CHLORAL : ITS DERIVATIVES AND COMPOUNDS.—Chloral, or anhydrous chloral, is by no means chloral-hydrate, as is generally imagined and so very erroneously taught. Chloral, per se, is a trichloracetic aldehyde, and can be obtained only in the form of a color less liquid, which, when shaken with water, absorbs one molecule of the latter and forms a solid, constituting chloral hydrate. It also possesses an aldehyde odor; it boils at 201.2° F., while chloral hydrate only boils at 207° F. By ox idation it forms trichloracetic acid, and the action of nascent hydrogen reduces it to aldehyde; by the alkalies it is at once decomposed into chloroform and a formate of the alkali employed. True chloral is difficult to keep, and always requires to be tightly' corked in a dark hued container and carefully set away in a dark, cool place. It possesses little interest for the physician, except as be ing a source of chloral-hydrate, and the fact that sulphuric acid added to the latter causes it to decompose into meta chloral and chloral.
Preparations and Doses.—Chloralamid (chloralamide; chloral-formamide), 10 to 45 grains.
Chloral-ammonium, 15 to 30 grains. Chloral-antipyrine (hypnal), 15 to 30 oTains.
Chloral-caffeine, 3 to 10 grains. Chloral-camphor (camphorated chlo ral), topical chiefly; internally, 10 to 20 Chloral, croton- (see BUTYL-CHLORAL). Chloral-formamide (see CHLORAL AmiD).
Chloral-hydrate, 10 to 50 grains. Chloral-imide (chloralamid; trichlo rethylidenimide), 10 to 30 grains. Chloral-menthol (menthol-chloral; mentholated chloral), for topical use. Chloral-ose, or chloralose, 1 to 3 grains.
Chloral-quinine, 3 to 10 minims. Chloral-thymol, topical application only.
Chloral-urethane (ural; uraline; lium; urethane-chloral), 10 to 45 grains. Chloral suppository, 15 grains of mixt Luz.
Chloral syrup, 30 to 120 minims.
Chlorobrom, or chloro-brom: a mixt ure of potassium bromide and chloral amid.
Bromoehloral, compound liquid of, 30 to 120 minims.
13utyl-chloral-hydrate, 15 to 30 grains. Butyl-chloral mixture, 4 to S drachms. Butyl-chloral pills, 1 every one or two hours.
Butyl-chloral pills with gelseinium, 1 every one or two hours.
Chloral-antmonimn, is a white, crys talline powder with a chloral odor and taste, soluble in alcohol and ether, in soluble in cold and decomposed by hot water, melting at about 147° F. It is employed as an hypnotic and analgesic, is claimed never to disturb the stomach, and to be devoid of all the unpleasant factors peculiar to chloral-hydrate: claims by no means substantiated. It is
employed chiefly in nervous insomnia of all kinds and also in mental troubles.
Chloral-anti pyrine is, perhaps, better known by its trade name: "hypnal." It is scarcely so much a chemical as a mechanical compound, and is had in colorless crystals that are soluble in six parts of water. It is hypnotic, analgesic, antipyretic, and antiseptic, and chiefly employed in insomnia, headache, spasm, cough, etc.
Chloral-hydrate is the drug in most frequent use, and, as already remarked, is obtained by the addition of one mole cule of water to anhydrous chloral, whereby are formed crystals (monoclinic prisms) melting at 135° F., and at 207.5° separating into chloral and water; the vapor is not combustible. It has a some what pleasant, penetrating; pungent, aromatic odor, in which, also, is speedily recoo-nized more than a mere suffcrestion of acridity. Bitter to taste, it is also, ILI (JIlle uegiee. eaut,Lic; mure leJS volatile according to the atmospheric conditions to which it is exposed; solu ble in almost anything and everything, including fixed and volatile oils; and, when triturated with equal proportions of stereopteus or camphoraceous bodies, combines to produce a liquid. A great deal of the chloral-hydrate marketed is of impure quality, being in combination with chloral-alcoholate (to the presence of which untoward accidents are fre quently laid), hydrochloric acid, chlo rides, etc. The test authorized by the British Pharmacopoeia is that of sul phuric acid acting on a strong solution of the drug in chloroform, whereby, if absolutely pure, no brown color is devel oped; the U. S. P. directs the acid to be employed without chloroform and the mixture also to be warmed, and re quires it shall not blacken. Manifestly the last test is not as reliable or delicate as that of the B. P. A fair idea of purity can be had, however, by pressing be tween two leaves of blotting-paper, when, if impure, oily spots will be formed. It should make a neutral solution with water without forming oily drops; should not be decomposed readily by the action of the atmosphere; the aqueous solution acidulated with nitric acid affords no evidence of chlorine when treated with silver nitrate.