RESEARCHES ON CINCHONINE. 
255 
is precisely owing to this circumstance that the method is disa- 
greeable and tedious. 
Aqueous prusssic acid is so rarely employed for medicinal pur- 
poses, that a test for that is scarcely required ; but the distilled 
waters of bitter almonds and of cherry-laurel, both of which con* 
tain prussic acid, are in daily use ; and it is highly desirable that 
the amount of the active ingredients should, under certain circum- 
stances, be ascertained with accuracy ; the process described an- 
swers admirably for the purpose. 
In general, cherry-laurel water is clear and transparent; the 
water of bitter almonds on the contrary, is usually milky from the 
presence of little drops of oil ; and it is requisite to mix the latter 
with 3 to 4 times its bulk of water to render it clear, otherwise 
the termination of the reaction is not seen distinctly. 
The method described may also serve to test the commercial 
cyanide of potassium ; and by its means I have unexpectedly found 
that the cyanide prepared according to the method described by 
me contains a comparatively small amount of cyanide of potas- 
sium. Two samples from two different preparations were ex- 
amined; the one furnished 63*5 per cent., the other only 59*99 per 
cent., of cyanide of potassium. — Chem. Gaz. March 1, 1851, from 
Liebig's Annalen, Jan. 1851. 
RESEARCHES ON CINCHONINE. 
By. Dr. Hlasiwetz. 
The author has obtained two essentially different bodies in the 
fractional crystallization of commercial cinchonine, the first of 
which has all the properties generally attributed to cinchonine. It 
crystallizes in moderately large shining prisms, is tolerably soluble 
in alcohol, furnishes quinoidine when heated, and sublimes in part 
to a matted tissue of fine crystals. When sublimed in a current of 
ammonia or hydrogen, remarkably brilliant prisms, more than an 
inch long, are obtained. This substance possessed exactly the 
