CHEMICAL CONSTITUENTS OF THE CINCHONA BARKS. 67 
From the few, but striking, analytical results which are here 
summarized, it is evident that external characteristics, including 
histological relations, scarcely afford a criterion for the chemical 
valuation.of Cinchona barks. If we must abandon the attempt of 
determining for one and the same Cinchona a constant average 
percentage, this applies in a very much higher degree to the com- 
mercial varieties. 
Between the complete absence of bases, and the maximum of 
more than 13 per cent. of quinine," which has been observed up to 
the present time, numerous gradations occur regarding quality and 
quantity. 
The barks of the roots appear regularly to be richer in alkaloids 
than those of the trunks. De Vrij, in 1869, obtained from the 
root bark of C. succirubra, grown in Ootacamund, 12 per cent. of 
alkaloid. 
Of the bark of Calsaya Ledgeriana, grown in Java, Bernelot 
Moens, in 1879, examined 80 specimens. They afforded a mini- 
mum of 1.09 per cent., and a maximum of 12.50 per cent. of 
alkaloids, although only in 13 cases less than 5 per cent. The 
quinine varied between 0.8 and 11.6 per cent. The same bark 
furnished in following years, according to the estimations of the 
above-named chemist, in 100 parts of artificially (page 34) dried 
bark :— 
1880 1881 
Total alkaloids, in minimum, 4. , 3 
fi " * maximum, 9- 9- 
Quinine, in minimum, 2.3 1.2 
« -“ maximum, 8. 8.1 
In the Indian C. succirubra, whose total alkaloid readily amounts 
to from 6 to Ir per cent., as was, moreover, already known to be 
the case with the original Red Cinchona of South America, the 
amount of quinine is small. The Indian bark often affords 
but 1 per cent., more rarely about 4 per cent. of quinine, and very 
commonly from 3 to 4 per cent. of cinchonidine. In the year 1881 
the amount of total alkaloid from the bark of C. succirubra har- 
vested in Java varied between 3.2 and 9.8 per cent., that of quinine 
from 0.4 to 2.5 per cent., and of cinchonidine between 1.3 and 5.2 
per cent. 3 
The above analyses of Bernelot Moens refer to average spect- 
mens from separate packages, the weight of which was from 200 
kilograms, and even less, to some thousands of kilograms. 
The wood of the roots and of the trunks of Cinchona, the latter 
1 Blue Book, 1870, p. 282. Bernelot Moens, in 1882, obtained as much as 13.61 per 
cent. of alkaloids from C. Ledgeriana. 
