on the Ammonia-cobalt Bases. 245 
however, consist in the mere loss of water. As we shall show, 
the chlorid of Roseocobalt corresponds to a triacid oxyd, while 
that of Purpureocobalt yields a biacid oxyd. It is to be ecare- 
fully borne in mind, that the substance which we have called 
chlorid of Roseocobalt is not the chlorid of Roseo-cobaltiaque of 
Frémy, Claudet, and other chemists who have studied the sub- 
ject. To the chlorid described by Frémy under the name of 
chlorid of Roseocobaltiaque we have given the name of chlorid 
of Purpureocobalt. The necessity of this change of name has 
arisen from the fact that hitherto two different bases have been 
confounded, the chlorid of Purpureocobalt having been consid- 
ered as the chlorid corresponding to the sulphate and nitrate of 
ocobalt. 
The chlorid of Roseocobalt is dichrous, the ordinary being 
paler than the extraordinary image; both are rose-red, with a 
nt brownish orange tint. 
Chlorid of Roseocobalt, as already mentioned, has the formula 
5NHs3.Coz Cls +2HO, 
as the following analyses show: 
07291 prs. gave 0:4235 grs, of sulphate of cobalt = ne . per eent of cobalt. 
06247 grs, gave 03619 grs. « i 
09884 gra. gave 05742 grs. chlorid of silver == 39 57 chlorine, 
18112 grs, gave 29095 ors,“ . =e. « hyd 
2890 grs. gave 1 2829 grs. water ae eet ‘s tbr 
¢ = 650 
12235 grs, gave 282 e. c. nitrogen at 22°5 C. and 766””82 (at 23° C.) = 254°91 
c. c. at 0° and 760”™ == 26°16 per cent. 
The formula requires— 
Calculated. Found. ‘ 
Cobalt, -..--:-3 QUST 21°99 22°10 
Chlorine, -  - 39°66 3957 = 389-71 
Hydrogen, - 6°38 637 650 
Nitrogen, - - 26°0 26°16 age 
Wit ct to this formula, it must be remarked that it is 
extremely difficult to obtain this chlorid perfectly free from chlo- 
nd of Purpureocobalt, into which it is so easily converted. 1 he 
Uncertainty, however, will concern only the number of equiva- 
lents of water. The chlorid of Roseocobalt combines with the 
chlorids of the electro-negative metals to form well defined salts, 
€ platinum salt, which we have not yet fully examined, ap- 
Pears to have the formula 
5NHs.Co2Cl3+8PtCl: +8HO. 
Ps neutral solution of the chlorid A Roseocobalt . ae 
a ili ith evolution of ammonia, an - 
tou of a block noncien This powder is probably a hydrate of 
the magnetic oxyd, Cos0s+2HO, but we have idaleneeih its ex- 
