Cinchona. - The bark of Cinchona Calisaya Weddell, Cinchona officinalis Linne and of hybrids of these and of other species of Cinchona (nat. ord. Rubiaceae), yielding, when assayed, not less than 5 per cent. of total alkaloids, and at least 2.5 per cent. of Quinine (C20H24N2O2+H2O=341.3).


South America, on the Eastern slope of the central chain of the Andes, thence spreading northward into Colombia; cultivated in Java, India, Jamaica, and other countries; to a limited extent also in South America.


In quills or in curved pieces, varying in length, and usually 2 or 3, or sometimes 5 mm. thick; the outer surface covered with a gray or brownish-gray cork, usually slightly wrinkled, marked with transverse, and also with intersecting, longitudinal fissures ( C. Calisaya), and sometimes with scattered warts and slight longitudinal ridges; inner surface light cinnamon-brown, very finely striate; fracture short and granular in the outer layer, and finely fibrous in the inner layer; powder light brown or yellowish brown; odor slight, somewhat aromatic; taste bitter and somewhat astringent.


The chief constituents of Cinchona Bark are five alkaloids, two acids, a glucoside, Tannic acid, a coloring matter and a volatile oil.

(1) Quinine. - An Alkaloid, exists as the Hydrate. Gives a green color with Chlorine water and Ammonia; turns the plane of polarization to the left, solutions of its salts are fluorescent. Forms salts with acids. (See p. 464.)

(2) Quinidine. - An Alkaloid, C20H24N2O2, isomeric with Quinine, differing from it only in crystallizing in prisms, turning the plane of polarization to the right, and not being soluble in ammonia except in excess.

(3) Cinchonine. - An Alkaloid. C20H24N2O. Colorless prisms, inodorous, bitter. No green color with Chlorine water and Ammonia. Turns the plane of polarization to the right. Not fluorescent. (See p. 466.)

(4) Cinchonidine. - An Alkaloid, C19H22N2O, isomeric with Cinchonine, differing from it in turning the plane of polarization to the left, being sparingly soluble in Ether, and being slightly fluorescent.

(5) Quinamine. - An Alkaloid C19H24N2O2. Not important.

(6) Kinic or Quinic Acid. - C7H12O6. Large, colorless prisms. It and its salts are soluble in water, and thus Quinine may be given subcutaneously as Quinine Quinate. This acid is found in the Coffee Bean and other plants. It is allied to Benzoic Acid, and appears in the urine as Hippuric Acid.

(7) Kinovic or Quinovic Acid, C32H48O6. - A white amorphous substance related to Kinovin.

(8) Kinovin or Quinovin. - A Glucoside, C30H48O8, which easily decomposes into Glucose and Kinovic Acid.

(9) Cinehotannic Acid. - 2 to 4 percent. It is the astringent principle of Cinchona Bark. It differs from Tannic Acid in becoming green with ferric salts. It is easily oxidized to Cinchona Red.

(10) Cinchona Red. - The coloring matter of the bark. It is almost insoluble in water.

(11) A Volatile Oil. - This exists in minute quantities. Cinchona Bark owes its smell to it.

Remijia Bark yields, in addition, Homoquinine, which is a compound of Quinine and another alkaloid, Cupreine, C19H22N2O2.


Inferior barks, known by their not yielding the full strength of Quinine and Cinchonine.

The true yellow Cinchona Bark must not be confounded with other Cinchona Barks of a similar color, but having the bast fibres in bundles or raised rows, and breaking with a splintery or coarsely fibrous fracture.

Incompatible. - Ammonia, lime water, metallic salts and gelatin.

Dose, 10 to 60 gr.; .60 to 4.00 gm.


1. Infusum Cinchonae. - Infusion of Cinchona. Cinchona, 60; Aromatic Sulphuric Acid, 10; by percolation with Water to 1000. Dose, 1 to 2 fl. oz.; 30. to 60. c.c.

2. Extractum Cinchonae. - Extract of Cinchona. By maceration and percolation with Alcohol and Water, distillation of the Alcohol and evaporation.

Dose, 4 to 30 gr.; .30 to 2.00 gm.

3. Extractum Cinchonae Fluidum. - Fluid Extract of Cinchona. By maceration and percolation with Alcohol, Glycerin and Water, and evaporation, addition of Alcohol.

Dose, 10 to 60 m.; .60 to 4.00 c.c.

4. Tinctura Cinchonae. - Tincture of Cinchona. Cinchona, 200; Glycerin, 75. By maceration and percolation with Alcohol and Water to 1000.

Dose, 1/2 to 2 fl. dr.; 2. to 8. c.c.