320 W. Gibbs and F. A. Genth 
formula, with the exception of the hydrogen, which he makes 
16 in place of 15 equivalents. We have also obtained it from 
a chlorid which gave the reactions of chlorid of Roseocobalt, 
but we must leave it for the present undecided whether in this 
case there bs a my See of Roseocobalt into = anaes 
5NH:3.Coe2C1.Clz eas 
We shall pe this view Hits fully when speaking of the 
oxygen salts of Purpureocob 
OXALATE OF PURPUREOCOBALT. 
This most beautiful sus is readily prepared Py adding a solu- 
tion of oxalate of ammonia to one of chlorid of Purpureocobalt. 
After a short time violet- er needles are thrown down, which 
may be washed with cold water. As thus prepared, the salt is 
almost chemically pure. The color of the oxalate of Purpured- 
cobalt is the violet ,%, of the first circle of Chevreul’s scale; the 
crystals are not sensibly dichrous. We have not, as yet, ob tained 
measurable crystals of this salt. Under the microscope four- 
and six-sided acicular prisms are distinguishable, but without 
characterizing terminal planes. 
The oxalate of Purpureocobalt has the formula 
5NH:.Co20s, 2C203+3HO 
as the following analyses show: 
O2723 gave - 574 ors. sulphate of cobalt = = 22-00 per, cent of cobalt, 
0°8970 gre. gr buat wit with th oxy of copper gave 0:2973 78 gre. carbonic acid = 27'11 per 
The formula requires 
Eqs. Caleulated. _ Found. 
Oey ect. 22-09 $200 21°95 
(Oxalicacid, - - 3 26-96 2711 0 
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