(Cortex.) The varieties of Cinchona Bark are obtained from different species of Cinchona. Nat. Ord. Cinchonaceae. Linn. Syst. Pentandria Monogynia.

* Med. Gazette, March 20th, 1845, p. 787.

Dublin Quart Joum. of Med. Feb. 1852, p. 250.

Cited in U.S. Disp., p. 1392. § Gaz. Hebd. de Med., Jan. 7th, 1857

The Officinal Cinchona Barks are: -

1. Cinchona Flava

Yellow Cinchona Bark. Obtained from Cinchona calisaya. Hab. Bolivia and Southern Peru. Chief active principle, Quinine. 100 grs. should yield not less than 2 grs. of Quinine.

2. Cinchona Pallida

Pale Cinchona Bark. Obtained from C. condaminea. Hab. Loxa in Ecuador. Chief active principle, Cinchonine. 200 grs. should yield not less than 2 grs. of alkaloids.

3. Cinchona Rubra

Red Cinchona Bark. Obtained from C. succirubra. Hab. The western slopes of Chimborazo. Active principles, Quinine and Cinchonine, in about equal proportions. 100 grs. should yield not less than 2 grs. of alkaloids.

Other varieties: -

Fibrous Carthagena Bark. Spongy, or Orange Carthagena, or Bogota Bark. Obtained from C. condaminea (var. δ lancifolia). Hab. Near Bogota in New Granada. Active principles, Quinine, much Quinidine, some Cinchonine. Cinchona Cinerea. Silver, grey, or Huanuco Bark. Formerly officinal in the Edin. and Dub. Pharm. Obtained from C. micrantha and C. nitida. Hab. Cuchero and Huanuco in Northern Peru. Active principles, Quinine, Quinidine, and Cinchonine. Attempts are being made to cultivate the more valuable species of Cinchona plants in India, Ceylon, Java, Jamaica, and Trinidad. The Acids of the Cinchona barks are the Quinic or Kinic, the Cincho-tannic, the Red Cinchonic, and the Kinovic. The alkaloids are Quinia or Quinine, Cinchonia or Cinchonine, Quini-dina or Quinidine, and Cinchonidina or Cinchonidine.

Med. Prop. and Action. All the varieties of Cinchona are tonic, astringent, and anti-periodic, and are, of all medicines of their class, the most powerful and uniform in their action. They owe their astringency to the presence of Cincho-tannic and red Cinchonic Acids. Their tonic and anti-periodic properties are due to the alkaloids in which they abound. Peculiarity in the action of the different kinds of bark depends on the proportion in which the alkaloids are present in them. From the large quantity which is required to be taken to obtain the full effect, and from the extremely nauseous taste, there are many persons who are unable to take Cinchona, without its causing derangement of the stomach, vomiting, headache, and in most cases, constipation, in consequence of the Cinchc-tannic and red Cinchonic Adds which it contains. These ill effects may, in a great measure, be obviated by administering its alkaloids, Quinine or Cinchonine; from both of which, as a rule, all the benefit (with the exception of the astringent effect) which is to be expected from Cinchona may be obtained, without its disadvantages. Occasionally, however, it happens that where the alkaloids fail to effect a cure, Cinchona in substance is successful In small doses bark improves the appetite, and the general tone of the muscular and circulating systems. It checks colliquative sweating in cases of extreme debility. Its action on the nervous system is shown by its extraordinary power in arresting diseases of a periodic character. In the treatment of intermittent fevers, it may either be given in a large dose shortly before the recurrence of the paroxysm, or in smaller repeated doses during the intervals. The efficacy of the infusion or decoction is greatly increased by the addition of a few drops of dilute Sulphuric Acid. (See also QuiniAe Sclphas.) Externally applied bark is an astringent and antiseptic. It is sometimes sprinkled on the surface of unhealthy ulcers. The infusion or decoction, with the addition of a mineral acid, forms a valuable gargle in putrid sore throat. Powdered bark is useful as a dentifrice in spongy conditions of the gums. Offic. Prep. of Cinchona Cava: -

1. Quiniae Sulphas (See Art

Quinia).

2. Decoctum Cinchonas Flavae (Yellow Bark In Coarse Powder Oz

j.; Dis-till'-rt Water Oj.; boil for ten minutes and strain through, calico. Sufficient Distilled Water to be added to make fl. oz. xvj.). Dose, fl. oz. j. - fl. oz. ij.

3. Extractum Cinchonae Flavae Liquidum (Yellow Cinchona Bark In Coarse Powder Lb

j.; Distilled Water q. s.; Rect. Sp. fl. oz. j. Prepared by maceration, percolation, and evaporation). Sp. Gr. about 1 100; fl. oz. iv. represent lb. j. of bark. Dose, ex. - fl.drm.j.

4. Infusum Cinchonas Flavae (Yellow Cinchona Bark In Coarse Powder Oz

ss.; Boiling Distilled Water fl. oz. x.). Dose, fl. oz. j. - fl. oz. ij.

5. Tinctura Cinchonas Flavae (Yellow Cinchona In Coarse Powder Oz

iv.; Proof Spirit Oj. Prepared by maceration and percolation). Dose, fl. drm. j. - fl. drs. ij.

Of Cinchona Pallida: - Tinctura Cinchonas Composita (pale Cinchona Bark in coarse powder oz. ij.; Bitter Orange Peel oz. j.; Serpentary oz. ss.; Saffron grs. lx.: Cochineal in powder grs. xxx.; Proof Spirit Oj. Prepared by maceration and percolation). Dose, fl. drm. j. - fl. drs. ij. Dose of either of the Cinchona Barks, gr. x. - gr. lx., or more. Incompatibles. Tartar Emetic; the salts of Iron, Lead, and Silver; all infusions containing Tannic Acid or Gelatine; and Liq. Arsenicalis.

Therapeutic Uses are considered at length under QuiniAe Disul-phas (which see).