are slowly added through the condenser, and after each addition the flask is well shaken. A gentle reaction sets in and the temperature rises. At the same time the surface of the brownish yellow solution takes a violet red tint, which rapidly fades, the liquid finally assuming a deep red colour. When the whole of the chloroform has been added the contents of the flask are boiled for hour without removing the condenser, and a yellow semi-solid mass separates out of the solution. The unattacked chloroform is now distilled off on the water-bath, the liquid diluted with water and strongly acidified with dilute hydrochloric or sulphuric acid. A thick dark red oil separates out on the surface, which is subjected to distillation in steam. An oil having a faintly yellow colour distils over with the water and settles to the bottom of the receiver. When drops of oil cease to condense, the distillation is stopped. The distillate, which contains salicylaldehyde and phenol, is extracted with ether and the ethereal solution well shaken with a saturated solution of sodium bisulphite. The bisulphite compound of salicylaldehyde separates out in colourless needles, which are filtered, washed free from traces of phenol with alcohol and then decomposed by heating with dilute sulphuric acid. The aldehyde which separates out is taken up with ether and the ether driven off. It is dehydrated over calcium chloride and finally distilled. In the distilling flask from which the salicyl aldehyde has in the first instance been removed with steam, there remains a brownish liquid and a dark red substance, which sinks to the bottom of the vessel and forms a brittle resin on cooling. The aqueous portion is filtered hot through a moistened filter, which retains the resin, and the filtrate containing p-oxybenzaldehyde formed simultaneously in the above reaction is extracted when cold with ether. On distilling off the solvent, p-oxybenzaldehyde remains in the form of a yellow mass of stellar-shaped needles, which may be purified by recrystallisation from small quantities of hot water. ONa C&H2ONa+3NaOH+CHCl3=CHACHO+3NaCl + 2H2O Sodium Phenate Chloroform Sodium Salicylaldehyde Properties-Salicylaldehyde. Colourless pleasant smelling oil, b. p. 196'5°; sp. gr. 11731 at 13'5°; solidifies at -20° in large crystals. Volatile in steam; soluble in water; miscible in all proportions with alcohol and ether. The aqueous solution is coloured deep violet with ferric chloride. Paraoxybenzaldehyde. Colourless needles; m. p. 115-116°; with difficulty soluble in cold water, more readily soluble in hot water, alcohol, and ether. Not volatile in steam. The bisulphite of sodium compound is easily soluble in water. Ferric chloride colours the aqueous solution violet, PREPARATION XXV. ACETOPHENONE, C,H,O=C,H,.CO.CH3. (Phenylmethylketone.) 5 LITERATURE.-Friedel (1858), Compt. rend. 47, 552. One hundred grms. finely powdered and anhydrous calcium benzoate are thoroughly mixed with 50 grms. dry powdered calcium acetate. An iron tube is half filled with the mixture. The tube is placed in a furnace, connected with condensing tube and receiver (Fig. 17), and rapidly heated from the open end towards the closed end until no more liquid condenses. A brown oil distils over. The distillate, which contains a little water, is dehydrated over calcium chloride and fractionated. A small quantity of a colourless low-boiling liquid containing benzene first distils, the temperature then rises quickly to 1 Preparation of Calcium Benzoate and Acetate.-A hot solution of 100 grms. benzoic acid in about 1 litre water is made alkaline with milk of lime, filtered from excess of lime and concentrated. The hydrated lime salt crystallises on cooling in long needles, which are separated from mother-liquor, dried at 100°, finely powdered, and then freed from water by heating the salt on a flat iron tray with constant stirring until moisture ceases to condense on the cold surface of a watch-glass held above the substance. Calcium acetate is prepared similarly. 195°, and the product boiling at 195-205° and possessing a faint yellow colour is separately collected. This portion is fractionated between 198° and 202° and is nearly pure acetophenone. It crystallises on cooling to o°. (C6H5COO),Ca + (CH,COO),Ca Calcium Benzoate Calcium Acetate 2C6H5COCH ̧ + 2CaCO3 Acetophenone. Properties.-Colourless tabular crystals; b. p. 202°; Literature. —Liebig, Wöhler (1832), Ann. Ch. Pharm. 3, 276; Zinin (1840), Ann. Ch. Pharm. 34, 186; Zincke (1879), Ann. Ch. Pharm. 198, 151. Fifty grms. benzaldehyde are added to a solution of 5 grms. commercial potassium cyanide in 200 grms. alcohol 50 per cent., and the mixture is heated on the |