CREN′IC ACID. A brown substance discovered by Berzelius in certain mineral waters. It is a modification of HUMUS, and is produced by the decay of vegetable matter.
CRESYLIC ACID. C7H8O. Syn. Cresol, Kresylic acid, Kresol. One of the homologues of carbolic acid, found in coal tar. Cresylic, like carbolic acid, is a useful disinfectant.
CRIB-BITING.—The use of deal or any unseasoned wood for the manger may induce this habit in horses. To remedy it the stable fittings should be of iron. As the habit very frequently arises from acidity of stomach in horses, the administration of chalk or other antacids has been recommended.
CRICK′ETS. These insects may be destroyed by putting Scotch snuff into their holes, or by placing some pieces of beetle wafers for them to eat.
CRINUM ASIATICUM. (Ind. Ph.) Habitat. Low humid localities in Bengal, the Concans, and other parts of India; also cultivated in gardens; Ceylon, the Moluccas, and Cochin China.—Officinal part. The fresh root (Crini Radix); bulbous, with a terminal stoloniferous fusiform portion issuing from the crown of the bulb; emits an unpleasant narcotic odour; readily dried in a stove, and reducible to powder after desiccation.—Properties. Emetic; in small doses nauseant and diaphoretic.—Therapeutic uses. Analogous to those of squill.
Juice of Crinum (Succus Crini; Infusum Crini, Beng. Ph.). Take of the fresh root of crinum, 1⁄2 an ounce; cold water, 2 ounces. Bruise the root in a stone mortar, gradually adding the water. Strain, with pressure, through calico.—Dose. From 2 to 4 fluid drachms, every twenty minutes, until the desired effect is produced.
Syrup of Crinum (Syrupus Crini). Take of the fresh root of crinum, sliced, 8 ounces; boiling water, 1 pint; refined sugar, 1 pound. Macerate the root in the water for two hours, bruise in a mortar, press through calico, add the sugar, and dissolve with the aid of gentle heat.—Dose. About 2 fluid drachms, repeated as required. Used as a nauseant and emetic for children.
CROTON CHLORAL. Syn. Butyl chloral. A colourless oleaginous liquid, having an odour somewhat like that of ordinary chloral; insoluble in water. Croton chloral may be prepared by the process of Krämer and Pinner, who were the first to obtain it. A current of chlorine gas is passed into aldehyd during twenty-four hours. At the commencement of the operation the action is very energetic; so much so that it is necessary to surround the vessel containing the aldehyd with a refrigerating mixture, and it is only towards the end that the temperature is raised to 100° C. Large quantities of hydrochloric acid are generated during all the time the chlorine is acting on the aldehyd. The resulting product is submitted to fractional distillation, and the liquid passing over between 163° and 165° C. is croton chloral. Croton chloral is the hydride of trichlorcrotonyl (C4H2Cl3OH), or the aldehyd of crotonic acid (C4H5OOH) in the radical of which three atoms of hydrogen have been replaced by three atoms of chlorine. Like ordinary chloral, croton chloral combines with water to form a crystallised hydrate which is the substance used in medicine. Croton chloral hydrate occurs in white nacreous spangles. It is very slightly soluble in cold water, more so in warm, and extremely soluble in alcohol. A convenient solvent for it is glycerin, in which it dissolves much more easily than in water. The dose of the hydrate as a hypnotic is from 8 to 15 grains, for neuralgia 5 grains are given three times a day. Dr Liebreich, who first introduced croton chloral to the notice of the medical profession, says he has failed to discover that it exercises any hurtful effects on the stomach and other organs. On the contrary, Dr Worms asserts that he finds it not so generally tolerated as ordinary chloral, and Gay affirms that it is more uncertain in its narcotic effects.
CRO′TON OIL. Syn. Oleum croto′nis (B. P.), O. tiglii (Ph. L. & D.), L. The “oil expressed from the seeds of Croton tiglium” or purging croton. This oil is a drastic purgative, and a powerful local irritant and rubefacient. Rubbed on the skin, it produces a pustular eruption, and frequently purges. In this way (diluted with thrice its weight of olive oil) it is occasionally used as a counter-irritant.—Dose (as a purge), 1 to 2 drops; in obstinate constipation, lead colic, &c.
The residuum from which the oil has been expressed is sometimes used in veterinary practice under the name of croton cake, or croton farina; but as the amount of oil it contains varies greatly, it is irregular and uncertain in its effects.