184 ON DIGIT ALIC ACID AND THE DIGIT ALATES. 
Digit a late of Lead. — A white, heavy, insoluble salt. 
Digitalate of Copper. — A greenish, soluble salt. 
Digit alate of Silver. — A white salt, insoluble in water, 
but soluble in nitric acid. 
A solution of digitalate of soda gives, with protosulphate 
of iron, an abundant rlocculent precipitate ; with the per- 
acetate of iron it produces no effect ; these reactions prove, 
according to the author, that digitalic acid cannot be mis- 
taken for gallic acid. 
This acid exists, probably, uncombined with digitaline, 
for after having treated the watery extract with alcohol, 
an abundant brown precipitate is obtained, which is devoid 
of bitterness, but possesses an acid reaction, and digitalic 
acid may be obtained from it. 
M. Morin observes, that the peculiar properties of digi- 
talic acid, as such, appear to him to be sufficiently establish- 
ed ; though it may, he states, be objected, that it is formed 
under the influence of the substances, especially of barytes, 
employed to obtain it ; but to this objection it is replied, 
that the juice of the digitalis possesses an acid reaction as 
soon as it is procured; that the dry leaves treated with 
water, alcohol, or aether also yield acid solutions ; if the al- 
coholic or aethereal solution, obtained during the preparation 
of the acid, be saturated with oxide of lead, the liquor re- 
mains bitter, and a precipitate is formed ; if this be washed 
in the water and alcohol, and then treated with hydrosul- 
phuric acid, the excess of which is to be expelled, a very 
acid solution is obtained, from which digitalic acid is obtain- 
ed by crystallization. This process the author thinks may, 
perhaps, be better than that which he has described, unless 
it be wished to obtain the bitter principle at the same time; 
in this case the action of the base employed is not sufficient- 
y energetic to allow of the formation of a secondary pro- 
duct; the same effect may be produced with carbonate of 
ead. — Ibid, from Journ. de Pharm. et de Ch. 
