34 ORD. XIV. Rubiacez. CINCHONA. 
are distinguished by a pearly appearance. It is very soluble in ether, while 
cinchonine is very little so; this difference serves as well to distinguish their 
bases, as to separate them when united. Quinine likewise differs from cin- 
chonine in containing oxygen, and that in nearly as large a proportion as 
hydrogen. According to Mr. Brande, its ultimate components are nearly as 
follows :— 
Carbon: vir Seicderls: oA te aedenth 778RO 
PEE oe eet ie fon & bee 
a = NRE Seon eee EK 
WEVRO0 ee ys pa i 
100, 0 
Quinine, when melted, becomes idio-electric, and acquires the resinous | 
electricity with much intensity when rubbed with a piece of cloth. 
M. Robiquet, in the Journal of Science, has given an analysis of the two 
sulphates of quinine, but he found that the sub-sulphate lost a portion ofits 
acid during’ each crystallization; he has given the composition of this salt, 
both after the first and third crystallization, as follows :— 
100 parts of acid sulphate of quinine contain— 
MONE: ice et ec i 2 ee 
Quinine: 3 5 4.34 5 ee 5 
82.6 
100 parts of sub-sulphate, first crystallization, contain— 
BOR SS eee ee ee Ee 
Quinine <j 526 fg wi ae ogy 
| 90,3 
The sulphate of Quinine, when exposed to the temperature of 100° (212° 
Fah.) becomes luminous, especially when subjected to slight friction. This 
remarkable property was first remarked by M. Callaud d@Annecy. “MM. 
Dumas and Pelletier exposed about two or three ounces of the sulphate, en- 
closed in a glass flask, which they kept in a sand-bath for half an hour, to 
the temperature of boiling water, when it exhibited, on friction, a tolerably 
intense white light. On passing through the cork of the flask a metallic 
rod, ending in a point at the internal extremity, and by a ball at the oppo- 
site one, and applying it to the ball of the rod by a voltaic electroscope, shak- 
ing the flask before each contact, these gentlemen obtained the greatest se- 
