APPENDIX. 
37 
The analysis was troublesome, although the hydrated alkaloids were obtained in a state more free than often from colouring 
matter. The weight of the precipitated alkaloids appeared to be 12*75 per cent., but this hopeful amount did not yield propor- 
tionate results, probably from an amount of wax and resin being carried down with the alkaloids. I obtained with difficulty a small 
crystallization of sulphate of quinine, and the remaining liquor, when precipitated, dissolved in ether, and the solution left to 
concentrate by evaporation, furnished crystals of cinchonidine adhering to the sides of the vessel, and at last uncrystallizable 
quinine containing a portion of quinidine. 
The remarkable feature was the large production of fine cinchonine, almost insoluble in ether, yielding good crystals from spirit 
of wine, and these, when formed into sulphate, giving the very characteristic salt. In all this, the root bark is decidedly superior ; 
but, it will be observed, it is cinchonine , and not quinine , that (at all events in this species) is the product of this root bark. I give 
the total as follows : — 
Quinine (as sulphate) 
,, uncrystallizable . 
Cinchonine .... 
Cinchonicine, water, and gum resin 
1*75 
4*50 (?) 
6*25 
. 3*00 
. 3*50 
12*75 
This root bark would not be 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 30th, 1868. 
The sample of No. 2 Cinchona succimibra , root ba-rk, from a tree seven years old , with your letter of the 2 1st instant, duly 
reached me, and immediately I set at 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 cultivated cinchonas. 
I found in the bark 11| 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 
consist of quinine (cry stalliz able), 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 
accompanies 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 cinchonidine. In this I was, however, frustrated, for I could not find till now 
with certainty its presence. At this moment that I write this letter my result is that the mentioned 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 
quantity, 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 18th, 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 quantity which I always use), and one of the remaining 9*5 grammes. From the first I obtained 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 imponderable trace of dark brown resinous matter remained 
undissolved. As the acetic solution proved to contain no quinidine, it was shaken with caustic soda and ether. The following day 
the etherial solution, which was lemon-coloured, was evaporated, and the residue dried at 212° F. Its amount was 0*931 gramme; 
this root bark contains, therefore, 4*774 per cent, of alkaloid soluble in ether. I obtained from these 0*931 gramme beautiful 
herapathite, but found, in the meantime, that the largest part of this alkaloid soluble in ether is not quinine , but an amorphous 
