on the Ammonia' cobalt Bases. 97 



I 



0*614:5 gr;?. gare 187*45 c. c. nitrogen at 6°-5 C, and 769'""»'5 (at 7° C), (h 



35771771-0) = 174-55 c. c at 0^ and 760^^"^ = 35-73 per cent. 



06024 grs. gave 283-SO c. c. of nitrogen at 5*^ C, and 759'""'-9 (at 6° C), (h 



3Ymm 0) = 169-20 c. c, at O'' and 760™"* — 35-27 per cent. 



0-5912 grs. gave 18466 c. c. nitrogen at 11°'5 C, and 761'"^0 (at 12"=* C), (h 



32'«'»-5) = 1671 3 c. c. at 0° and 760""» = 35-50 per cent 



Hence we 



m 



have 



Eqs. 



2 



16 



8 



16 



Calculated. 



590 18-73 



160 5 08 



112-0 3555 



128 40-64 



Mean. 



18-74 



511 



35*50 



40-55 



> 



Found. 





Cobalt, 



Hydrogen, 



Nitrogen, 



Oxygen, 



18-76 



5 04 



35-73 



18-72 



5-21 



35-50 



i 



18-75 



5-09 

 35-27 





315-0 100-00 



] 00 00 





As the nitrate of Xanthocobalt is, of all the salts of this base, 

 that which is most easily prepared in a state of purity, and as 

 its reactions are most characteristic of the base, we shall give 

 them ill this place. 



Chlorhydnc acid in excess gives a buff-yellow precipitate. 



Alkaline carbonates give no precipitate. 



Ferrocyanid of potassium precipitates beautiful orange-red 

 crystals. 



Ferridcyanid of potassium gives no precipitate. 



Cobaltidcyanid of potassium gives no precipitate. 



Chromate of potash gives a fine clear yellow precipitate- 

 Bichromate of potash gives beautiful orange-red needles. 



Oxalate of ammonia gives a voluminous precipitate of pale 

 yellow needles. 



Picrate of ammonia gives beautiful clear yellow needles. 



Phosphate of soda gives no precipitate. 



Pyrophosphate of soda gives no precipitate. 



Chlorid of mercury gives a bufl-colored scaly precipitate. 



Protochlorid of tin gives, after a short time, granular yellow 

 crystals. 



Bicblorid of platinum gives a orange-yellow precipitate. 

 Terchlorid of gold gives, after addition of chlorliydric acid 

 and standing, yellow needles. 



lodid and bromid of potassium give no precipitates, 



OXALATE OF XANTHOCOBALT. 



The oxalate of Xanthocobalt is precipitated when a solution 

 of oxalate of ammonia is added to one of the chlorid, nitrate or 

 sulphate of the base. After a very short time yellow acicular 

 crystals make their appearance, the separation being greatly fa- 

 cilitated by strongly agitating the solution. The precipitate is 

 to be thrown on a filter, well washed with cold water and dried, 

 first by pressure and afterwards in pleno over sulphuric acid. 

 As thus prepared, the salt has a pale yellow color, and consists 

 of fine needles, the form of which cannot be determined, even 



SECOND SERIES, VOL. XXIV, NO. 70. — JULY, 1857. 



13 





