on the Ammonia-cobalt Bases. 331 
__ fate of small granular crystals. These crystals are very insoluble 
*in cold water, but more readily soluble in boiling water acidu- 
lated with chlorhydric acid. Reducing agents separate gold 
with full metallic lustre. The formula of this salt is % 
6NHs.Co2zCls+AuCls 
as the analyses satisfactorily show: 
0°7308 grs, gave 01025 grs. CosO7 = 10°53 per cent cobalt. 
0°7308 grs. gave 02530 grs. Fae) = 8462 per cent. : 
06457 grs, gave 0-9714 grs. chlorid of silver = 37°36 per cent of chlorine. 
Eq: Calculated. Found, 
Cobalt, - 2 10°33 10°53 
OIG, se Lip 34°50 34°62 
Chlorine, - 6 37°30 87°36 
Todid of potassium produces immediately in solutions of the 
chlorid, sulphate, or nitrate of Luteocobalt, a remarkably beauti- 
ful b ight yellow precipitate of the iodid of Luteocobalt. This 
the ch] 
02224 grs. of this salt gave 0-06308 grs. sulphate of cobalt, corresponding to 
: 1079 per cent cobalt. 
The formula 6NHs.Co2Ts requires 10-88 per cent cobalt, 
._ rhe color of the precipitated and dried iodid is very fine, and 
ts brillianey led u¥ to hope that it might be advantageously em- 
lo} ed asa pigment. On trial, however, the color was found 
Wanting in body; the yellow, moreover, changes to a brown- 
yellow when the powder is ground in oil or water. 
BROMID OF LUTEOCOBALT. 
bromi - These crystals have the ym as those of the 
chlorid, and their formula is therefore 
: 6NHs.Co2Br:. 
COBALTIDCYANID OF LUTEOCOBALT. 
Os tideyanid of potassium produces in solutions of Luteo- 
: cobalt @ pal 
