36 



RESEARCHES ON THE 



with the angle 1:1 = 113°. 16'. Fig. 9 represents a crystal of this salt with 

 Dana's notation for the faces : 



Fig. 9. 

 1:1= 113° 16' 3* : 3* = 52° 26' (over 0) 



0:1*= 145° 55' 3i : 31 = 121° 34' (adjacent) 



O : 3t = 116° 13' : } = 118° 35' (by observation) 



11 : 1* = 112° 2' (over 0) 



Fremy states that this salt crystallizes in regular octahedrons ; in this case it 

 must be dimorphous, but we have never observed any forms belonging to the 

 regular system. 



The chloride of Luteocobalt is readily soluble in boiling water, and crystallizes 

 in a great measure from the solution on cooling. Chlorhydric acid and alkaline 

 chlorides precipitate it unchanged. When boiled with sulphuric acid, the salt 

 gives off abundance of chlorhydric acid gas, but it is difficult to drive off all the acid 

 without decomposing a portion of the resulting sulphate. The salt is slowly decom- 

 posed by boiling ammonia, chloride of ammonium, and a dark brown oxide of cobalt 

 being the only products of the decomposition which we have been able to detect. 

 Reducing agents in general act upon this salt as upon chloride of Roseocobalt 

 and Purpureocobalt. We have not yet, however, been able to obtain with the 

 chloride of Luteocobalt compounds analogous to those which are produced by the 

 action of sulphurous acid and deutoxide of nitrogen upon the chlorides of Eoseo- 

 cobalt and Purpureocobalt, although we have repeatedly made the attempt. 



The chloride of Luteocobalt is dichrous. In the dichroscopic lens the ordinary 

 image is pale violet, while the extraordinary image is orange-violet. The color of 

 the salt, in coarse powder, approaches the orange-yellow of the first circle, but the 

 color of the mass of crystals could not be defined by the chromatic scale, which 

 we employed. Chloride of Luteocobalt exhibits a remarkable tendency to form 

 chloro-salts with metallic chlorides. These salts are formed with great ease, by 

 the direct union of the two chlorides, and are worthy of notice for their stability 

 and capacity of crystallization. Of these salts, which are very numerous, we have 

 examined only the compounds with gold and platinum. 



The analyses of chloride of Luteocobalt lead to the formula 



6NH 3 .Co 2 Cl 3 , 



0.2036 grs. gave 0.1180 grs. sulphate of cobalt = 22.05 per cent, cobalt. 



0.3350 grs. gave 0.1938 grs. " " = 22.01 



0.5110 grs. gave 0.2910 grs. " " =22.11 



0.3335 grs. gave 0.1930 grs. " " =22.02 



0.2942 grs. gave 0.4723 grs. chloride of silver = 39.67 " chlorine. 



0.4886 grs, gave 0.7846 grs. " " = 39.78 



0.3902 grs. gave 0.2346 grs. water = 6.68 " hydrogen. 



0.4617 grs, gave 0.2800 grs. " = 6.73 



