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To Purify Hydrate of Chloral

for 5 minutes with an equal volume of sulchloral hydrate is insoluble at ordinary temphuric acid; when settled, transfer the upper perature; four parts of it dissolve gradually stratum to a flask containing 2 ounces chloride in one part of water, the solution crystallizes of calcium in small pieces, and ounce perat 32° Fahr., but not in well-formed crystals. fectly dry slacked lime. Agitate thoroughly, Alcohol and ether dissolve it to such an exand, after an hour, distill the pure chloroform tent that it likewise does not crystallize well over a water-bath. Keep in a well-stoppered on evaporating these solvents; absolute albottle, in a cool place. The U. S. Dispensato-cohol must be excluded, because it combines ry has transferred this from the British Phar- with chloral. Chloroform and benzole are macopœia, consequently avoirdupois weight well adapted for recrystallization, but the and Imperial measure are adopted. 4274. To Purify Commercial Chloro-ly removed from the crystals. The same first is too dear, and the last cannot be entireform. To 102 troy ounces commercial holds good for most other liquid solvents, but chloroform add 17 troy ounces sulphuric acid, uniformly satisfactory results are obtained occasionally shaking during 24 hours. Sepa- with bisulphide of carbon; 45 parts of it disrate the lighter liquid and mix it with 6 fluid solve at 60° to 65° Fahr., but 1 part chloral drachms stronger alcohol. Then add 2 troy hydrate; it precipitates ethereal and alcoholic ounces carbonate of potassa, previously heatsolutions of the latter. But at temperatures ed to redness, and rubbed into powder while below the boiling of bisulphide of carbon, 4 warm. Agitate thoroughly and distill to dry- to 5 parts of it are sufficient for dissolving 1 ness. Keep the distilled liquid in well-stoppart chloral hydrate. If allowed to cool ped bottles. (U. S. Ph.) 4275. Tests for the Purity of Chloro- length, are obtained, easily collected, and slowly, beautiful crystals, often an inch in form. Its specific gravity should not be readily freed from the last traces of the solless than 1.490, nor more than 1.494; and vent by exposing them in thin layers to the should boil at 140° Fahr. When dropped air. (Flückiger.) very limpid fluid, having a penetrating and agreeable smell and a burning taste. into water, it sinks in transparent globules without milkiness. When mixed in a bottle oxide of ethyl-is a colorless, transparent, 4279. Sulphuric Ether-also called with an equal bulk of sulphuric acid, it should produce no warmth; and after standing for 24 hours, neither liquid should be discolored, or, at most, a faint yellow tinge imparted to the lower or acid stratum; more discoloration than this would denote the presence of empyreumatic oily matter. When evaporated on a porcelain plate, it leaves behind a slightly aromatic odor, but free from pungency. by ice or water; continue to distill until a Put 2 pounds rectified spirit into a glass re- 4280. Το Obtain Sulphuric Ether . tort, and add 2 pounds sulphuric acid; place the retort on a sand-bath, and apply heat so that the liquor may boil as quickly as possible, and the ether pass into a receiver cooled