W. Gibbs on the Hexatomic compounds of Cobalt. 199 
the reactions being too obvious to require explanation by equa- 
ions. 
c : 
beautiful prismatic forms. In this case we have 
Co,(NH;) 10 (NO,),Cl,+Co,(NH,) 1 o(NO,),(NO;),=2Co, 
(NH) 1 o(NO, )o(NO,)2Cl. 
Of the crystals so formed 
0°6203 gr. gave 0°3310 gr. CoSO,=20°31 per cent cobalt. 
0-9268 gr. gave 0°3450 gr. silver=12°24 per cent chlorine. 
The formula requires 20°51 per cent cobalt and 12°34 per cent 
chlorine. A portion of the crystallized salt was dissolved and 
precipitated by argentic nitrate. The filtrate from AgCl gave 
on evaporation crystals of nitrate of xanthocobalt, in which 
0°2972 gr. gave 071469 gr. CoSO,—18°81 per cent cobalt. 
The formula of the nitrate requires 18°73 per cent. These re- 
sults leave no doubt as to the constitution and true relations of 
the chloro-nitrate. dat 
id salt—When the chloro-nitrate is dissolved and a solu- 
tion of aurochloride of sodium, AuCl,Na, is added in excess, 
ong prismatic wine-yellow crystals are formed. Of these 
crystals 
0°8564 gr. decomposed by zine and sulphuric acid gave 0°6300 gr. 
silver=24°16 vas cent chlorine and 0°2858 gr. gold=33°36 per 
ce 
nt. F 
0°4084 or. gave 0°1770 gr. Au+Co=43'34 per cent and by dif- 
ference 9°98 per cent cobalt. 
This formula, Co.(NHg)o(N Oz)(NOs)Cl,+2AuCls, requires 
: Found. 
Cobalt 9°98 9°98 
G 
0 . 
Chlorine 24°03 24°16 
The salt is readily decomposed by boiling with reduction of 
metallic gol ol ie g 
Platinum salt.—Platinic chloride in solution precipitates the 
chloro-nitrate almost immediately in the form of wine- wai 
needles. After recrystallization this salt was analyzed wit 
the following results : ; 
