242 W. Gibbs and F. A. Genth 
protoxyd of cobalt, but the particular cireumstances, which ae- 
company the formation of each one, will be best considered in 
treating of the separate compounds. Roseocobalt is a triacid base. 
CHLORID OF ROSEOCOBALT. 
process; a large quantity of this salt in the solution often gives 
a lilae or purple precipitate as the oxydation advances, but this 
is composed principally of the chlorid of Purpureocobalt. As 
will be seen from the above, the chlorid of Roseocobalt is not 
always formed during the oxydation of an ammoniacal solution 
of chlorid of cobalt. On the contrary, it often happens that not 
@ trace of this salt can be obtained from the oxvdized solution, 
which contains only the chlorid of Purpureocobalt, We have 
observed the absence of the chlorid of Roseocobalt only in soln- 
tions which had been oxydized in a warm room, or during t 
summer season. This fact, taken in connection with the facility 
with which heat transformes solutions of Roseocobalt into those 
of Purpureoeobalt, renders it, to say the least, extremely proba- 
ble, either that a comparatively high temperature prevents the 
formation of the chlorid huseeeobalt entirely, or else that this 
salt is converted into chlorid of Purpureocobalt as fast as3t1s 
formed in the solution, ia 
