CINCHONA CUPREA. © 53 
youngest bast layers that sieve-tubes and parenchyma predominate ; 
and here particularly, although also in the outer bast, crystal-cells 
(x) are present, in which finely crystallized oxalate is deposited. 
The bast shows accordingly (Plate VIII) a distinct separation into 
an outer zone, rich in sclerenchyma, and an inner parenchymatic 
zone, containing fewer fibres, and particularly a less number of 
stone cells. The medullary rays of the bast are but narrow. 
The by far predominating sclerenchyma is the cause of the 
remarkable hardness of this bark, which, therefore, in London, 
was also named “hard bark.” It is, furthermore, characterized 
by the red coloring matter, which penetrates the entire tissue so 
abundantly that it is almost impossible to decolorize it, e. g., by 
means of ammoniacal alcohol. 
The bark of the Cascarilla magnifolia, mentioned on pages 10 and 
48, agrees very nearly, in regard to its structure,* with the Cinchona 
cuprea. The cork cells of the former, however, are thin-walled, 
as in the Cinchonas, and its bast-fibres do not form such long, 
straight rows as in Cinchona cuprea, where they may be followed 
uninterruptedly from the youngest portion of the bast even into 
the outer bark. 
Hesse has shown? that in this Cinchona cuprea, which I saw for 
the first time in his collection, the same alkaloids are present as in 
the Cinchona barks. Since the Cinchona cuprea, independent of 
the other bases, affords uniformly from 1 to 2 per cent. of quinine, 
it is the more willingly worked by the manufacturers, as in conse- 
quence of the absence of cinchonidine’ the preparation of pure 
sulphate of quinine from this bark is rendered much easier. 
The tannic acid of the Cinchona cuprea, according to Hesse, is 
not the same which exists in the Cinchona barks, although the 
former likewise produces a dark green precipitate with ferric salts. 
Hlasiwetz, in 1867, ascertained that the tannic acid of coffee, by 
boiling with caustic alkali, may be’ split into sugar and caffeeic acid, 
C,H,O,, one of the hydro-cinnamic acids C,H,<Gén-co-on- Ker- 
ner, in 1882, treated an alcoholic extract of Cuprea bark in the 
same manner, supersaturated the liquid with sulphuric acid, and 
agitated it with ether, which then furnished crystals of caffeeic acid. 
The yield amounted to about ¥% per cent. of the bark employed. 
1 This is well figured in Berg's Chinarinden der pharmakognostichen Sammlung 2 
Berlin, 1865, Plate X, Fig. 27. In the innermost portion of the bast there are many 
more fibres than here—compare our Plate VIII. 5 
2 Berichte der Deutschen Chemischen Gesellschaft, 1871, p. 818. cee 
8 According to Hesse, Berichte der Deutsch Chem. Ges. 1883, pp. 59, 60, homo- — 
cinchonidine, dicinchonine, quinamine and conquinamine have also never been met 
with in cuprea bark. (F.B.P.) — me bras 
