Griffith's materia medica and pharmacy : for the use of medical and pharmaceutical students.

Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: Griffith's materia medica and pharmacy : for the use of medical and pharmaceutical students. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    431/480 (page 419)
    weiglit of chloroform = 119'5, multiplied by 2 = 239. There- fore, as 331 grains of chloral are equivalent to 239 grains of chloroform, 100 grains of chloral will equal 72*2 grains of chloroform—331 : 100 :: 239 : 72-2. Chloral hydrate occurs in colourless crystals, which do not deliquesce on exposure to air. It has a pungent but not an acrid odour, and a pungent and rather bitter taste. On the application of a gentle heat it fuses to a colourless transparent liquid, which, as it cools, begins to solidify at a temperature of about 120°. It boils in a test-tube, with pieces of broken glass immersed in it, at about 205°, and at a slightly higher temperature it volatilises on platinum foil without residue. Soluble in less than its own weight of distilled water, rectified spirit, or ether, and in four times its weight of chloroform. The aqueous solution is neutral or but slightly acid to test- paper. A solution in chloroform, when mixed by agitation with sulphuric acid, does not impart colour to the acid, show- ing freedom from chlorinated organic impurities (alcoholate of chloral). It is decomposed by alkalies into chloroform and an alkaline formate :— C2HC]30,H20 + KHO = KCHO^ + H^O-i-CHas. 100 grains of hydrate of chloral dissolved in 1 oz. of dis- tilled water, and mixed with 30 grains of slaked lime, sub- mitted to careful distillation with a suitable apparatus, should yield not less than 70 grains of chloroform. It enters into the preparation of the Syruims Chloral (p. 386). Chloroformum. Terchloride of Formyl, or Trichloromethane (CHCI3). The following is an abstract of the Pharmacopcx3ial method of preparing chloroform :—3 gallons of water and 30 oz. of rectified spirit are distilled with a mixture of 10 lb. of chlo- rinated lime and 5 lb. of slaked time; the first 50 oz. of the distillate is well washed with water, and after the mixture 27—2 •