193 W. Gibbs on the Hexatomic compounds of Cobalt. 
gentle heat to half its volume. On cooling, a small quantity of 
Fischer’s salt Co.(NO.)2K,+2OH, separated ; afterward sherry- 
wine colored prismatic crystals were formed in abundance. 
After recrystallization these were analyzed. 
0°2824 gr. gave 0°1519 gr. CoOSO,=20°47 per cent cobalt. 
0°5557 gr. gave 0°2092 gr. silver=12°37 per cent chlorine. 
The same experiment was made with sodic nitrite, and with 
similar results. After two recrystallizations the salt formed 
zed. 
04163 gr. gave 0°2235 gr. CoSO,—20°43 per cent cobalt. 
0°2332 gr. gave 0°0876 gr. silver=12°38 per cent chlorine. 
0°6625 gr. gave 192-12 ¢.c, nitrogen (moist) at 14° C. and 764°™°1 
=34°29 per cent. 
1°2310 gr. gave 0°5825 gr. water=5°24 per cent hydrogen. 
16542 gr. gave 0°7996 gr. water==5°37 per cent hydrogen. 
The salt being found anhydrous, the analyses agree with the 
formula : 
Co,(NH;) ,.(NO2)2(NO5)2Cl., 
which requires 
Cobalt 20°52 20°47 20°43 
Chlorine - 12°34 12°37 12°38 
Hydrogen 5°26 5°24 89537 
Nitrogen 34-09 34°29 
and which is fully sustained by other considerations, as I shall 
show. As the solutions of the alkaline nitrites employed also 
contained nitrates, the formation of the new salt may be repre- 
sented by the equation: 
Co,(NH,), Clo-+2KNO,+2KNO,=4KCI+Co,(NH;);o 
(NOz)2(NO3)2Cl.. 
cobalt series, but crystallizes usually in prismatic forms, whic 
are moderately soluble in hot water, and separate readily from 
the solution. With neutral potassic chromate the salt gives 
the beautiful yellow crystalline chromate of xanthocobalt : 
Co,(NH,) ,4(NO;)9(Cr0,)+20H,. 
With potassic ferrocyanide it gives the characteristic red pris- 
matic crystals of 
_ Co,(NH;),,(NO,)2FeCy,+60H,, 
and with ammonic oxalate, oxalate of xanthocobalt, 
Co,(NH3)19(NO2)2(C294) 2, 
