4 QUINOEOGY OF THE EAST INDIAN PLANTATIONS. 
I must direct particular attention to the fact that the variation of soil, temperature, and elevation 
united (all these being of the greatest extent) did not equal the effects of the altered character of light on 
the plant, — at least if I read the indications aright. 
The first and third generations had probably an equal exposure to the sunlight and to the weather ; 
but the second generation, raised under glass* (with enfeebled actinic power in the light, and in winter a 
greatly diminished, and in summer an excessive amount of this stimulus), shows a loss of product of alkaloid 
to the extent of more than one-third, and a still further deterioration in the substitution of Cinchonicine 
for the far more useful product Cinchonidine. The loss of product in Quinine is smaller in proportion, for 
reasons that will presently be noticed. 
The plant sent to India (2 b) recovered only partially its tone of production. It was about six feet in 
height when I presented it to the Government, and it was then quite a flourishing young tree, but 
in its passage from Madras to the mountains suffered by a sunstroke, and lost all its leaves. It was with 
difficulty recovered ; but by the skill of Mr. MTvor was so entirely restored that it yielded many thousand 
young plants, and these are so constantly multiplying, that this gentleman intends to plant sixty acres with 
these alone. 
The bark of this (2 b) plant was sent home to me last summer by the Indian authorities for analysis, 
and vielded as above. 
%! 
Effect of Sunlight. 
I have before remarked a particular sensitiveness to the action of sunlight in the Cinchonas, especially 
in some of the more delicately-formed species ; and I now present my examinationf of the bark of 
C. succirubra , sent home by Mr. Thwaites from Ceylon, showing the different effect of growth in deep 
shade, in more partial, and in full sunlight. I thought this well-devised experiment worthy to be followed 
up by the most complete examination, microscopical as well as chemical, in my power. The chemical 
examination, as reported to the Government, is as under : 
No. 1. Bark of C. succirubra , taken from trees grown in the forest under dense shade. Plants planted 
out 8th February 1862, yields (1866) : — 
Sulphate of Quinine 
... 
. 1-48 
Cinchonidine . 
• 
. -61 
Cinchonine 
* 
. 2-54 
Total . 
. 4-63 
The proportion of Cinchonine (including Cinchonicine) in this sample is very remarkable. 
No. 2. Bark of C. succirubra taken from trees growing in the open garden, planted twenty-five feet 
apart, on the same day as the last. 
Sulphate of Quinine 
. 
2-35 
Quinine uncrystallized 
. . 
•95 
3-30 
Cinchonidine . 
1-11 
Cinchonine 
. 
•58 
Total 
. 4-99 
* This plant (No. 2 a), which I was obliged to cut down (January, 1866) has again (May, 1868) grown up to above seven feet 
in height, and is more vigorous than before, 
t Return, etc., p. 379. 
