258 W. Gibbs and F. A. Genth 
cobalt are also formed im great abundance by the action of acids 
upon salts of Xanthocobalt, and we are disposed to think that 
they may also occur, though rarely, among the products of the 
decomposition of salts of Luteocobalt. 
The salts of Purpureocobalt are distinguished by a fine violet- 
red or purple color, which is common to nearly all of them, and 
which is very different from the comparatively dull red of the 
salts of Roseocobalt. They are in general somewhat less soluble 
than the compounds of Roseocobalt, and crystallize, for the most 
part, in well defined crystals. When neutral they have a purely 
saline, non-metallic taste. ° 
Heat readily decomposes the salts of this base; the final pro- 
ducts of the decomposition are the same as in the case of the 
salts of Roseocobalt, but intermediate products are often form 
The neutral solutions are readily decomposed by boiling, the 
products of the decomposition being a black or dark-brown 
oxyd of cobalt and a salt of ammonium, free ammonia being 
given off. In some cases, however, salts of Luteocobalt are in- 
termediate products of this decomposition. 
All the salts of Purpureocobalt tylong boiling with an excess 
d. 
of chlorhydric acid yield the chlorid. 
CHLORID OF PURPUREOCOBALT. 
The substance which we shall describe under the name of 
fore, necessary to devise a new name. The purple color of the 
salts which correspond to the chlorid now to be describe 
us to adopt the name of Purpureocobalt for the radical of these 
salts, as more appropriate than Roseocobalt, which we have te 
tained for most of the salts to which it was originally applied. 
Such a change is to be regretted; it could not, however, have 
been avoided, without an introduction of two entirely new 
names. 
We have already stated that the chlorid of Purpureocobalt 18 
often a product of the direct oxydation of an ammoniacal solu- 
tion of the chlorid of cobalt exposed to the air. In these cases 
that the temperature at which the process of oxydation goes OP 
is the condition which determines the character and the amount 
a. t is, in our view, the first product of the 
oxydation under all circumstances. Ata moderately high tem- 
