BENZYLIC ALDEHYDE. 321 



and chlorbenzil. Thin laminae. Slightly soluble in 

 water, easily in alcohol and ether. Fuses at about 

 55. Distils without decomposition. "With phosphorus 

 chloride it yields monochlor stilbene, C 14 H H C1; heated 

 with hydriodic acid, dibenzyl (p. 282). 



Toluylenhydrate, C 14 H 14 0. Is produced by the 

 action of sodium-amalgam on desoxy benzoin ; and by 

 heating desoxybenzoin or hydrobenzoin with alcoholic 

 potassa. Long, fine, brittle needles, of a vitreous 

 lustre. Fusing point, 62. Insoluble in water, easily 

 soluble in alcohol and ether. Nitric acid oxidizes it 

 readily, forming desoxybenzoin. "When boiled with 

 dilute sulphuric acid it is resolved into stilbene and 

 water. With acetyl chloride it yields a thick liquid 

 ether, C 14 H 13 .O.C 2 H 3 0. 



Benzil, C 14 H 10 2 . Is produced by the oxidation of 

 benzoin with nitric acid or chlorine; and, together with 

 stilbene, by heating stilbene bromide with water, alco- 

 hol, or silver oxide. Large, six-sided columns, taste- 

 less and inodorous, insoluble in water, soluble in alco- 

 hol and ether; fusible at 90. Hydrogen (iron filings 

 and acetic acid, or zinc and hydrochloric acid) recon- 

 verts it into benzoin. 



Chlorbenzil, C 14 H 10 C1 2 0. Is produced by gently 

 heating benzil with phosphorus chloride. Rhombic 

 prisms or plates. Fusing point, 71. Insoluble in 

 water, difficultly soluble in alcohol. When heated 

 with concentrated nitric acid, or with water or alco- 

 hol to 180, it yields benzil ; when heated with phos- 

 phorus chloride to 200, tolan tetrachloride ; with zinc 

 and hydrochloric acid, desoxybenzoin. 



Benzilic acid, C 14 H 12 3 , is produced from benzil, 

 when this is heated to boiling with a concentrated 

 alcoholic solution of potassa. After saturating the 

 solution with hydrochloric acid, benzilic acid separates 

 from the hot filtered solution in long, lustrous needles, 

 which fuse at 150. But slightly soluble in water, 



