REPORT ON CHINCHONA SUCCIRUBRA. 
75 
is a continual process of deterioration* of these after a certain period of the history of 
he hark, which is connected with the oxidation of the red colouring matter, and the 
production, in very old trees, of those fine descriptions of bright red bark which command 
indeed a high price in the market (as much at the present time as eight shillings per 
pound), but which would not, in many cases, be more valuable for the production of 
Quinine than bark of one year’s growth. 
I next examined the younger bark of one year’s growth, taking care to select the 
most mature portion, and found that it yielded 2\59 of alkaloid, of which 2'55 (soluble 
in ether) appeared to be Quinine and Chinchonidine, and in part crystallized into toler¬ 
ably white sulphate, which showed perhaps a rather larger proportion of Chinchonidine 
than in the older bark. On the other hand, the proportion of Chinchonine seemed 
notably less, viz. only 0 04 per cent.; but it is possible that the separation was not 
exactly effected between the Chinchonine and Chinchonidine, which is not easily accom¬ 
plished by ether in such small portions. 
The above result induced me to pay further attention to the leaves, concerning which 
the absence of any carmine sublimate by heat led me at first to an unfavourable con¬ 
clusion. The decoctions and infusions made by Mr. MTvor, though in perfectly good 
condition, showed that the contents changed most rapidly under the influence of the 
oxygeu of the atmosphere as soon as ammonia was added to the, at first, decidedly acid 
liquor. Fortunately, a good supply of several ounces of dried leaves had been sent over, 
and from these I succeeded in obtaining Quinine, though in very small quantity, but 
presenting its usual characteristics, dissolving iu acids and precipitated by alkalis as a 
whitish hydrate, soluble in ether, and left by this on evaporation as a resinous-looking 
body, having the usual bitter taste, also crystallizing not only as a sulphate, but as an 
oxalate of Quinine (the latter being the more critical test); but nevertheless presenting a 
characteristic implication with resinous or extractive matter, such as is usually met with 
in the very smallest quills or canutillos of South American bark, in analysing which it is 
frequently difficult to purify the Quinine from this adhesion. I obtained first from these 
leaves to the extent of 0T1 of alkaloid, of which part was soluble in ether, the remainder 
in spirits of wine, and afterwards 0T9 of precipitate still more combined with astringent 
matter. From these data, it seems to follow that the leaves will not supply a material for 
the extraction of Quinine, but that they will, nevertheless, be very useful when used 
fresh or in recently prepared decoction or infusion for the cure of the fevers of the country. 
To this end, the abundance of kinovic acid they contain, equal (weighed in the rough 
state) to 4-20 per cent., may also conduce. 
I have not much to remark as to the No. 3 (bark renewed over spaces previously cut), 
as the quantity sent was too small for much chemical examination, but I obtained 
abundantly by heat the crimson sublimate which marks the presence of alkaloids, and 
the promise from the external characteristics was good. The No. 4 (bark covered 
up with moss for some months) seems to me a successful experiment of Mr. MTvor’s, 
especially since I notice very abundantly in this bark the crystals of kinovate of Quinine, 
which I have described! as I found them in the “red bark” of South America, and now 
find again, quite as plentifully, in the older bark sent from India. I may add that 
generally speaking, the structure of the barks, as shown by the microscope, ^hakes it 
evident that the plants had grown vigorously and under circumstances favourable to 
their full development. 
I reserve any opinion as to the best method of drying the bark, to which Mr. MTvor 
alludes, till I have had the opportunity of examining further specimens. 
I have the honour to be, Sir, your obedient servant, 
June , 1863. John Eliot Howard. 
QUININE, CHINCHONIDINE, AND CHINCHONINE, IN THE LEAVES OF 
CHIN CB ON A SUC CHi UBRA . 
A few remarks of a technically scientific nature on some points which struck my at¬ 
tention in making the investigation detailed in my official report on the red bark grown 
in South India, may not be unacceptable. The discovery of Quiniue, Chinchonidine, 
* Described in my ‘Illustrations of Nueva Quinologia,’ uuder head C. sxiccirubra, p. 14. 
f ‘Illustrations of Nueva Quinologia,’ Mic. Obs., p. 7. 
