58 RESEARCHES ON THE 



Nitrate of Xanthocobalt has the formula 



N0 2 .5NH 3 .Co 2 3 ,2NO a +HO 



as the following analyses appear to show : 



0.391Y grs. gave 0.1921 grs. sulphate of cobalt = 18.12 per cent, cobalt. 



0.6960 grs. gave 0.3405 grs. " " = 18.16 " 



0.5935 grs. gave 0.2925 grs. " " = 18.15 " " 



0.5585 grs. gave 0.2535 grs. water = 5.04 " hydrogen. 



0.4958 grs. gave 0.2330 grs. " = 5.21 " 



0.9483 grs. gave 0.4210 grs. " = 5.09 " " 



0.6145 grs. gave 181.45 c. c. nitrogen at 6°.5 C, and 769 mm .5 (at 1° C), (h = 35"" n .O) = 114.55 



c. c. at 0° and 160"' m = 35.13 per cent. 

 0.6024 grs. gave 183.30 c. c. of nitrogen at 5° C, and Y59 mra .O (at 6° O), (h = 31 ra,n .O) = 169.20 



c. c. at 0°and 160 mm = 35.21 per cent. 

 0.5912 grs. gave 184.66 c. c. nitrogen at 11°.5 C, and T61 mm .O (at 12° C), (h = 32""".5) = 167.13 



c. c. at 0° and 160 mm = 35.50 per cent. 



Hence we have 



Eqs. Calculated. Mean. Found. 



Cobalt . 2 59.0 18.13 18.14 18.16 18.12 18.15 



Hydrogen 16 16.0 5.08 5.11 5.04 5.21 5.09 



Nitrogen . 8 . 112.0 35.55 35.50 35.13 35.50 35.21 



Oxygen . 16 128.0 40.64 40.65 — — _ 



315.0 100.00 100.00 



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 charac- 

 teristic of the base, we shall give them in this place. 



Chlorhydric acid in excess gives a buff-yellow precipitate. 



Alkaline carbonates give no precipitate. 



Ferrocyanide of potassium precipitates beautiful orange-red crystals. 



Ferridcyanide of potassium gives no precipitate. 



Cobaltidcyanide 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. 



P}n*ophosphate of soda gives no precipitate. 



Chloride of mercury gives a buff-colored scaly precipitate. 



Protochloride of tin gives, after a short time, granular yellow crystals. 



Bichloride of platinum gives an orange-yellow precipitate. 



Terchloride of gold gives, after addition of chlorhydric acid and standing, yel- 

 low needles. 



Iodide and bromide of potassium give no precipitates. 



