252 W. Gibbs and F. A: Genth 
When nitrate of Roseocobalt is dissolved in water containing 
much nitrate of ammonia and a little ammonia, and the solution 
is allowed to evaporate spontaneously, beautiful purple-red scaly . 
crystals separate. These crystals cannot be purified by recrys- 
tallization, as they are decomposed by solution in water. When 
boiled with chlorhydric acid there is copious effervescence and a 
purple-red solution is obtained, which appears to contain the 
chlorid of Purpureocobalt. The empirical formula of the scaly 
nitrate appears to be 5NHs.CozO2, 2NOs+7HO. From -the 
effervescence with muriatic acid we are disposed to consider it 
4NHs3 .Co20s, NO; +NH:0, NO; +6HO, but further investi a 
tion is required before we can pronounce with certainty on this 
point. 
HYDROUS NITRATE OF ROSEOCOBALT. 
When ammonia is added in excess to a solution of the nitrates 
of cobalt and of ammonia and the solution is exposed to the air, 
oxydation takes place with considerable rapidity, and as we have 
already stated when speaking of the anhydrous nitrate, the so- 
lution becomes dark purple-red, while yellow scales of the nitrate 
of Luteocobalt are more or less abundantly deposited upon the 
bottom of the vessel. When the red liquid is boiled with nitric 
acid in excess, a dark crimson precipitate of nitrate of Roseoco- 
balt is formed, while a portion of the same salt remains in solu- 
tion. It has hitherto been supposed from these facts that the 
anhydrous nitrate of Roseocobalt is a direct product of the oxyd- 
ation of the ammoniacal liquid, This, however, is not the case. 
If the oxydized liquid be filtered from the nitrate of Luteocobalt 
and allowed to evaporate spontaneously, very fine large oblique 
rhombic crystals are formed, which are the hydrous nitrate of 
Roseocobalt. 
The crystals of this nitrate belong to the monoclinic or sae 
rhombic system, according to Prof. Dana’s determination. € 
observed forms are J, 14, 22, —12, 72, or in other symbols, «, 1-© 
G- 00, —1- 00, co-o. Hig. 7. Th 
y 
: 6 
14:4 == 140° 30’ 
li:1i = 96° 30’ and 838° 30’ 
The hydrous nitrate of Roseocobalt is readily soluble even 0 
cold water; the hot neutral solution is very — decom: 
evolution of ammonia and precipitation of a black powder. 
The addition of a few drops of nitric acid prevents the decom- 
tion. An excess of nitric aci toa “cold solution of 
nitrate produces a brick-red precipitate, which is readily sol 
