CHLORAL HYDRATE, CO.:CHO -1 II:0, a crystalline solid composed of trichloral aldehyde with one molecule of water. The crystals are single, colorless. and transparent rhomboids melting. at F., rand with an aromatic penetrating and smarting taste and slightly acrid odor. They are freely soluble in alcohol, turpentine, c.hloroforni and ether. Chloral hydrate is a•powerful germicide but is rarely used as such save to preserve mia tornical preparations. It is a vesicant and a local analgesic. In small doses' it causes burn ing sensations of the stomach, but little general action. Full medicinal doses, 5 to 15 grains, cause a slowing of the pulse, dilatation Of the arterioles, lowering of blood pressure and slow ing of the respiration. On the nervous system it acts as a depressant, causing sleep by direct action on Ole brain cells. Large doses cause poisoning with symptoms of collapse, coma with a feeble, thready pulse, lowering of temperature, cyanosis or lividity, cold perspiration, dilated pupils, and loss of reflexes. Death results from respiratory and cardiac paralysis. Treatment of
poisoning is by rousing patient to maintain res iiratory centre, artificial heat, artificial respira tion, hot coffee by mouth or rectum and cardiac stimulants. Chloral is particularly valuable in overwork and in many of the cdnvulsive disorders, tetany, myticlonus, status epilepticus and delirium tremens.Its action is possibly due to the formation of chloroform in the general circulation, by .the action of the alkalis contained in the blood, in accordance with the equation CCILCH (OH), -17 KOH CFICls +ILO CHO.OK, the last formula in equation being' that of potassium formate. It is alsp .useful' in states associated with high arterial tension, ff the heart is not weakened. Within recent years a large number of allied drugi have been introduced. They have similar actions' but are more palatable -or are thhught to••cause less heart depression.. Among 'these may be mentioned chtoralamide,. chloretotie, chloralose. and urethane.