ON THE PURPLE FOXGLOVE. 103 
searches ; afterwards will come the action of sulphuric acid 
and that of acetic acid. 
The conversion of digitaline into an acid astringent princi- 
ple, on the one hand by the influence of heat, and on the 
other by potash, joined to the slight alteration which we ob- 
served during the evaporation of the aqueous solution, indi- 
cate in a practical point of view, that the employment of 
heat must be very unfavourable in making the pharmaceutical 
preparations which have digitalis for basis, and that care must 
be taken not to add alkaline salts to them. 
We have seen that pure digitaline is scarcely soluble in 
water ; we must not, however, conclude from this that this 
agent is unfit to dissolve the active principle of the plant. In 
the Digitalis it occurs in combination with saline and extrac- 
tive matters, which favour its solubility in this medium. 
Digitaline which has not been purified by aether retains, as 
above stated, a green matter, an odoriferous substance and a 
crystallizable principle, and is known by its peculiar odour, 
calling to mind that of Digitalis. It dissolves but imperfect- 
ly in hydrochloric acid, so that the liquor remains turbid, but 
presents the same intense green colour. It moreover leaves 
some light flakes on solution in acetic acid. 
The author has not submitted the digitaline to elementary 
analysis, not having been able to obtain it perfectly pure in 
sufficient quantity, the amount in the plant being extremely 
minute. — Chem. Gaz. 
t 
