346 OXYBENZOIC ACID. 



slightly soluble in water, more readily in alcohol. 

 When distilled (best when previously mixed with sand 

 and baryta), they are decomposed like salicylic acid, 

 yielding carbonic anhydride and substitution-products 

 of phenols. By the action of vapors of sulphuric 

 anhydride and subsequent treatment with water, it is 



converted into sulphosalicylic add, C 6 H 3 (OH) j QQ OH 



Nitrosalicylic acid (Anilic acid), C 7 H 5 (N0 2 )0 3 , is 

 formed by treating salicylic acid, indigo, or salicin with 

 nitric acid. ISTeedly crystals, very difficultly soluble in 

 cold water, more easily in hot water and in alcohol. 

 "When boiled with nitric acid it is converted into picric 

 acid. 



Amidosalicylic acid, C 7 H 5 (NH) 2 3 = 

 C 6 H 3 (NH 2 ) | QQ OH Is obtained by the reduction of 



nitrosalicylic acid with tin and hydrochloric acid. 

 Needles of the lustre of satin. Insoluble in cold water 

 and alcohol, difficultly soluble in hot water. Combines 

 with bases and acids. Easily decomposable. At a high 

 temperature it is resolved into carbonic anhydride and 

 isoamidophenol (p. 294). 



2. Oxybenzoic acid (Meta-oxybenzoic acid), 



{O TT 

 CO OH ^ s P r d uce d by conducting nitrous 



acid into a dilute aqueous solution of amidobenzoic 

 acid ; by boiling nitric-diazobenzoic acid (p. 332) with 

 water ; and by melting metachlor-, metaiodo-, metasul- 

 phobenzoic acids, and meta-cresol with caustic potassa. 

 Crystalline powder, consisting of small quadratic 

 plates, or large verrucose crystals, without water of 

 crystallization. But slightly soluble in cold water, 

 more readily in hot water. Fuses at 200, and is de- 

 composed only at a very high temperature. 



