212 ANALYSIS OF CHINCHONA BARK AND LEAVES. 
I must remark that the commercial value of specimens of bark in- 
tended for the manufacturers of sulphate of quinine can never be ascer- 
tained by the mere knowledge of the percentage of alkaloid soluble in 
ether, since it is necessary that this should be shown to exist in such 
a state as to crystallize with acids into the required compounds. 
In the case of No. 1, the bark from the thickest part of the lower 
branches of a C. succirubra, two years and five months old, this exami- 
nation was most satisfactory, confirming that which I stated in my first 
report as to the facility with which the alkaloids were obtained in a 
state of purity, although the amount of red colouring matter in the 
bark is very great. The amount of purified alkaloids T estimate at 6 
r cent., consisting of Quinine 3:14, Chinchonidine 2-06, Chincho- 
nine 0:80. This large product of alkaloids might probably be still further 
increased by surrounding the stem with moss, in the manner in which 
Mr. M‘Ivor has so happily suggested, since Dr. de Vry found 8:409 per 
cent. of alkaloids in a stem which had been so treated. It seems to 
me, from this trial, that the East Indian bark, the produce of C. succi- 
rubra, will rival in price the Bolivian Calisaya, which is by no means the 
case with the bark of the branches of the C. succirubra as grown in 
South America. It is important to remark that the very high price of 
between 85. and 9s., which has quite recently been paid for red bark 
in this market, applies only to those pieces of bark from the trunk of 
the tree which possess, from their age, a peculiarly bright-red appear- 
ance. I have forwarded a small phial with commercial Sulphate of 
Quinine obtained from this No. 1, as also Sulphate of Chinchonidine 
separated from the above. T have only to remark further on this bark 
that its appearance bespeaks its good quality, and that there can be no 
doubt the season chosen (24th of February) is most favourable to its 
being well seeured. 
Of No. 2 I cannot speak so favourably. This consists of the very 
minute bark from the spray or small portions of the same branches 
as No. 1. From this I did not succeed in obtaining more than 0'9 
per cent. of impure alkaloid, which lost one-half in the attempt to 
purify, since the alkaloids are much implicated with tannin (apparently), 
and not capable of easy crystallization. I would suggest that the best 
destination for the bark of these small branches might probably be to 
sell it to the druggist for pharmaceutical preparations, for which pur- 
* Forming a resinous hydriodate. 
