ANALYSIS OF CHINCHONA BARK AND LEAVES. 21 
Alkaloids,"* that the Quinine and Chinchonidine salts agree closely 
among themselves, and differ widely from the Quinidine and Chinchonine 
compounds. 
I may further remark, that the Chinchona succirubra is a tree which 
varies greatly in its products in its native forests, and that the Chin- 
chona micrantha, in Bolivia, approaches to the character of a Calisaya, 
as I have noticed under that head ; its bark has a different appearance 
from that of Huanuco, and, again, this now sent home varies widely 
from either of the above. I notice, in examination, the peculiar yellow 
colouring-matter common, it seems, to all the forms of this species 
(C. micrantha), as I have before noticed. 
The Calisaya bark sent this time by Mr. M‘Ivor is, I fear, an illus- 
tration of the possibility of change in the wrong direction, as it contains 
far too large a percentage of Chinchonidine in proportion to the Quinine. 
The appearance of the bark indicates a not very vigorous growth, or, at 
all events, it differs from that it assumes in its native locality. It 
would never be recognized as the bark of Chinchona Calisaya. 
The bark of No. 6 is recognized by an experienced dealer as “ thin 
rusty crown, worth ls. 3d. to ls. 4d. per lb.” It is, I presume, the 
bark of the variety Bonplandiana, i. e. the colorada del Rey, as brought 
home by Cross; it is remarked as more red than is customary with 
rusty crown. 
As the quantity of bark in No. 1 and No. 4 was not exhausted in 
my experiments, I have returned 1000 grains of each of these, thinking 
that it would be a satisfaction to the Government to engage Dr. de Vrij, 
whose chemical skill and experience are so well known, in further re- 
searches on the subject.—1 have, etc. 
Joun Error HowaRD. 
* Dated 19th June, 1857. 
F Messrs. Jenkin and Phillips to Mr. J. E. Howard.—" 51, Lime 
Street, 21st July, 1865.— The sample of bark you left with us appears to 
thin rusty crown, worth 1s. 3d. to 1s. 4d. per lb. We thank you for the sight 
of it." 
