OXYNAPHTHOIC ACID. 403 



acid. Long, colorless needles ; fusing point, 182; 

 boils above 300 without undergoing decomposition. 

 But slightly soluble in boiling water, easily soluble in 

 alcohol and ether. Heated with barium hydroxide, it 

 is resolved like naphthoic acid into carbonic acid and 

 naphthalene. 



Barium isonaphthoate (C n H 7 2 ) 2 Ba + 4H 2 0, and 

 Calcium isonaphthoate (C^IFO^Ca + 3H 2 0, crys 

 tallize in needles and are insoluble in cold water (in 

 1400-1800 ^arts at 15). 



3. Oxynaphthoic Acid (Carbonaphtholic Acid). 



The sodium salt is produced by the simultaneous ac 

 tion of sodium and carbonic anhydride on a-naphthol. 

 Hydrochloric acid precipitates the acid from the solu 

 tion of this salt. Small, stellate, colorless needles ; 

 fusing point, 185-186; but slightly soluble in water 

 even at boiling temperature, easily soluble in alcohol 

 and ether. Its salts are, for the greater part, difficultly 

 soluble in water. These solutions are turned deep 

 blue by iron chloride. 



$-Naphthol (p. 399), when treated in the same way, 

 yields with difficulty an isomeric oxyacid of similar 

 properties. 



