556 
RESEARCHES ON CINCHONINE. 
composition required by Regnault's formula, C 40 H 24 N 2 O 2 . The 
sublimed acicular crystals have the same formula. 
The second substance, which is obtained by successive crystalli- 
zation, separates from the alcoholic mother-liquor of the cincho- 
nine in beautiful hard rhomboidal crystals, which may be obtained 
of very considerable size and diamond lustre from ether, in which 
they dissolve very readily, which is not the case with cinchonine. 
These crystals become opake when heated, melt, and on cooling 
solidify to an amorphous mass, and furnish, neither alone nor in a 
current of ammonia or hydrogen, a trace of crystals. 
The analysis of this substance and of its platinum salt led to the 
formula C 20 H 12 NO 2 , which is the composition of the so-called 
/3-quinine detected by Heijningen in commercial quinoidine. The 
author calls it cinchotine. 
Commercial cinchonine moreover contains a tolerable amount of 
a brown basic resin, which was not further examined by the au- 
thor, but which appeared to be quinoidine. In a sample of beauti- 
fully-crystallized cinchonine from Merk's establishment in Darm- 
stadt, the author found the composition to agree with the formula 
which Liebig first proposed, C 20 H 11 NO. From this he concludes 
that neither Liebig's formula nor that of Regnault should give 
way for that recently advanced by Laurent, as they actually repre- 
sent certain kinds of cinchonine. The author has never been able 
to obtain Laurent's most recent formula with pure cinchonine ; ac 
cording to a series of most careful analyses, he constantly found 
numbers which led only to the formula C 40 H 24 N 2 O 2 . The pla- 
tinum salt places this formula beyond doubt, and proves at the 
same time that it should be halved, and written C 20 H 12 NO. 
In some attempts to oxidize cinchonine by various agents, the 
author always reobtained pure cinchonine. The cinchonine reob- 
tained was in every case submitted to analysis. In the treatment 
with chlorine, with manganese and sulphuric acid, with permanga- 
nate of potash, with nitric acid, with chloride of phosphorus, fur- 
ther after ebullition with an acid solution of bichloride of platinum, 
and fermentations with emulsine, the cinchonine comes out unalter- 
ed, or a resinous mass is obtained, as in the treatment with chlo- 
rine, from the solution of which pure cinchonine was precipitated 
by ammonia. The results of the analyses of such different samples 
