16 
QUINQLOGY OF TIIE EAST INDIAN PLANTATIONS. 
It will be seen that this amount (= 045) coincides almost exactly with the product obtained from the wood 
of the roots, which I have given above as Quinine and Cinchonidine, 041 ; and Cinchonicine, 005 ; together, 0\46. 
The increase in alkaloid in the bark of the larger branches of the same tree (sent as No. 1) was remarkable. These 
gave, of purified alkaloids, per cent. — 
Quinine . . . .3-14 
Cinchonidine . . . 2-06 
Cinchonine . . . (>80 
6-00 
I think I may fairly consider that in this latter case of the larger branches the descending sap must 
have come into play, together with the cell-formation of the cambium, as elsewhere described. 
The Alkaloids formed in the Bark. 
We have thus far traced the deposits of the ascending sap in its course from the roots, through the 
w r ood, to the leaves; and we do not find any reason to look upon either the wood of the roots, or of the 
stem, or of the more succulent and recently-formed portions of the ligneous structure as the seat of the 
formation of the alkaloids. In all these parts the proportion of alkaloid is insignificant when compared 
with that of the bark. In the root-wood, moreover, it is found in such a state as would naturally follow 
from its being deposited there (as combined with resin, which is a secondary and not a primary product of 
vegetation) after its downward course, such as I have described,* is completed, and then carried laterally 
from the root-bark by the medullary rays into the root-wood. In the outside portion of the stem-wood we 
find rather less alkaloid and rather more kinovic acid than in the centre-wood, and there is a smaller 
amount of resin, but a perhaps larger proportion of waxf associated with the alkaloids : they exist, in 
both, in a somewhat greater degree of purity than in the root. 
When we come to the leaves, we find almost the same proportion of alkaloid as in the wood, but this 
amount not increased, as would surely be the case if the leaves were the seat of its formation. Nothing 
seems changed, except that here we find (as also in the very young wood) the presence of chlorophyll, which 
in the descent of the sap, appears gradually to degenerate in the bark of the small twigs into, or else to 
become mixed with, a tannin substance, and this again into resin. In tracing the course of the nourishing 
or descending sap, we find the alkaloids increasing greatly — not less than ten- or twentyfold, often much 
more — in their relative amount in the liber, as compared with the parts we have passed under review ; 
and what is also very important, they are in a state of much greater purity, as if freshly formed. In the 
cellular envelope there is again a considerable increase, to the extent of 100 or 150 per cent, on the 
contents of the liber, and the alkaloids, or at least Quinine and Cinchonidine appear to be especially stored 
up in this cellular envelope, but this in connection ordinarily with various substances difficult to separate 
from them. In the mossed barks, and also, according to Dr. De Vrij, in the root-bark of the young 
plants of C. Pahudiana , from some cause— possibly from the absence of sunlight — the alkaloids seem to exist 
in the cellular envelope in a state of greater purity. 
The review of the whole seems to point to the bark as the seat of the formation of the alkaloid. 
In my ‘ Illustrations of the Nueva Quinologia I gave it as my opinion that the alkaloids were 
gradually formed, chiefly in the bark itself, and to this view (founded on practical observation of the 
increase of the proportion of alkaloid in the increasingly developed bark) I now return as the result of the 
more extended researches in the present volume. 
* Illustr. Nuev. Quin. Microscop. Obs. p. 2. f Cerotic acid (saponifying with alkalies). 
J f Microscopical Observations/ p. 2. 
