412 Mr. Tennant on two Metals, found in the Powder 
that it contains also another metal, different from any hitherto 
known. 
The substance with which my experiments were made, was 
obtained from platina which had been previously freed from 
the sand and other impurities generally mixed with it ; so that 
it must have been contained in the substance of the grains 
of platina. Though it has somewhat the appearance of plum- 
bago, it may easily be distinguished by its superior weight. 
By weighing it in a phial with water, I found its specific gravity 
almost 10.7. 
Before I describe the method of separating the two metals of 
which it consists, it may be worth while to mention the effects 
of it, when combined with different metals in its entire state. 
It readily unites with lead ; but, even with ten times its own 
weight, the compound has not, when melted, much fluidity. 
Upon dissolving the lead in nitrous acid, the black powder was 
obtained, with little apparent alteration, not having been entirely 
broken down, but consisting chiefly of the same scaly particles 
as at first. With bismuth, zinc, and tin, the effects were nearly 
similar; but, by fusion with copper in a very strong heat, a 
more perfect union was produced. On attempting to dissolve 
the compound by nitro-muriatic acid, some of the powder 
was taken up with the copper, forming a very dark , solu- 
tion. 
The undissolved portion consisted partly of the substance in 
its original form of scales, and partly of a blacker powder, the 
particles of which were too small to be visible, and which had 
probably been completely combined with the copper. This 
substance may be easily united, by fusion, with silver or gold ; 
and it is particularly deserving of attention, that it cannot be 
