we . 
W. Gibbs on the Platinum Metals ci 
the first place, the quantity of water required to dissolve out the 
soluble portions is very large, and the subsequent treatnient of 
such bulky solutions by distillation with acids, tedious—very 
large retorts being necessary. In the next place, it is impossible 
in this way to avoid exposure to the vapor of osmic acid, espe- 
cially in transferring the solutions from one vessel to another. I 
therefore prefer the following process which leaves nothing to be 
desired in point of safety or convenience. The fused mass is to 
e broken into pieces with a hammer and brought into a clean 
‘ iron pot—a common skillet with a long handle answers this pur- 
pose extremely well. Boiling water containing about one-tenth 
of its volume of strong alcohol is then to be added and the whole 
is to be boiled over an open fire until the fused mass is com- 
pletely disintegrated. The osmate of potash is in this manner 
reduced to osmite KOsO,, while the ruthenate of potash is com- 
pletely decomposed, the ruthenium being precipitated as a black 
powder—probably a mixture of RuO, and Ru,O, or of the hy- 
drates of these oxyds. It is advantageous, after boiling for some 
time, to pour off the supernatant liquid with the lighter portions 
of the oxyds and boil a second time with a fresh mixture of al- 
eohol and water. In this manner we obtain a solution of osmite 
cohol and introduced into a capacious retort. By this p 
when carefully executed, no trace of osmic acid esc 
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