292 W. Gibbs on the Hexatomic compounds of Cobalt. 
Auro-chloride of purpureocobalt_—When a solution of chloro- 
aurate of sodium is added to a hot solution of chloride of pur- 
pureocobalt, containing a little free chlorhydric acid, no pre- 
cipitate is formed at first, but after standing a few hours 
erystals of a new salt are depusited. The crystals in question 
present flat prismatic forms. They have a dark ruby-red color, 
with a dull violet luster, and after standing, exhibit a distinct 
superficial reduction of gold. Of these crystals 
09028 gr. gave 0°3206 gr. gold, and 1°0560 gr. silver=35°50 per 
cent gold, and 38°45 per cent chlorine. 
0°6840 gr. gave 0°1896 gr. SO,Co and 0°2425 gr. gold=10°55 per 
cent cobalt, and 35°45 per cent gold. 
Calculated. Found. 
Cobalt, 2 10°64 10°55 
Gold, 2 35°55 35°50 85°45 
Chlorine, 12 38°44 38°45 
Co,(NH,),,Cl,+2AuCl,, 
or rationally 
From the formula it appears that the salt is unsaturated, simi- 
lar salts containing 4 or 6 molecules of auric chloride being also 
possible. 
water, especially in the presence of free chlorhydric acid, and 
—— crystallizing from the hot solution. This salt has the 
ormula 
: Co,(NH;,),,Cl, +6HgCl, 
as the following analyses show: 
0°5884 gr. gave 0°3922 gr. Hg, Cl,—=56°60 per cent mercury. 
0°4409 gr. gave 0°4025 gr. silver *=30-00 oe cent chlorine. 
‘< ; gone Found. 
ercury, 56°4 56°60 
Chlorine, 18 30°04 30°00 
