1S4 
ON AMORPHOUS QUININE. 
verizable in the cold. The operation of powdering imparted 
to it an extraordinary degree of elasticity. All these 
samples were completely insoluble in cold water, but scan- 
tily soluble in hot water, imparting to the latter a strongly 
bitter taste. I may here, however, observe, in passing, that 
some commercial specimens which I have since seen are 
soluble in cold water, arising from a considerable admixture 
of other substances ; differing, also, from the same cause, in 
many of the following properties : — 
All the first samples I speak of dissolved in alcohol, in 
the proportion of one part to two of the menstruum ; and 
from this alcoholic solution, water precipitates copious, yel- 
lowish-white, resinous flakes, which cohere into a mass like 
the original quinoidine. Dilute mineral acids, as well as 
most of the organic acids, dissolved my samples entirely, and 
by adding a sufficient amount of the substance, became 
completely neutralised. From these solutions in acids, 
ammonia and alkaline carbonates precipitated resinous 
flakes. On agitating the fluid containing these flakes and 
the flocculent precipitate, with an equal volume of ether, 
the precipitate dissolves in the ether, with the exception of 
a dark-brown residue. On evaporating the ether, a resin- 
ous mass is obtained, having all the properties of an organic 
alkaloid. 
Its salts are precipitated by tannic acid. Chloride of 
platinum produces, in its solution in hydrochloric acid, a 
yellow precipitate. Moreover, it dissolves completely in a 
solution of sulphate of copper, with the separation of oxide 
of copper. Now there exists no resin, nor, indeed, any 
other substance similar to resin, which possesses this pecu- 
liar property. 
These observations can leave no doubt whatever as to 
the chemical character of a considerable proportion of the 
residue to which the term quinoidine has been applied — 
namely, that it is a true organic base. 
On subjecting the purified substance to elementary analy- 
sis, the following were the results : — 
