OXYBENZOIC ACIDS. 343 



2. Cuminic acid, C 6 II 4 j QQ QJJ 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. Acids, C 11 !! 14 ^. 



Homocuminic acid, C 6 H 4 j Qjp QQ QJJ Is pro- 



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

 by boiling it with alcoholic potassa. Small crystals, 

 fusing at 52. 



b. Monobasic, Diatomic Acids. 

 1. Oxybenzoic Acids. 



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 Spircea 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- 



