ON DIGITALIC ACID AND THE DIGIT AL ATE S. 181 
ART. L.— ON DIGITALIC ACID AND THE DIGIT ALATES. 
By M. Pyrame Morin. 
To prepare this acid, the leaves of the plant are to be 
treated with hot water ; the infusion is acid, and is to be 
evaporated on the water-bath to the consistence of a thick 
syrup ; to the residue a large quantity of alcohol is to be 
added until it produces no further precipitation ; it is to be 
suffered to remain for some days till a deposit is formed, 
which ought not to be bitter, but which is so if the alcohol 
be too strong. 
The liquid is then to be filtered, and distilled in a water- 
bath till it becomes a thick extract, which is to be treated 
with pure sulphuric aether, and kept at a moderate heat for 
an hour and eventually boiled ; this operation is to be re- 
peated several times. 
The sethereal tinctures thus obtained are acid, and have a 
slightly greenish-yellow colour, especially the first portions. 
By this process the bitter principle, or digitaline, and the 
digitalic acid are dissolved; to this sethereal solution barytes 
in fragments is to be gradually added, which forms a yellow- 
ish precipitate, and when any remains insoluble, or the solu„ 
tion restores the blue colour of reddened litimus, enough ba- 
rytes has been added. 
The liquor, which contains only digitaline, but not per- 
fectly pure, is then to be filtered. The precipitate is to be 
collected, which is to be washed with a3ther to remove all 
the bitterness, and then with alcohol, till it passes but slight, 
ly or not at all coloured. 
The precipitate is to be diffused through cold water and 
mixed with sulphuric acid to precipitate the barytes ; and 
it is better to leave some digitalate of barytes undecomposed 
than to add too much acid. By filtration, a strongly acid, 
