28 
QUIXOLOGY OF THE EAST INDIAN PLANTATIONS. 
manifestation of a pink colour, which, combining with excess of lime, forms a pink lake. When the 
filtered solution is precipitated bp hydrochloric acid, a separation of Kinova-bitter takes place, with its usual 
appearance, and apparently almost milk-white. When this is collected, however, and again acted on by 
lime, a pink lake, but of a fainter hue, is again formed, and so on for several repetitions before the pro- 
duct which I have mentioned is obtained pure, and free from colour. 
I wish it to be understood that I do not assert the homogeneity of this mother-substance, nor suppose 
that it can be recognized as a chemically pure body , but I like to follow Nature in her operations, and to 
study the becoming as well as the being of her products. 
The pure kinovic acid is easily obtained from kinova-bitter. If the Mother-substance is mixed with an 
ethereal solution of Quinine, a combination takes place which I have described as Kinovate of Quinine, 
and have represented the crystals it forms.* Prom this combination there seems to be a slow separation 
of Cinchona-red, as happens with lime above. I have no doubt that this is the state of combination in 
which the alkaloids exist, more especially in the Red Bark. It is this which explains the reason why 
aqueous infusions of Red Bark are deficient in strength, which is not so much the case when they are made 
from barks in which the alkaloids are united to kinic acid. It is, moreover, as I have before explained, 
chiefly this curious state of combination which renders the extraction of the alkaloids a matter of so much 
.difficulty. The attempt to manufacture sulphate of Quinine on the spot where the trees are found has 
always failed (though often attempted in South America), and equally profitless has been the attempt to 
precipitate the alkaloids and send them over mixed with lime ; — in this last case also other deteriorating 
effects were produced. Spirituous tinctures dissolve more of the alkaloids, but also of partially oxidized 
Cinchona-red, which gradually separates by slow oxidation. 
The Mother-substance of the Cascurilla. 
I am indebted to Senor Pedro Rada for specimens of the Mula Cascarilla or Cascarilla Carua of 
Weddell, consisting of leafy branches with very fine leaves of some 18 inches long, and also of sections of 
branches covered with bark. I was thus enabled to examine the wood in reference to its constituents as 
compared with that of the Cinchona. A peculiar colouring matter is very abundant in this Cascarilla, so 
as to form apparently a dark purple or almost black incrustation on the external portion of the bark. It is, 
therefore, to be expected that some analogous mother-substance should exist in the wood. This I found to 
be the case, for in treating the wood, rasped to a fine powder, with ether, and evaporating, I obtained a 
lemon-coloured, resinous-looking substance, similar in some of its properties to that of the Cinchona. The 
ethereal solution, treated with lime, gave a deposit of what might be called Cascarilla-red, and, when shaken 
up with caustic or with liquor ammonim, a fine, rich, characteristic colour was developed in the solution, 
and the supernatant ethereal solution became partly filled with crystals, the precise nature of which I could 
not determine. On the whole, the great contrast between the colouring matter in these allied genera seems 
to be that in the Cinchona the mother-substance is very sternly oxidized in connection with the formation of 
the alkaloids ; but in the Cascarilla the process is more rapid, and perhaps more complete. 
When the wood is treated with milk of lime, a considerable amount of kinova-bitter is obtained by the 
addition of acid to the filtered solution. 
Products of the Cells. 
It will be observed that none of the substances I have noticed are nitrogenized bodies nor capable of 
acting powerfully on the human frame. The additional step to the formation of alkaloid from these, I 
* 
suppose to be taken in the cells of the bark, commencing more especially with the cambium. I have 
* f Microscopical Observations/ pi. ii. fig. 12 b . 
