344 SALICYLIC ACID. 



ducting nitrous acid into a dilute aqueous solution of 

 anthranilic acid (p. 330) ; in small quantity, by the ac 

 tion of fusing caustic potassa on phenol. Is prepared 

 most advantageously by warming gaultheria-oil with 

 potassa-ley, by which means it is converted into methyl 

 alcohol and potassium salicylate. From the solution 

 of this salt, the acid is precipitated by means of hydro 

 chloric acid ; and by recrystallization from hot water 

 it is purified. 



Colorless, inodorous prisms, difficultly soluble in cold 

 water ; fusing point, 155-156. Sublimable, when 

 carefully heated ; heated rapidly either alone or with 

 water, it is resolved at 220-230 into carbonic anhy 

 dride and phenol ; heated with hydriodic acid to 140- 

 150, the same decomposition takes place. Treated 

 with chromic acid it .undergoes rapid and complete 

 combustion, yielding carbonic anhydride and water. 

 Its solution turns deep violet when treated with iron 

 chloride. 



It conducts itself towards bases as a monobasic acid. 

 Under certain circumstances however the second hy 

 drogen-atom can be replaced by metals. The salts, 

 which are formed in this way, however, can, only with 

 difficulty, be prepared in pure condition, and are decom 

 posed even by carbonic acid. 



Methyl salicylate, C 6 H 4 j cao.CIP. B ^ distil ~ 

 ling Gaultheriaprocumbensvriihw&teT. Colorless oil of 

 a pleasant odor ; specific gravity, 1.197 ; boiling point, 

 224. But slightly soluble in water, easily soluble in 

 alcohol. Combines with bases in the cold, forming in- 

 stable salts, which are decomposed by heat. 



Ethyl salicylate, C 6 H 4 j QQ o ^jp is formed by 



distilling salicylic acid with alcohol and sulphuric 

 acid. Colorless oil, boiling at 221. 



Methylsalicylic acid, C 6 II 4 j C Q Q H By heating 

 2 parts of gaultheria-oil with 1 part of potassium hy- 



