Platina and Mercury upon each other. 125 
button which results from the operation, is generally more 
considerable. 
Exper. 5. If sulphur be rubbed for some time with aramo- 
niacal muriate of platina, and the mixture be introduced into a 
small Florence flask, it can be melted on a sand-bath. If 
mercury be then thrown into it, and the whole be well stirred 
together and heated, it may afterwards be exposed to a very 
strong fire and melted into a button. If this be dissolved in 
nitro-muriatic acid, it will give a precipitate, as in the former 
cases, by green sulphate of iron. 
Exper. 6 . If a current of sulphuretted hydrogen gas be sent 
through a mixed solution of platina and mercury, and the 
precipitate which ensues be collected, the metal may be re- 
duced by heat ; and with the addition of borax, it may be 
melted into a button which will not contain any sulphur. Green 
sulphate of iron causes a precipitate in the solution of this 
metal also. 
Exper. 7. If to a mixed solution of platina and mercury, 
phosphate of ammonia be added, a precipitate takes place. If 
this be collected and reduced, it will be acted upon by green 
sulphate of iron poured into its solution, in the same manner as 
the metallic buttons .11 the preceding examples. 
Exper. 8. I have already mentioned that when a solution of 
nitrate of mercury, at the minimum of oxidizement,is poured into 
a solution of muriate of platina, a mercurial muriate of platina is 
precipitated. The supernatant liquor may be decanted and the 
residuum washed ; if this be reduced and afterwards dissolved 
in nitro-muriatic acid, it will yield a precipitate with green' 
sulphate of iron. This method appears to me to be the neatest 
for combining platina and mercury, as the action which takes 
