By distilling these alcoholic solutions in a retort, until a quantity of solid matter appears on the side of the retort, and small globules of oily matter are seen rolling on the surface of the fluid, the liquid divides into two parts: a bitter milky fluid, which deposits cinchonia on cooling, in the form of impure crystals; the other a viscid substance, which contains cinchonia that may be obtained by converting it into the sulphate, and again decomposing it by lime. It may be also procured by making the decoction with water acidulated with muriatic acid, concentrating the decoction, and digesting with successive portions of slacked lime, until a decided alkaline reaction is apparent. The precipitate then collected, is to be boiled with alcohol. According to Veriton, 1.4 per cent, is obtained; or 80 grains from lb.j. of bark. The quantity of quina does not exceed 0.03. These crystals are purified by dissolving them in boiling alcohol and recrystalliz-ation. In this state the crystals are acicular and white, having an intensely bitter taste, and are scarcely soluble in water, requiring 2500 parts at 212°: neither are they very soluble in alcohol, at common temperatures, although they are very soluble in boiling alcohol. They are also soluble in ether and the fixed oils.

When heated to 450° in a glass tube, cinchonia fuses like a resin, and on increasing the heat, is decomposed, evolving ammonia, and depositing carbon. It is a compound of 77.81 of carbon, 7.33 hydrogen, 8.87 nitrogen, and 5.9 oxygen: 20 eq. carbon = 122.4 + 12 hydrogen = 12+1 nitrogen = 14.15+l oxygen = 8, making its equivalent = 156.55.

1 The great desire of our bark merchants to procure quilled bark has induced the bark gatherers often to produce this effect by heat, which always diminishes the virtue of the bark.-MSS. of Don Felix Devoti of Lima, in my possession.

2 On this account the inhabitants of Peru name it Quinacana, hairy Quina.

3 Von Bergen, Versuch einer Monographic der China, Hamburgh, 1826.

1 Annales de Chimie, lix. 116___This species is the silver Huanuco, or Lima, erroneously supposed to be the Quina provinciana, Q. Huanuco, or Q. Guanuco of the Spaniards.

2 None of the kinates can be procured directly from the bark in a crystalline form, but they may be formed by the direct combination of kinic acid with the Cinchonia or Quina; or by the decomposition of the sulphates of these alkalies by means of the kinate of lime. This kinate may be procured by evaporating an infusion of bark to an extract, then treating this with alcohol, until a viscid residue is left, which consists of mucilage and kinate of lime. If an aqueous solution of the viscid residue be made, and evaporated at a gentle heat, crystals of kinate of lime are deposited, and may be purified by a second crystallization. To obtain kinic acid, a solution of the kinate may be decomposed by oxalic acid; the acid remains in solution, and is readily obtained by crystallization, transparent and colourless.

Cinchona is also found, in small quantities, in the two other officinal species of bark. Its taste is bitter, accompanied by the flavour of the bark; it neutralizes acids, forming salts, some soluble, others insoluble in water at 60°.

Mutis and Zea regard this species of Cinchona as directly febrifuge; as chiefly applicable in intermittent fevers of long standing; and also assert, that it never fails to cut short an ague when administered at its accession.1

2. Cinchona oblongifolia. Mutis.2 Officinal. Cinchona oblongifoliae cortex, Lond. Edin. Dub.

Oblong leaved Cinchona Bark. Red Bark.

Syn. Quinquina rouge (F), Rothe Chinarinde (G.), China (I.), Quina roxa, Quina colorada (S.), Quina Vermetha (Portug.).

1 Annal, de Historia Natural, ii. 609

2 Synonymes. C magnifolia, Flor. Peruv., which is found to the south of the equator, on the mountains of Panatahuas, near Cuchero, Chinchao, and Chacahnassi. Lambert denies its affinity with magnifolia. See Illustration, etc. p. 12.; but from the specimens in my possession I cannot admit this opinion Von Bergen is of opinion that the species furnishing the red bark is not yet ascertained.

The tree yielding this bark is the largest of the genus: it is found on the Andes, growing in the woods on the banks of the mountain streams in great abundance, at Riobamba, Chinchao, Cuchero, and Chacahnassi; flowering in June and July. It was discovered by Mutis near Marimita, in 4° North lat., at an elevation of 4000 to 8500 feet. It rises to a very considerable height on a single erect, round stem, which is covered with smooth, brownish ash-coloured bark. The older branches are round, smooth, and of a rusty colour; the younger are obtusely four-cornered, leafy, and of a diluted reddish colour. The leaves are opposite, large, the full-sized ones being one or two feet in length, of an oblong oval shape, and supported on short, semi-round, purple petioles. They are entire, pale, and shining on the upper surface; on the under marked with veins that turn to a purplish colour: and at the base of each are numerous bundles of white bristles : the stipules are supra-axillary, interfoliaceous, opposite, contiguous, united at the base, and of an obovate figure.

The flowers appear in large, erect, much compounded, terminal, corymbose panicles, somewhat branched, on brachiated, many-flowered peduncles; the calyx is small, five-toothed, and of a purple colour; the corolla white and odorous, with the limb spreading, and hairy within; the filaments are very short, inserted into the tube of the corolla, supporting oblong anthers three times the length of the filaments, bifid at the base, and situated below the middle of the tube of the corolla. The capsules are large, ovate, obscurely striated, slightly curved, and crowned with the calyx.1

The tree is named in the vernacular Spanish, Palo de re-queson, and Cascarilla de flor de Azahar, from the flowers resembling in odour those of the orange. Its bark is the Quina Roxa, and has been supposed to be the Cascarilla colorada of commerce; but there is reason for thinking that this opinion is incorrect2 The bark of C. oblongifolia is certainly not the red bark known as such in this country. Von Bergen has satisfactorily proved that the bark of C. oblongifolia bears no resemblance to the ordinary red bark; and both Ruiz and Pavon acknowledge that they are ignorant of its source, but that it is very different from the red bark of Santa Fe, which is that of the C. oblongifolia, and contains little of either of the alkaloids, on which the goodness of the Cinchona barks depends. It was supposed by Condamine to be the bark of the larger branches of the same tree which yields the pale bark. The genuine red bark is brought to this country from Peru, in chests, which contain from 100 to 160 lbs. each; never in seronnes. It consists of various sized pieces, covered with a thin and rough, entire, reddish-brown epidermis, with wavy, longitudinal wrinkles, occasionally elevated into oblong warts, friable, and of a granular consistence.