66 CINCHONA BARKS. 
the, indeed, very different quinamine, may be summarized as 
' follows :— 
a. Hydrated crystals are formed by Quinine, Quinidine. 
Cinchonine, Cinchonidine. 
Not containing water of crystallization | Quinamine, Homoquinine. 
b. Abundantly soluble inether . . | ae oe 
Slightly " Ven ; : Cinchonidine, Cinchonamine. 
Very sparingly “ we poe Cinchonine. 
c. Levogyrate solutions afforded by : Quinine, Cinchonidine. 
Pextrouventl ie ate Quinidine, Cinchonine, 
8Y Quinamine. 
Quinine, Quinidine, 
d. Thalleioquin is afforded by 2 ae Homoquinine. 
“ iamde. ot 1 Cinchonine, Cinchonidine, 
z . Quinamine. 
e. Fluorescence is displayed in the acid 
solutions of salts of . ‘ a Quinine, Quinidine, Homoquinine. 
No fluorescence is displayed by Cinchonine, Cinchonidine, Quinamine. 
The amount of alkaloids' which the Cinchona barks contain is 
subject to considerable variation. Karsten pursued this investi- 
gation, e. g., in the Cinchona corymbosa discovered by him, the 
trunks of which, at elevations of 3500 meters (11,375 feet), on 
the South-Colombian volcanoes, Cumbal and Chiles, furnished no 
quinine. Barks grown at other parts of this district afforded 34 per 
cent. of quinine, and those from the central elevated regions, 
which this handsome species’ inhabits, 114 to 3%4 per cent. of sul- ° 
phate of quinine. Cinchona lancifolia, taken in the neighborhood 
of Bogota from one and the same mountain ridge, contained in 
the bark of the branches no quinine, or only insignificant traces of 
the same, while trunk bark from another place gave 2, and even 
4%, per cent. of sulphate of quinine. 
Variations not less in extent have been proved by De Vrij? to 
occur with Cinchonas grown in Java. Calisaya trunk barks, 7 
years old, gave 0.64 per cent., and those of 6% years, from another 
plantation, 5 per cent. of total alkaloids. In 1873, he found in the 
bark of Cinchona officinalis, from Ootacamund, 1 Y to g.1 per cent. 
of quinine. 
In the bark of Cinchona pubescens Vahl, which, indeed, is un- 
salable, Hesse, in 1871, found no alkaloid at all. 
1 The analytical statements frequently tefer to sulphate, and not to the amount of the 
bases themselves, directly separated from the bark. 100 parts of sulphate of quinine = 
64 of quinine; 100 of quinine = 135 of sulphate. The Dutch analyses state the per- 
centage of alkaloid of barks dried at 100° C. (212° F.); these values, therefore, on ac- 
count of the average amount of water, 13.5 per cent. (see p. 34), must be multiplied by 
0.865, in order to correspond to an ‘ie iiteed vibe: gh te raed 
* Figure: plate X of the Flora mentioned in section 18, No. 12: also copied there- 
from (uncolored) in Markham’s publication (section 18, No. 21 of this work), 
* Pharm. Fourn., V1 (1864), p. 16. 
