Action of Viatina and Mercury upon each other. ro3 



gusts. Our philosophical Indian travelled in a canoe, but 

 met with no less than seventy-six carrying-places in the 

 course of his long journey. 



[To be continued.] 



XVI. On the Action of Platina and Mercury upon each 

 other. By Kichaud Chenevix, Esq. F.R.S. M.R.LA. 



&c. 



[Concluded from p. 35.] 



Xt is my intention now to exhibit one example of my po- 

 sition, and to prove that platina and mercury act upon each 

 other in such a manner as to disguise the properties ot" both. 

 I shall therefore waive for the present all consideration of 

 palladium, which is in fact but a subordinate instance of 

 tJie case before us. 



When a solution of green sulphate of iron is poured into 

 a solution of platina, no precipitate nor any other sensible 

 change ensues. This I had already observed, and it has 

 since been confirmed by all who have written upon the 

 subject- But, if a solution of silver or of mercury be added, 

 a copious precipitate takes place. This precipitate contains 

 metallic platina and metallic silver or mercury ; some mu- 

 riate of one or other of the latter metals is also present, as 

 it is not easy to free the solution of platina from all super- 

 fluous muriatic acid. But these salts are of no in)portance 

 in the experiment, and can be separated by such methods 

 .1" a kuo-.vledge of their chemical properties will easily sug- 

 gest. 7'he proper object of consideration i.s the reduction 

 of the plaiina to the metallic state, which docs not happen 

 when it is alone. I have tried to produce the same eflect 

 with other metals and platina, but I have not observed any 

 thing similar. It is therefore fair to conclude, that when 

 a solution of platina is precipitated in a metallic state by a 

 solution of green sulphate of iron, either silver or mercury 

 is present. 



The preci(<itation of a mixed solution of platina and silver 

 requires no further caution than to free the salt of platina 

 as much as jiossiblc from muriatic acid ; for, as I observed 

 in my former paper, the eflect of nitrate of silver poured 

 into muriate of platina, is to produce a precipitate, not of 

 muriate of silver, but of a triple muriate of platina and 

 silver. It was by this experiment that I then proved the 

 aflinilv of these two metals ; for, when silver is not present, 

 O 4 muriate 



