THE EIGHTH REMITTANCE OF BARK FROM INDIA. 
319 
Quinine (as sulphate).1*75 
„ uncrystallizable .... 4 - 50 (?) 
- 625 
Cinchonine.3 00 
Cinchonicine, water, and gum resin . . . 3‘50 
12-75 
This root hark would not he of more value than that mentioned above (of the 
C. Josephiana ) unless it were wanted for the extraction of cinchonine. 
No. 3. I shall transmit the report of the analysis when I receive it from Dr. de Vrij. 
No. 4 consists of four pieces of fine-looking crown bark, apparently not intended for 
chemical analysis. 
Nos. 5, 6, and 7 are interesting to me, and will, I hope, furnish some facts for a work 
which I am publishing, ‘ On the Quinology of the East Indian Plantations.’ They 
appear to be intended rather for microscopical examination than for chemical analysis. 
The seeds of No. 7 have been sent to Kew. 
I beg to remain, yours very truly, 
John Eliot Howard. 
SUPPLEMENT. 
Copy of a Letter from Dr. de Vrij to J. E. Howard, Esq., containing Analysis of 
No. 2 Root Bark. 
The Hague, August 30 th, 1868. 
The sample of No. 2, Cinchona succirubra, root bark, from a tree seven years old, with 
your letter of the 21st instant, duly reached me, and immediately I have set to work to 
analyse this bark, which was very welcome to me, particularly because now you have 
the opportunity to judge by yourself of the richness of the root bark, at least, of the cul¬ 
tivated cinchonas. 
I found in the bark 111 per cent, of alkaloids and 0 467 per cent, of cinchona bitter 
(kinovic acid). The part of the alkaloids soluble in ether amounts to 4'31 per cent, of 
the bark. Although these 4’31 per cent, are soluble in ether, they do not entirely con¬ 
sist of quinine (crystallizable), but contain another alkaloid also soluble in ether. As 
you expressed your wish to obtain the results of my experiments within about ten days, 
I have not been able to ascertain with certainty which is this alkaloid which accompa¬ 
nies the crystallizable quinine in its etherial solution. I suspect it is the amorphous 
alkaloid which I always find in the Indian barks, but am not yet quite sure of it. I 
obtained beautiful herapathite from the part of the alkaloids dissolved by ether, so that 
there is no doubt that this root bark contains really crystallizable quinine. In treating 
the total amount of alkaloid with ether, I had some reason to expect to obtain also cin- 
chonidine. In this I was, however, frustrated, for I could not find till now with cer¬ 
tainty its presence. At this moment that I write this letter my result is that the men¬ 
tioned bark is rich in alkaloids, of which the part insoluble in ether consists chiefly of 
cinchonine. If cinchonidine is perhaps also present, it can only be a very small quan¬ 
tity, not to be compared with the large quantity which I obtained from the stem bark 
of C. succirubra. 
Copy of a Letter from Dr. de Vrij to J. E. Howard, Esq., containing Analysis of 
No. 3 Root Bark. 
September 18 th, 1868. 
Together with your valued letter of September 3rd I received the No. 3 of root bark 
from C. succirubra. ... As the amount of the powdered bark dried at 212° F. was only 
19 - 5 grammes, I divided this quantity into two parts, viz. one of 10 grammes (the quan¬ 
tity which I always use), and one of the remaining 9-5 grammes. From the first I ob¬ 
tained 1-202 grammes, and from the second 1 088 grammes of alkaloids. The average 
percentage of alkaloids in this red bark is therefore 11-743 per cent., whilst the amount 
of kinovic acid is 0 676 per cent. The combined amount of the obtained alkaloids, viz. 
2-29 grammes, was dissolved in dilute acetic acid, by which treatment only an impon¬ 
derable trace of dark brown resinous matter remained undissolved. As the acetic solu¬ 
tion proved to contain no quinidine, it was shaken with caustic soda and ether. The 
