128 
Mr. Chenevix on the Action of 
yet in this state it can draw down a greater quantity of the 
latter, than when it is merely poured into a mixed solution of 
platina, not before so treated. Indeed the whole of these 
experiments tend, not only to show that these two metals 
exercise a very powerful action upon each other, but that they 
are capable of great variation in the state of their combination ; 
and also that substances possessing different properties have 
resulted from my attempts to combine platina with mercury. 
This observation furnished me with a method of ascer- 
taining, or at least of approaching to the knowledge of, the 
quantity of mercury thus fixed by platina, and in combination 
with it. The experiment, however, having been seldom attended 
with full success, I mention the result with the entire consci- 
ousness of the uncertainty to which it is subject. I observed 
the increase of weight, which the original quantity of platina 
had acquired in some cases after it had been treated with 
mercury, and fused into a button. I counted that augmenta- 
tion as the quantity of mercury fixed. I then determined how 
much was precipitated by green sulphate of iron from a solu- 
tion of this alloy, and supposed it to contain the whole quantity 
of mercury found as above. But, even if attended with complete 
success, there is a chemical reason which must make us refuse 
our assent to this estimate. It is possible, and not unlikely, 
that a portion of mercury may be retained in solution by the 
platina, as well as that a portion of the platina may be preci- 
pitated by means of the mercury. The mean result, however, 
was that the precipitate by green sulphate of iron consisted of 
about 17 of mercury, and 83 of platina, when the specific 
gravity was about 16. 
With regard to palladium, lest it should be supposed that 
