071 the Ammonia-cohalt Bases. 89 



i 



smaller quantity of anotlier salt, wliicli appears to be tlie clilorid 

 of a distinct base, but which is not yet fully studied.* 



The equation wbich represents the formation of the clilorid of 

 Xanthocobalt by double decomposition^ is simply 



XO2 . 5NII3 . C02O3, 2SO3 + 2BaCl=2BaO, SO3 + If O2 . 5NH3 . C02O, CI2 



The chlorid of Xanthocobalt crystallizes in brown-yellow crys- 

 tals, which when large, have a faint reddish tinge. They are 

 usually very well definedj and exhibit a beautiful iridescence 

 upon their surfaces, but we cannot at present describe their form. 

 The salt is quite soluble in hot water, but the solution is easily, 

 though only partially, decomposed at a boiling heat, and even, 

 Avhen quite neutral, at a lower temperature. On boiling, ammo- 

 nia is evolved in abundance, while a heavy black precipitate is 

 thrown down ; it requires very long boiling to produce a com- 

 plete decomposition. The salt is rather insoluble in cold water; 

 chlorhydric acid precipitates it unchanged in the cold, and the 

 same effect is produced by the solutions of the alkaline chlorids. 

 Acids, even when dilute, easily and completely decompose the 

 chlorid of Xanthocobalt by boiling. Chlorhydric acid in large 

 excess, by long boiling, converts the salt completely into chlorid 

 of Purpureocobalt, deiitoxyd of nitrogen, and occasionally chlo- 

 rine, being given off. Sulphuric and nitric acid also decompose 

 the chlorid, but with these acids the decomposition generally 

 goes so far as to produce salts of cobalt, or double salts of cobalt 

 and ammonia. Oxalic acid also produces complete decomposi- 

 tion by long boiling, oxalate of cobalt and oxalate of ammonia 

 being formed. Even strong acetic acid produces, on boiling 

 with the salt, a partial decomposition. Alkalies readily decom- 

 pose a solution of the chlorid when heated, ammonia being 

 evolved, while a black powder is thrown down. The dry chlo- 

 rid is easily decomposed below a red heat. An abundance of 

 red vapors is at first given off, afterward ammonia is evolved, 

 1^ and finally a black superoxyd of cobalt remains, 



Eeducing agents, in certain cases, completely decompose the 

 solution of the chlorid of Xanthocobalt, giving salts of cobalt 

 and ammonium. Thus a current of sulphydric acid gas passed 

 for some time through the solution gives a precipitate of sulphur 

 and sulphid of cobalt, while nitrogen ga^ escapes, and chlorid 

 and sulphid of ammonium remain in solution. The decomposi- 

 tion is similar in an acid solution, but of course no sulphid of 

 cobalt is precipitated. 



We made this experiment in the hope of decomposing the 

 NO 2 in the chlorid in a manner similar to the w^ell known reac- 



F 



It IS this chlorid in an Impure state to "which, in my Report on the Recent Pro- 

 gress of Organic Chemistry, the formuk 2NOii,5NH3 .CoaOaCl, is attributed, and 

 "which is there called Dixanthocobalt. — "W. o. 



SECOND SERIES, VOL. XXIV, KO. 70. — JULY, 1^7. 



12 



J 

 J 



j^ 



i 



