10 
ME, J. BEQUGHTON’S CHEMICAL AND PHYSIOLOGICAL 
thus marked, it is to be expected that their action on the growing bark produces changes 
of a similar character. Experiment shows that this is the case to a great extent. 
A method has been introduced into cinchona-cultivation by Mr. M c Xvor, Superin- 
tendent of the Government Neilgherry Plantations, which, when applied to young trees, 
produces some remarkable results. It consists in covering the bark of the trunk with a 
coating of moss. After the expiration of a year or eighteen months, the bark is found 
to be greatly improved in quality, to have become rather thicker, and to contain a larger 
general yield of alkaloids as well as an augmented proportion of quinine. In illustration 
of this I may quote the following analyses of the barks of trees of C. succirubra that 
have been thus treated : — 
No. 1. 
Bark of - 
C. succirubra 
sixteen months 
under moss. 
No. 2. 
Bark of same trees 
renewed under 
moss sixteen 
months. 
No. 3. 
Original bark. 
Total alkaloids 
10-72 
8-22 
6*7 4 per cent. 
! Quinine 
4 31 
5-14 
2-40 
Cinchonine and cinehonidine 
6-41 
3-08 
4-34 
Total sulphates obtained crystallized 
9-27 
4*67 
6-OG „ 
Sulphate of quinine 
4-02 
3-87 
2-21 
„ cinehonidine 
5-25 
0-80 
3-85 
From certain observations I had made on the difference in the barks of trees grown in 
shade and sunshine, and the known changes produced by the latter both on the alka- 
loids and barks, I was led to believe that the singular improvement in quality pro- 
duced by mossing the bark was the effect of shielding it from the prejudicial action of 
the sun’s rays, whether acting directly or indirectly. In order to test the truth of this 
by experiment, I covered the trunk-bark of two trees of C. succirubra, one with a shield 
of tin plate, and the other with a double fold of black alpaca cloth. The effect of this 
would be to keep the bark in darkness, while the access of air was not impeded. After 
ten months’ protection analyses were made, and the following Table expresses the results. 
Tree covered with tin plates. 
Tree covered with black cloth. 
Original bark. 
Bark after 
ten months’ 
protection. 
Original bark. 
Bark after 
six months’ 
protection. 
Bark after 
ten months’ 
protection. 
Total alkaloids 
5-29 
8-10 
5-04 
6-91 
7-92 
Quinine 
2-16 
T6o 
2-26 
2*03 
2-34 
Cinehonidine and cinchonine 
3-13 
6-45 
2-78 
4-88 
5-58 
The protection from light has thus, in the otherwise dissimilar instances, had the 
effect of greatly increasing the amount of alkaloids. It is remarkable, however, that 
the quinine has not shared in the increase, a consequence I was not prepared to find, 
