on the Ammonia-cobalt Bases. 321 
The oxalate is nearly insoluble in cold water, and not = 
soluble in boiling water, even after ‘addition of free oxalic aci 
Owever, in one or two experiments made for the purpose 
ACID SULPHATE OF PURPUREOCOBALT, *® 
? . _ Our efforts to obtain a neutral sulphate of Purpureocobalt 
| containing two equivalents only of sulphuric acid have hitherto. 
Seen fruitless. hen a solution of chlorid of Purpureocobalt 
18 treated with sulphate of silver, chlorid of silver is formed, and 
| the red supernatant liquid yields, on evaporation, crystals of sul- 
Phate of Basbasdtials Precisel 
double decomposition, but that during evaporation the equiva- 
lent of free sulphuric or nitric acid formed at the same time with 
the sulphate or nitrate, reacts upon this so as to convert it into 
1 4 salt of Roseocobalt with three equivalents of acid. In equa- 
| _—_ ons we should have for the sulphate 
_ 5NHs.Co2Cls--3Ag0, S0s+-HO =5NHs.00s0s, 38004-HO, SOs 
3AgCl. 
5NH3.Co20s, 290s-4-HO, SOs=5NHs .Co20s, 380s-++ HO. 
. When oil of vitriol is poured upon chlorid of Purpureocobalt 
i quantity sufficient to make a thick paste, the mass assumes a 
. of tiful violet-red needles is deposited. The mother 7 
. after standing for a longer time, deposits crystals. Ti ad 
gra are to be quickly washed with a little cold water, drain 
ied b 
ba : 
acid sulphate together with small quantities of another 
i i fully hereafter, and 
which we describe more ys ire, yall 
