288- 
CINCHONA. 
cid matter, which becomes brittle when cold, and is very bitter; this 
matter he digests in hot water, acidulated by sulphuric acid, and the 
liquor, when cold, gives pure sulphate of quinine, in the form of 
perfect white crystals. These crystals are soluble in boiling water, 
especially if it is weakly acidulated; they are but little soluble in 
cold water, without the addition of an acid. 
Chemical Properties of Cinchonine and Quinine. 
Cinchoniue is white, translucent, crystallizable in needles, and solu- 
ble only in seven hundred parts of cold water. If dissolved in alco- 
hol, or an acid, its taste is powerfully bitter, and resembles that of 
the grey bark. It is dissolved in very small quantities by the fixed 
or volatile oils, and sulphuric ether. With acids, it forms salts which 
are more or less soluble. According to the analysis of M. Brande, 
cinchonine consists of about — 
Carbon 80.20 
Nitrogen 12.85 
Hydrogen 6.85 
99.90 
. Quinine is white and incrystallizable ; it is as little soluble in 
water as cinchonine, much more bitter to the taste, as are also most 
<)f its salts, which are distinguished by a pearly appearance. It is 
very soluble in ether, while cinchonine is very little so: this differ- 
ence serves as well to distinguish their bases, as also to separate 
them when united. Quinine likewise dilFers from cinchonine in con- 
taining oxygen, and that in nearly as large a proportion as hydrogen. 
According to M. Brande, its ultimate components are nearly as 
follows : — 
Carbon 73.80 
Nitrogen 13. 
Hydrogen., 7.65 
Oxygen 6.66 
100. 
Medical Properties of Peruvian Bark. There is no 
satisfactory account at what time, or by what means, the efficacy of 
Peruvian bark, as a medicine, was first discovered ; and it is even a 
disputed point, whether or not it was known to the native Americans 
