OF PALLADIUM AND PLATINUM. 
303 
sent moment noticed. It may be considered as the ordinary double chloride of am- 
monium and platinum, Pt Cl -j- N H Cl, united to a compound of chloride of plati- 
num and oxide of ammonium, and then two atoms of water added. Thus 
Pt . Cl 2 + N H, Cl 
Pt . Cl 2 + N H 4 O J T " 1 
— Pt 2 Cl 5 N 2 H 10 o 3 . 
Whether this be its true constitution will be discussed in the sequel. 
It may be also composed of the chloride of platinum and ammonium united to the 
body described in paragraph A. and to water. Thus 
Pt Cl 2 + NH 4 Cl A 
PtCl 2 + NH 3 > = Pt 2 Cl 5 N 2 H n 0 4 . 
h 4 o 4 J 
This is a more likely supposition than the former. 
C. When the fawn-coloured substance last described is continually boiled in 
water of ammonia, it ultimately dissolves, but it may be observed to become dark 
brown before it disappears. This brown substance dissolves almost as soon as formed, 
and hence it is difficult to obtain a quantity of it for analysis ; even a large quantity 
of chloride of platinum yielding by the action of ammonia only traces of it. This 
brown powder is not acted on by boiling water. With muriatic acid, it partly dis- 
solves, giving a yellow liquor, and is partly converted into a white powder, sparingly 
soluble in water. 
When heated it gives off sal-ammoniac, water and nitrogen, and metallic platinum 
remains. To determine the composition of this substance the same methods of ana- 
lysis were used as in the former cases. 
2T608 grains ignited with carbonate of soda, gave 13-455 of platinum, or 61-80 
per cent., and then 9-939 of chloride of silver, corresponding to 11-35 of chlorine in 
100 . 
23*799 grains gave, by ignition with oxide of copper, 7'085 of water, indicating 3‘31 
per cent, of hydrogen. 
14*663 grains gave 6’2247 cubic inches of pure nitrogen reduced to 30 inches 
barometer and 32° Fahr., indicating 13’50 per cent, in weight. 
The formula to which this analysis leads is remarkable ; it is Pt 2 Cl N 3 H 10 0 4 , 
which gives the following numerical 
results : — 
Two equivalents of platinum 
. 197-6 
62-28 
61-80 
One equivalent of chlorine . 
35-4 
11-16 
11-35 
Three equivalents of nitrogen 
42-3 
13-33 
13*50 
Ten equivalents of hydrogen 
io-o 
3*15 
3-31 
Four equivalents of oxygen . 
32-0 
10-08 
10-04 
317-3 
100-00 
100-00 
