- 
taneous evaporation in a warm chamber, the substance is 
partly deposited on the sides of the dish in the form of thin, 
light, semi-transparent layers, and partly at the bottom of the 
vessel in the form of agglomerated whitish granular flakes. 
The perfectly dried product is reduced to powder and 
treated with rectified aether. It is left 24 hours in contact, 
then boiled and filtered. This stthereal solution, on spontane- 
ous evaporation, leaves a slight crystalline white layer, con- 
sisting of a certain proportion of the bitter principle, a trace 
of green oleo-resinous matter, a substance whose odour calls 
to mind that of Digitalis, and of a substance crystallized in 
beautiful white needles, without smell, of an acrid and rather 
sharp taste, insoluble in water and alcohol, fusible at about 
302° Fahr., and upon cooling forming a yellow radiated crys- 
talline mass. The small quantity we have been able to iso- 
late has not permitted us to ascertain its other properties. We 
shall pursue the investigation of it as soon as we obtain a suf- 
ficient quantity. 
An experiment made on 250 grs. of aqueous extract of 
digitalis, prepared with care, which was redissolved succes- 
sively in alcohol and water, did not enable us to obtain the 
bitter principle solid and completely isolated. We thence 
concluded that the heat required for preparing the extract, al- 
tered this matter still combined with the bodies which accom- 
pany it in the plant. 
Another experiment made on 2 qts. of juice of fresh digitalis, 
yielded a beautiful product ; but the very small proportion 
seemed an objection to this method of preparation, indepen- 
