Cinchona officinalis L (Peruvian bark), Rubiaceae ... - AaronsWorld

great care is exercised in the cultivation. The trees are allowed to reach the age of twelve years before
the bark is collected. The cultivation is largely confined to the variety Ledgeriana. Over 500,000
pounds are collected annually from Java plantations.
DESCRIPTION.In quills or curved pieces of variable size, usually 2 or 3, sometimes 5 mm. thick;
externally gray, rarely brownish-gray, with numerous intersecting transverse and longitudinal fissures,
having nearly vertical sides; the outer bark may be wanting, the color externally being then cinnamon
brown; the inner surface light cinnamon brown, finely striate; fracture of the outer bark short and
granular, of the inner finely splintery; powder light brown or yellowish-brown; odor slight, aromatic;
taste bitter and somewhat astringent.
MICROSCOPICAL.The calisaya (variety Micrantha) transversely shows milk-vessels in the cortical
parenchyma and absence of stone cells, which are present in Lancifolia. The rays of the woody
portion are more elongated and the medullary rays larger in size. Bast fibers comparatively small and
less numerous, but are spindle-shaped, as they are in all true cinchona barks showing longitudinal
section. In C. rubra the stone cells and milk-ducts are both wanting, while the bast fibers are more
numerous and stouter. The bark is richer in coloring matter. In cuprea bark the cork cells are thicker
and the cortical parenchyma cells smaller, stone cells present, milk-ducts absent, few bast fibers, but
the woody portion contains indurated cells, which simulate them. The ligneous cells are very numerous
and extend even down into the medulla. They are smaller than the bast fibers of true cinchona
barks, but much more numerous.
These barks are thoroughly saturated with pigments, principally cinchona red, the phlobaphen
of all cinchona barks. Before microscopical examination these pigments must be removed by a weak
alcoholic solution of ammonia. This requires considerable practice (Dohme). Compared with other
barks, the fibers of the liber of cinchona are shorter and more loosely arranged, being for the most
part separated into simple fibers imbedded in the bast parenchyma, or united into very short bundles.
Grahe’s test for the distinction of cinchona bark is as follows: On heating about 0.1 Gm. (1.5 gr.) of
the powdered bark in a dry test-tube a tarry distillate of a red color is obtained.
Powder.Microscopical elements of: See Part iv, Chap. I, B.
OFFICIAL PREPARATIONS.
Fl. Ext. Cinchonae, Dose: 15 drops (1 mil).
Tr. Cinchonae , 1 fl. dr. (4 mils).
532a. CINCHONA RUBRA.The dried bark of Cinchona Succirubra Pavon (more) or its hybrids,
yielding not less than 6 per cent. of the total alkaloids of Cinchona. ”In quills or incurved pieces,
varying in length, and from 2 to 4 or 5 mm (1/12 to 1/6 or 1/5 in.) thick; the outer surface covered
with a grayish-brown cork, more or less rough from warts and longitudinal, warty ridges, and from
few, mostly short and not frequently intersected transverse fissures, having their sides sloping; inner
surface more or less deep reddish-brown and distinctly striate; fracture short, fibrous in the inner layer;
outer layer, granular. For years practically all of the red cinchona bark, so called, was only a hybrid, but
recently, and especially for a year past, fine quill bark of pure succirubra has frequently been received.
Powder.Microscopical elements of: See Part iv, Chap. I, B.
CONSTITUENTS.Upon quinine, C20H24N2O23H2O, the bark almost exclusively depends for its
value. This alkaloid is colorless, amorphous, or in acicular crystals; inodorous, very bitter; soluble in
1670 parts water, 6 parts alcohol, 26 parts ether. Aqueous solutions of the salts have a blue fluorescence,
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