EXPERIMENTS ON LIVING CINCHONA. 
11 
and for which. I can only partially account. An experiment made in the warmer climate 
of Wynaad, in which the bark was shielded with thick coarse woollen cloth, produced 
similar results to the above, in which an increase of quinine was also obtained. Hence 
it seems demonstrated by these experiments that, even while the bark is growing, there 
is a constant deterioration and waste going on by the action of the sun’s rays, which is 
prevented by removing the cause. Whether it is the light of the sunshine which pro- 
duces the effect, or the comparatively high temperature produced in the outer cellular 
portions where the alkaloids are mainly situated, is a point still to be determined. 
A study of the differences in the amounts of the respective alkaloids found in the 
barks grown at different elevations appears to throw some light on the effects of tem- 
perature. A series of trees was chosen of as nearly the same age as possible, and grow- 
ing on soil of the same character, but growing at very various elevations, and hence 
under climates of very various annual mean temperatures. The trunk-bark of these 
trees was collected and analyzed. This was done at a time of the year when the yield 
of alkaloids is nearly at a minimum ; there is, however, no reason for supposing this 
circumstance would alter the comparative value of the results. The following tabular 
statements express the results : — 
Red Bark. 
I. 
II. 
III. 
IV. 
Y. 
VI. 
VII. 
7770 ft. 
7660 ft. 
7450 ft. 
6560 ft. 
5450 ft. 
3500 ft. 
2300 ft. 
Total alkaloids 
2-38 
2-03 
4-21 
5*75 
3-8 
4-10 
4-1 
Quinine 
0-45 
0-33 
0-70 
2-50 
1-2 
0'S6 
0-6 
Cinchonidine and cinchonine 
1-93 
1-70 
3-51 
3-25 
2-6 
3-24 
3*5 
Crystalline sulphates obtained 
1-75 
1-60 
3-20 
4-20 
3-1 
3-58 
3-4 
Crown Bark. 
I. 
II. 
III. 
IV. 
8000 ft. 
7770 ft. 
6007 ft. 
5450 ft. 
Total alkaloids 
3-42 
3-61 
3-10 
2-68 
Quinine 
2-10 
1-83 
0-75 
0-45 
Cinchonidine and cinchonine 
1-32 
1-78 
2-35 
2-23 
Crystalline sulphates obtained 
3-20 
3-30 
2-60 
1-80 
The analyses in the first Table were made with the product of trees which, on account 
of the comparatively cold climate, were stunted and unhealthy in appearance, and thus 
are scarcely fit subjects for the inquiry. Analyses IV., V., A 7 !., VII. agree in showing 
that from a certain point an increase of mean temperature has the effect in diminishing 
the amount of quinine, and to a less marked extent the total alkaloids. The same effect 
c 2 
