OF PALLADIUM AND PLATINUM. 
307 
If we were disposed to consider that the principle which was found so remarkably 
displayed in the instance of the mercurial compounds held with platinum, and that 
in those instances where oxygen was present it should be looked upon as existing in 
the state of water, we might find here numerous additions to the class of metallic 
amidides ; thus the body C. should become, doubling the formula above written, 
PtCl 2 + 3 Pt Ad 2 + 8 HO, and similarly with the others. But it is exceedingly dif- 
ficult to say when Pt 0 2 and 2 Ad H act on one another, whether they unite directly, 
or whether they mutually decompose, forming Pt Ad 2 and 2 H O, which then unite ; 
this difficulty exists in all cases where the water cannot be separated without the sub- 
stance being completely decomposed. I would postpone for the moment the consi- 
deration of this point, and for the time at least look upon the hydrogen as being 
equally essential with the platinum as a constituent of these bodies. 
The formation of the first substance described requires no remark. I find that the 
same body may be produced by the action of dry ammoniacal gas upon chloride of 
platinum. There is absorbed about 11 or 12 per cent., indicating one equivalent, 
Pt Cl 2 -j- Ad H ; but if the current of gas be continued a white powder is obtained, 
formed by the union of two equivalents of ammonia to one of platinum, and which is 
identical with the muriatic salt of Gros, of which the formula may be simply written 
Pt Cl 2 + 2 Ad H. 
It is evident that the body B. cannot be produced directly from the perchloride of 
platinum, as that does not contain the quantity of chlorine necessary for its constitu- 
tion, and indeed, if we examine the ammoniacal liquor from the first commencement 
of the formation of the fawn-coloured substance, it will yield the body D. on the ad- 
dition of alcohol. I consider therefore these two bodies as being of simultaneous 
origin, there being formed from 
3 Pt C'l 2 with 4 Ad H and 7 H O 
Pt 2 Cl 5 Ad 2 H 7 0 4 and Pt Cl Ad 2 H 4 0 3 . 
From the fawn-coloured substance B., the brown body C. may be simply formed, 
four equivalents of muriatic acid being removed, and one of ammonia given in their 
place. This is not equivalent substitution, but it still shows the origin of the body. 
If, however, the fawn-coloured substance all passed through the brown condition, the 
quantity of this last generated should, I consider, be much greater than it actually is 
found to be, and hence I am inclined to consider that 
From two atoms of B. . . Pt 4 Cl 10 Ad 4 H 14 O g 4 
And ten atoms of ammonia Ad 10 H 10 J 14 10 C 14 24 8 
there are formed 
One atom of C. . . 
Two of Gros’s base dry 
Seven of sal-ammoniac . 
Pt Cl Ad 3 H 4 0 4 a 
Pt 2 Cl 2 Ad 4 H 8 0 4 > Pt 4 Cl 10 Ad 14 H 2l O g . 
Cl.Ad 7 H 14 J 
2 r 2 
