s 
on the Ammonia-cobalt Bases. 327 
_ decomposition of a complex molecule are more simple in consti- 
tution than the body decomposed. 
Luteocobalt, like Robeptattalt is a triacid base. 
CHLORID OF LUTEOCOBALT. 
cote crystals, which are the chlorid of Luteocobalt. _Chlor- 
easily purified by solution in hot water, filtration, and repeate 
crystallization. ‘This method of preparing the salt is by no 
means always successful, and very frequently results only in the 
formation of chlorid of Roseocobalt and Purpureocobalt, with 
scarcely a trace of the chlorid of Luteocobalt. We have, how- 
ever, almost invariably succeeded in preparing, by this process, 
4 mixture of the sulphate and chlorid of Luteocobalt, by em- - 
Ploying a solution containing both the chlorid and sulphate of 
alt. The sulphato-chlorid resulting, by boiling with chlor- 
hydric acid and chlorid of barium, yields a solution from which 
the pure chlorid may be obtained by repeated crystallization. 
The chlorid of Luteocobalt crystallizes by slow evaporation, 1n 
Prof. Dana, the usual forms are, in his modification of Naumann’s 
notation, O, a, i, O-3, 1-&, 3- é, with the angle Paes =3113° 
16. Fig 9 represents a crystal of this salt with Dana’s notation 
for the faces - 
9. 
1:I = 113° 16’, 
 O:14 = 145° 557, 
ver O) 
= 5 (over O) | 
8%: 3 = 127° 34? (adjacent) 
== 118° 35’ (by observation) 
Frém states that this salt crystallizes in regubar octahedrons ; 
this pfs it wae be Sinorphouk but we have never observed 
*ny forms belonging to the regular system. 
~ 
2 
