GROWN ON THE NEILGHERUY HILLS. 
241 
nation, that the leaves of C. succirubra (even in the fresh green state) are worthless as a 
source of febrifuge alkaloids. They appear to owe their bitterness to the presence of 
quinovin, a substance which may probably possess some tonic properties. 
12. Next to the C. succirubra , the most important species we at present possess is the 
C. officinalis , whose varieties yield the crown barks. The three varieties, Bonplandiana , 
Uritusinga, and Crespilla , greatly resemble one another, and appear to differ even less 
among themselves than some individuals of C. succirubra , of which botanists recognize 
but one variety. 
Of the varieties, var. Bonplandiana is the most important, since upwards of 750,000 
are now growing on the plantations. This variety also comprises the most advanced 
trees, whose identity with their name could be considered certain. The trunk bark of a 
tree from Dodabetta plantation yielded in the dry bark the following percentages:— 
Total alkaloids (hydrated). 3'6 per cent. 
Alkaloid soluble in ether (quinine) . 2'8 „ 
Cinchonine and cinchonidine. 0‘8 „ 
Sulphate of quinine obtain crystallized. 2*8 „ 
The fresh bark contained 66 per cent, of water. 
A second specimen of somewhat different bark yielded— 
Total alkaloids (hydrated). 3'8 per cent. 
Alkaloid soluble in ether (quinine) . 3 - 0 „ 
Insoluble in ether (cinchonine) . 0*8 „ 
Crystallized sulphate of quinine obtained. 2 - 9 „ 
Hence it appears that even at the present age, the trees of C. officinalis , var. Bonplan¬ 
diana , yield a bark of admirable quality, and nearly equal to the fine Calisaya bark of Bo¬ 
livia. In the last-quoted analysis no alkaloids were found, except quinine and cinchonine, 
the latter occurring in but small quantity. I am of opinion that this bark possesses, for 
manufacturing purposes, certain advantages over the red bark, that in some measure 
tend to compensate for the smaller yield and slower growth of the tree producing it. 
The crown bark yields its alkaloids with greater ease, owing to the small amount of 
resin and colouring matter with which they are associated. 
13. An analysis of similar bark that had been renewed six months under moss, 
yielded— 
Total alkaloids (hydrated). 6'8 per cent. 
Alkaloids soluble in ether (quinine) . 4*8 „ 
Cinchonine and cinchonidine. 2'0 „ 
Sulphate of quinine obtained crystallized. 4T „ 
This analysis shows that the mossing process, though only applied for six months, 
has greatly increased the yield of alkaloids in this variety of bark. 
14. I would here beg permission to state, without advancing any new hypothesis, such 
known facts that appear in a great measure to explain the increased amount of alkaloids 
produced by mossing the bark. 
The injurious action of light on the cinchona bark and alkaloids was clearly pointed 
out many years ago by Pasteur,* a chemist, to whom our present knowledge of these 
alkaloids is largely indebted. It is on account of this destructive action of light that 
he recommended shielding the bark from sunlight while drying ; pure, colourless solu¬ 
tions of the alkaloids are soon coloured brown and partially decomposed by exposure to 
sunshine. The same change takes place when dry or moist sulphate of quinine is 
isolated. 
15. In order to verify these facts in the climate of the Neilgherries, I prepared from 
red bark pure colourless solutions of each alkaloid, and sealed them up in vacuo in glass 
tubes, in order to eliminate possible oxidation. After three days’ exposure to the sun’s 
rays they all became coloured, while similar solutions preserved in the shade remained 
unaltered. The tube containing quinine was opened after a fortnight’s exposure, and 
its contents examined. It was then found that a considerable quantity of a dark- 
coloured, resinous substance had been formed, and that much of the alkaloid had lost its 
power of crystallizing. I would submit that these circumstances are very significant 
when applied to the elucidation of the cause of some of the changes occurring in the 
* ‘Comptes Kendus,’ xxxvi. p. 26, and xxxvii. p. 162. Also £ Koppo Jahresbericht,’ 1853. 
p. 419. 
YOL. IX. R 
