BENZYLIC ALDEHYDE. 317 



benzhydrolic ether (C 13 H n ) 2 0. But slightly soluble in 

 water, easily soluble in alcohol and ether. Oxidizing 

 substances reconvert it into benzophenone. 



Benzhydrol acetate, C 13 H n .O.C 2 H 3 0. Colorless 

 liquid, boiling at 301-302 ; does not congeal at 15. 



Tollylene alcohol, C 8 H 10 2 = C 6 IP j cip.OH. Is 

 obtained by heating tollylenebromide (p. 285) with 

 water at 170-180. Colorless needles. Fusing point, 

 112-113. Easily soluble in water. Diatomic alcohol. 

 Oxidizing substances convert it into terephtalic acid. 



Tollylene acetate, 9 6 H 4 (CH 2 .O.C 2 H 3 0) 2 . Hard, 



shiny laminae. Fusing point, 47. 



D. ALDEHYDES. 



1. Benzylic Aldehyde (Oil of Bitter Almonds). 

 C 7 H 6 = C 6 H 5 .CIIO. 



Formation and preparation. Together with hydro- 

 cyanic acid and sugar by the action of dilute acids or 

 emulsin (an albuminous substance contained in almonds) 

 on amygdalin (see Glucosides). By the distillation of a 

 mixture of calcium benzoate and formate. By the 

 oxidation of benzyl alcohol with nitric acid ; by heat- 

 ing benzal chloride (p. 275) with water at 130-140, 

 with alcoholic potassa or with mercury oxide ; by dis- 

 solving benzal chloride in concentrated sulphuric acid 

 at 50, and afterward adding water; by boiling benzyl 

 chloride with dilute nitric acid, or, better, with a dilute 

 solution of lead nitrate ; by conducting the vapor of 

 benzoic or phtalic acids over heated powdered zinc. 

 In order to prepare it, bitter almonds or other vegetable 

 substances, containing amygdalin, freed of fixed oil by 

 pressing, are stirred up with water, allowed to stand a 

 day, and the mass then distilled. The oil passes over 

 with the water, together with hydrocyanic acid, and 



27* 



