ON THE PRODUCTION OP VALERIANIC ACID. 129 
must compound himself. Consequently there exists no 
manufactory of medicinal preparations in the kingdom of 
Poland. 
From this report, it is clear that the medical regulations 
in the kingdom of Poland are efficient, and that the Apo- 
thecary in general stands on a high scientific and profes- 
sional footing, enjoys great protection from the government, 
and that the medical police regulations are strictly enforced 
for the benefit of the public in general — Pharm, Journ. 
from Corrcspondenz-Blatt fur Siid-Deutschland. 
ART XXVI. — ON THE PRODUCTION OF VALERIANIC ACID 
AND A NEW SUBSTANCE FROM CASEINE. 
By Justus Liebig. 
When cheese prepared from fresh or sour milk, and 
which has been well pressed and freed as much as possible 
from adherent butter, is kept with an equal weight of 
hydrate of potash (or solution of potash, which would crys- 
tallize on cooling) in a state! of fusion until hydrogen gas 
is evolved along with ammonia from the fusing mass, and 
the residue is then dissolved in hot water, slightly super- 
saturated with acetic acid, and the filtered solution allowed 
to cool, a quantity of very minute needles separate, which 
are very sparingly soluble in cold water and insoluble in 
alcohol and aether. By repeated solution in water to which 
some carbonate of potash is added, and precipitated with 
acetic acid, this body is obtained in perfectly white silky 
needles. From a preliminary analysis, which requires con- 
firmation, its composition is expressed by the formula C 16 
NH 9 5 . Although readily soluble in alkalies, it combines 
12 
