68 - CINCHONA BARKS. 
of which, according to Van Gorkom, is adapted for cabinet-makers’ 
work, contains, besides chinovin (see p. 61), occasionally about 1% 
per cent. of alkaloids, as stated by Bernelot Moens, in the annual 
report of the Javanese cultivation for 1880. : 
The Zeaves of the Cinchonas have an acidulous, bitter taste, and, 
after drying, an odor resembling tea. It is placed beyond doubt 
that they contain an insignificant amount of alkaloids, the prepa- 
ration of which, in a pure state, however, is attended with greater 
difficulty than from the bark. Broughton, in 1870, obtained from 
the leaves of the Indian C. succirubra, only fractions of a per mille 
of alkaloid.'. According to the experience of English physicians 
in India, which, indeed, is, as yet, not very extended, the leaves of 
C. succirubra deserve consideration as a febrifuge.* Their taste is 
due chiefly to chinovin, of which, e. g., in the last named species, 
they contain as much as 2 per cent., and in general appear to con- 
tain, on an average, more than the bark. The amount of chinovin 
stands presumably in inverse proportion to the percentage of 
alkaloids. 
Still more bitter than the leaves are the flowers, the bitterness of 
which, however, is not taken up by the aqueous infusion. Brough- 
ton, in 1869, found them to contain chinovin, but no alkaloid. 
The Cinchona fruits, which likewise have a bitter taste, contain 
either no bases, or but an extremely small amount. O. Henry, in 
1835, found none therein, as likewise DeVrij, in 1870; Broughton, 
in 1867, met with doubtful traces of alkaloids in fresh capsules. 
If quinine or cinchonine be heated with volatile organic or in- 
organic acids, or with such substances as are capable of yielding 
them, a beautiful red decomposition product is formed. Grahe, 
assistant at the laboratory of the University of Kasan, has shown 
(1858) that the same product may be very nicely obtained from 
Cinchona barks. No other bases show this behavior, and barks 
also which contain no cinchona bases do not afford this red product. 
A red tar, indeed, appears also upon heating cinchona red (in so far 
as the latter is not most carefully freed from the alkaloids?). 
Grahe's test, in combination with the simplest microscopical 
examination, therefore, affords an admirable means of furnishing 
the proof whether a bark provided with Cinchona alkaloids is at 
hand or not. By the entire absence, or extremely small percentage, 
of Cinchona bases, this reaction is not obtained, even when using 
a true Cinchona bark. Thus, e. g., with the Cinchona from Para, 
and the bark designated by Winckler? as Calebeja, which possess 
1! Blue Book, 1870, p. 238. 2 Blue Book, 1863, p. 264. 
* Compare also Wigger’s Pharmakognosie, 1857, p. 355: ‘‘clove-brown Calebeja.” 
