OXYBENZOIC ACIDS. 343 



2. Cuminic acid, C 6 II 4 | nornr Is produced from 



cuminol (p. 325) by boiling with alcoholic potassa or 

 by adding to fusing caustic potassa ; probably also by 

 boiling cuminol with dilute nitric acid. Colorless, 

 tabular or prismatic crystals. Almost insoluble in cold 

 water, very difficultly in hot water, easily soluble in 

 alcohol. Fuses at 113, and sublimes without decom 

 position in long needles. Is converted into terephtalic 

 acid when oxidized with nitric or chromic acids ; and 

 yields cumene when heated with lime. 



5. Adds, C 11 !! 1 ^ 2 . 



Homocuminic acid, C 6 II 4 j ^p QQ Q H Is pro 

 duced from cumyl cyanide (from cumine alcohol, p. 316) 

 by boiling it with alcoholic potassa. Small crystals, 

 fusing at c 52. 



b. Monobasic, Diatomic Acids. 



1. Oxybenzoic Adds. 

 , OTF03 = C H&amp;lt;{gJ on 



The three isomeric oxyacids corresponding to the 

 other substitution-products of benzoic acid are well 

 known. 



1. Salicylic acid (Ortho-oxybenzoic acid). Is con 

 tained in the blossoms of Spiraea ulmaria ; and in the 

 form of the methyl ether in wintergreen oil (the vola 

 tile oil of Gaultheria procumbens). The sodium salt is 

 produced by the direct combination of phenol and 

 carbonic anhydride in the presence of sodium ; the 

 ethyl ether, by bringing a mixture of equal parts by 

 weight of phenol and chlorcarbonic ether (p. 222) to 

 gether with sodium. It is produced further by treat 

 ing saligenin and salicylous acid (p. 322) with oxi 

 dizing agents; by melting ortho-cresol (p. 298) and 

 salicin (see Glucosides) with caustic potassa ; by con- 



