- Origin. - Prepared from cinchonine or quinine by distillation, or obtained synthetically.

Description and Properties. - A colorless liquid, with an aromatic, pungent odor; slightly soluble in water, freely soluble in alcohol.

Quinoline itself was at one time used as a substitute for quinine to reduce temperature, but it induces collapse and has been discarded.

Analgine, ana/gen, ethoxyacetylamidoquinolin, is occasionally used. It is broken down into benzoic acid, quinoline, and an orange-colored antiseptic derivative, thus staining the urine red. It is of some service in acute articular rheumatism in doses of 15 - 30 grains (1.0 - 2.0 Gm.).

Dose. - 3-10 minims (0.18-0.6 Cc).

Chinolin Tartras - Chinolin Tartratis - Chinolin Tartrate. - Soluble in 70 or 80 parts of water. Dose, 5-15 grains (0.3-1.0 Gm.).

Quinetum - Quineti - Quinetum. - A mixture of the alkaloids precipitated by an alkali. Dose, 1-60 grains (0.06-4.0 Gm.).

Quinlnae Hydrochloras Carbamidata - Quininae Hydrochloratis Carbami-datae. - Double salt of quinine and urea. Soluble in water. Dose, 1-10 grains (0.06-0.6 Gm.). Usually employed hvpodermically.

Kairine (C9H9(OH)N - C2H6) and Thalline'(C9H9(OCH3)NH) were at one time extensively used as antipyretics and analgesics, but they have been found very depressing, and after the initial fall in temperature it has been found to rise again.

Euquinine, an ethyl carbonate of quinine, has an action precisely similar to that of quinine as it breaks down into that body. It has no advantages, save those of taste and more ready solubility.

The name cinchona given to Peruvian bark was accorded in honor of the countess of Chinchon, cured of tertian fever by the use of the drug, as early as the seventeenth century, the Spanish conquerors of the country having discerned the curative properties of the plant which scientific investigation has rendered invaluable as a therapeutic agent.

About the middle of the seventeenth century a large quantity of the bark received from America reawakened a discussion, and finally a council of Jesuits held at Rome approved a distribution of the drug - called therefrom "Jesuits' bark." It quickly found its way to other parts of the Continent and to England; yet still the opposition to its use was pronounced, and it was only when an English quack doctor succeeded in effecting cures among persons of rank by an employment of the drug that its services became general in malarial and typhoid fevers, as well as in various other diseases.

The discovery of the active principles of cinchona, crudely established by Duncan in 1803, was perfected by Pelletier and Cav-entou in 1820 by the preparations of quinine and cinchonine. In 1833 quinine became partially known, being completely isolated as an active principle in 1852, quinine and cinchonine having been employed since 1820-21.

Until the researches of Marchiafava, Celli, Laveran, Golgi, and others had disclosed the true etiology of malaria, quinine was used empirically in malarial diseases, its precise action being unknown. Its efficacy is now ascertained to be due to its power of destroying the plasmodia of malaria. In addition to this action, which renders the drug of the greatest value in malarial diseases, quinine possesses many other important properties, which are here considered.

Antagonists and Incompatibles. - Agents promoting waste -such as the salts of mercury, iodine, copper, zinc, lead - are therapeutically antagonistic to cinchona. The cerebral effects of quinine are antagonized by morphine, while atropine opposes its action upon the nervous and circulatory systems, as well as its antipyretic powers.

The incompatibles are free tannic acid, alkalies and alkaline earths, and iodine. Fowler's solution is incompatible with infusion and decoction of cinchona.

Synergists. - All agents promoting constructive metamorphosis. The antipyretic action of quinine is enhanced by the antipyretics, many of the aromatics and antiseptics. Its antiperiodic action is aided by arsenic, phenol, creosote, and many of the aromatics.

Physiological Action. - Externally and Locally. - The drug is a mild germicide, preventing putrefaction and fermentation by its destructive influence upon fungi and infusoria, a solution of I: 250 being sufficient for this purpose, while 1: 500 is fatal to certain micro-organisms, and even so weak a solution as 1: 1000 suffices to destroy some infusoria.

Quinine is essentially a protoplasm-poison. It affects lower animals and plants, interferes, when present, with the normal processes of reproduction, affects the blood-cells, and, moreover, has a peculiar action in diminishing the activity of many of the unorganized ferments.

Upon the unbroken skin it has little effect, other than to produce occasionally a slight roughening of the surface. To raw surfaces, however, and to mucous membranes it is irritant.

Internally. - Digestive System. - Its action resembles that of vegetable bitters, augmenting the secretions from the salivary and gastro-intestinal glands, stimulating peristalsis, and increasing the blood-supply to the stomach. Under moderate doses, therefore, the appetite and digestion are improved. Large dosage disturbs digestion, occasioning nausea, with, possibly, vomiting and diarrhea. The acidity of the stomach is said to be increased by quinine sulphate.

Circulatory System. - Small doses increase the force and frequency of the heart's action, excessive doses slowing and weakening it, and, frequently in children, causing an intermittent pulse. Toxic doses paralyze the heart, arresting it in diastole. It is uncertain whether or not these effects are due to an exclusive action on the cardiac muscle. It is evident, though, that small doses elevate, and large doses depress, arterial tension.

Quinine in a remarkable manner affects the constituents of the blood. The ameboid movements of the white blood-corpuscles are arrested, preventing their migration through the capillary walls in inflammation, while their number is diminished by full doses of the drug both in health and in inflammatory conditions. The red corpuscles are relatively increased in number, at least in proportion to the white corpuscles, the size of the former being diminished in febrile conditions.