Syrup of chloral is obtained by dis solving SO grains of chloral-hydrate in 90 minims of water, and then adding simple syrup enough to make 1 ounce.
Butyl-chloral-hydrate—or croton-chlo ral-hydrate as it is sometimes, but wrong fully, termed—appears in pearly-white crystalline scales possessed of a pungent odor resembling that of chloral-hydrate, and an acrid nauseous taste; it is solu ble, 1 to 43, in cold water, freely solu ble in rectified spirit, and 4 to 1 of glyc erin. It is available in the same way as chloral-hydrate, and is claimed to be more efficacious as an analgesic, espe cially in neuralgias.
Butyl-chloral-antipyrine or butyl-hyp nal, appears as colorless, transparent needles of butyl-chloral odor and bitter taste, which are soluble in alcohol, ether, chloroform, benzin, and (1 to 30) water. Perchloride of iron gives a red solution; alkalies decompose into antipyrine, alka line formate, and propyl-chloroform. Its properties resemble those of hypnal. Butyl-chloral mixture, which is a very useful anodyne, is made by dissolving 4 grains of butyl-chloral in 15 minims of frlycerin and water to make 1 ounce.
Butyl-chloral pills are made of a strength of 3 grains each of the drug added to sufficient glycerin of traga canth or mucilage of gum arabic to make a mass; when the same are desired with gelsemium, hydrochlorate of gelse mine, in the proportions of of a grain, is added to each pill.
Butyl-claoral syrup is merely 16 grains of the drug dissolved in 1 ounce of hot syrup.
Glycerite of chloral is merely 1 part of chloral-hydrate in 4 parts of glycerin, and is employed chiefly as a solvent for certain alkaloids.
Glycerole of camphor and chloral, which is a very effective anodyne em brocation, is made as follows:— I; Camphor, powdered. 75 grains. Chloral-hydrate, GO grains. Glycerin, 4 drachms.
Alcohol, 3 drachms.
Juniper-oil, 30 minims.
Mix in a glass container and expose to gentle heat (not over 104° F.) until solution is effected. Let cool, bottle, and keep well stoppered.
Carmine-chloral—which is so useful to microscopists as a stain, and invaluable in examining pollen nuclei—is made as follows: Carmine, 2; absolute alcohol, 20; hydrochloric acid, 2 parts; heated on a water-bath for thirty minutes; then, adding 25 parts of chloral-hydrate, cool and filter.
Hypodermic Use.—Chloral-hydrate has been administered hypodermically, but is generally to be condemned on account of its caustic action, the necessity of multiplying punctures, and of employing very dilute solutions. Vulpian declares that it tends to induce hrematuria, though not to the same degree as when employed by intravenous injection. Croton-chloral is a trifle more suitable from a remedial stand-point, but not from a physical one; it is also highly irritant. Leoni recommends the follow ing solution, 16 minims of which con tain 3/4 grain of the drug: Croton chloral, 16 grains; warm glycerin and eherry-laurel water, of each, equal parts ttp to 352 minims.
Physiological Action.—Externally ap plied, all chloral preparations are more or less irritant, but likewise antiseptic and sometimes analgesic.
Internally they are generally sedative to the nervous system, and secondarily to the heart: a feeling of lassitude, of irresistible drowsiness, or even sleep may be produced (though sometimes preceded by a stage of excitement, particularly in alcoholics), slowing of pulse and respira tion. and pupillary contraction. Sensi: bility and reflex excitability are not dis turbed by ordinary medicinal doses, but disappear when large amounts of the drug are exhibited. Tbere is also lower ing of temperature. Probably brain anmmia is induced, whereby sleep fol lows, the act being more nearly normal, physiologically, than that produced by any other drug, there being no malaise on awakening.
Liebreich, who first introduced chloral, believed that it exerted its effect through the circulation by liberating therein free chloroform and formic acid; but this seems improbable, because the alkali of the blood is too feeble to effect the trans formation, and its albmnin is considered antagonistic to such a process. _Again, no smell of chloroform can be observed in the breath, and no ansthetic effect is produced on the sleeper by moderate doses. Farquharson ("Therap. and Mat. Med.," '89).