Mons. R. Piria on the Combinations of Salicyle. 215 



acid closely resembles the benzoic ; it is scarcely soluble in 

 cold water, readily soluble in hot water, as well as in alcohol 

 and aether. By heat it sublimes with great facility. Mixed 

 with alkaline carbonates, salicic acid decomposes them, dri- 

 ving oflp carbonic acid, and forming a series of salts. Digested 

 with sulphuric acid, the new acid undergoes no obvious 

 change until the mixture is heated, and then the whole turns 

 black. Nitric acid does not affect salicic acid in the cold ; on 

 applying heat, however, violent and tumultuous action ensues, 

 dense red fumes are evolved, and a yellow solution is obtained; 

 this, by repose, deposits minute yellow bitter crystals, which 

 appear to be identical with the nitro-salicide obtained by the 

 action of nitric acid on hydruret of salicyle. 



Salicic acid contains an atom of combined water, which it 

 loses when it combines with bases; hence the crystallized 

 acid is a salicate of water, or (14 C, 5 H, 5 O, -{- HO). 

 Submitted to ultimate analysis, this consists of 



Carbon .... 



Atoms. 

 .. 14. = 



84 



Theory. 

 61-32 



Exp. 

 61-10 



Hydrogen . 

 Oxygen .... 



.. 6 

 .. 6 



6 



48 



4.-29 

 34-39 



4-41 

 34-43 



Theory. 



Exp. 



34.-70 



34-91 



2-02 



2-09 



16-22 



16-43 



47-06 



46-57 



Atomic weight... 138 100 100 



Salicate of silver was prepared by precipitating a solution of 

 salicate of ammonia by nitrate of silver ; this salt is a white 

 insoluble powder, and consists of 

 Atoms. 



Carbon 14 = 84 



Hydrogen ... 5 5 



Oxygen 5 40 



Oxyd of silver 1 116 



Atomic weight... 245 100 100 



Chloride of Salicyle. 

 This compound may be obtained by a process precisely 

 similar to that used for the preparation of the chloride of 

 benzoyl, by transmitting a current of dry chlorine gas through 

 pure hydruret of salicyle ; much heat is evolved, the chlorine 

 unites with the hydrogen of the hydruret to form hydro- 

 chloric acid, which is copiously given off in a gaseous state, 

 whilst the salicyle itself unites with more chlorine to form the 

 chloride. A nearly solid crystalline mass is obtained, which 

 should be purified by solution in alcohol and subsequent 

 crystallization. The chloride of salicyle thus obtained is in- 

 soluble in water and acids ; but in aether, alcohol, and alkaline 



