AMMONIA-COBALT BASES. 37 



0.7305 grs. gave 200.5 c. c. of nitrogen at 21°.5 C. and 765""".80 (t = 22°.2 C.) = 182.3 c. c. 



at 0° aud 760 mm = 31.34 per cent, nitrogen. 

 0.1773 grs. gave 212 c. c. of nitrogen at 18° C. and 762 mm .75 (t = 18°. 6 C.) = 194.94 c. c. 

 at 0° and 760""" = 31.49 per cent, nitrogen. 



Comparing these with the calculated results, we have 



Eqs. Theory. Mean. Found. 



Cobalt . . 2 59.0 22.06 22 05 22.05 22.01 22.11 22.02 



Chlorine . 3 106.5 39.79 39.73 39.68 39.78 — — 



Hydrogen . 18 18.0 6.73 6.70 6.68 6.73 — — 



Nitrogen . 6 84.0 31.42 31.41 31.49 31.34 _ _ 



267.5 100.00 99.89 



The formula 6NH 3 .Co 2 Cl 3 is given, by both Fremy and Rogojski, and no 

 reasonable doubt can be entertained of its accuracy. The density of the chloride 

 of Luteocobalt, as taken in alcohol, is 1.7016 at 20° C, its atomic volume is con- 

 sequently 157.2. 



The reactions of the chloride of Luteocobalt are as follows : 



Iodide of potassium gives a bright yellow precipitate. 



Bromide of potassium gives a less brilliant yellow precipitate. 



Ferrocyanide of potassium gives a chamois colored precipitate, which becomes 

 black on boiling. 



Ferridcyanide of potassium gives beautiful yellow needles, which are nearly 

 insoluble. 



Cobaltidcyanide of potassium gives a pale fawn colored precipitate of fine needles. 



Terchloride of gold gives bright yellow granular crystals of the chloraurate. 



Bichloride of platinum gives yellow or orange-yellow needles of the chlor- 

 platinate. 



Chromate of potash gives a bright yellow precipitate of the chromate. 



Oxalate of ammonia gives a buff yellow precipitate, soluble in oxalic acid. 



Tribasic phosphate of soda gives, after a short time, a yellow precipitate. 



Pyrophosphate of soda gives a pale buff colored precipitate. 



Picrate of ammonia gives a beautiful yellow precipitate of very fine silky 

 needles. 



Alkalies and their carbonates produce no precipitate in the cold. 



Sulphide of ammonium gives a black precipitate. 



CHLORPLATINATE OP LUTEOCOBALT. 



Chloride of platinum produces, immediately, in a solution of the chloride of 

 Luteocobalt, a beautiful orange or yellow precipitate of the chlorplatinate. When 

 the solutions employed are concentrated, the precipitate is orange colored; when 

 the solutions are dilute, yellow needles are thrown down. The difference is here 

 only in the quantity of water of crystallization, and the orange granular crystals 

 may be converted into the pale yellow needles by solution in a large quantity of 

 hot water and recrystallization. 



