58 W. Gibbs on the Platinum metals. 
crystallizes from the solution, on cooling, in beautiful orange-yel- 
ow granular crystals. The formula of this salt is 6NH,.Co, 
Cl,+38PdCl. Any traces of palladium which may have been 
present in the original mass of double chlorids will therefore be 
found with the ruthenium and platinum salts. When the mixed 
chlorids have been thoroughly washed, palladium is never pres 
The sesquichlorid of ruthenium gives no precipitate with 
solutions of chlorid of luteocobalt, and appears not to form a 
double salt with the chlorid of this radical, possibly in conse- 
quence of the ¢riacid character of luteocobalt and the bibasic — 
character of the sesquichlorid of ruthenium, the potassium — 
double salt being Ru,Cl,+2KCl. All the sesquichlorid of — 
ruthenium present in the mass of mixed chlorids in combination 
with chlorid of potassium will therefore be found in the filtrate 
from the insoluble iridium and rhodium double salts. 
rated to dryness and the chlorid of cobalt dissolved out by boiling — 
with absolute alcohol. The iridium and rhodium are then to be — 
nearly to dryness, boiled with a strong solution of caustic potasb, 
and then treated with an excess of chlorhydric acid, which gives — 
the double chlorids RuCl, KCl, PtCl, KCl and Ru,Cl, 2KCl, — 
together with an excess of chlorid of potassium and a little — 
chlorid of cobalt. This last may easily be removed by alcohol — 
after evaporating the mixed chlorids to dryness. Platinum and | 
ruthenium may then be separated by boiling with nitrite of :. 
potash, evaporating to dryness, boiling with dilute chlorhydri¢ , 
acid so as to convert the whole of the ruthenium into RuCl, — 
KCl, neutralizing with carbonate of potash, again boiling with — 
nitrite of potash, evaporating to dryness and dissolving out the — 
€ nitrite of ruthenium and potash by absolute alcohol. — 
j 
Be 
Sian 
