OF PALLADIUM AND PLATINUM. 
295 
Ammonia-nitrates of Palladium. 
A. When a solution of nitrate of palladium is heated with a considerable excess 
of water of ammonia, or when ammoniacal gas is passed into the solution, a 
colourless liquor is ultimately obtained, the precipitate which first forms being per- 
fectly redissolved. By careful evaporation, this solution deposits a pure white salt 
in rhombic crystals (prisms or plates), of a brilliant pearly lustre. When heated, 
this salt fuses, and deflagrates violently with a brilliant white flame, depositing 
metallic palladium, and evolving water and nitrogen gas. The existence of this salt 
and its property of so exploding has been long known, and its composition only re- 
mained to be determined by me. 
I. 20*696 grains of this salt in good crystals were mixed with powdered glass, and 
placed in a tube : in front of the mixture was put oxide of copper, and in front of that 
again clean metallic copper, in thin turnings. The latter part of the tube having been 
heated to redness, heat was applied to the part of the tube containing the mixture, and 
the gas and watery vapour brought into contact with the oxide and metallic copper. 
The water was collected in a chloride of calcium tube, the last portions being obtained 
by breaking open the far extremity of the analysis tube which had been formed to a 
point for the purpose, and drawing by the mouth a current of air through the appa- 
ratus: the quantity of water was 8T80, or 39*53 per cent., containing 4*39 of hydrogen. 
II. 16*036 grains were mixed with powdered glass, and heated in a platinum cruci- 
ble, at first gently, until all volatile products had been expelled, but then to dull red- 
ness. The weight of the glass used being known, it was found that there remained of 
metallic palladium 5*725, or 35 71 per cent. 
III. 16*237 grains being mixed with powdered glass and placed in a tube with 
oxide of copper and metallic copper as in the last experiment, but from which a nar- 
row tube passed to a graduated jar in the water-pneumatic trough, the decomposi- 
tion was effected, and the volume of the nitrogen gas evolved determined as already 
noticed in the analysis of the basic nitrate. It measured 14*7075 cubic inches, 
weighing 4*7149 grains, equivalent to 29*04 per cent. 
The composition of this salt is, therefore, 
Palladium . . . 
. . 35*71 
Nitrogen .... 
. . 29*04 
Hydrogen . . . 
. . 4*39 
Oxygen (by loss) . 
. . 30*86 
The formula N 0 5 + Pd O -}- 2 .N H 3 , exactly agrees with these results, giving 
Pd = 53*3 
35*70 
PdO = 61*3 
41*09 
N 3 = 42*0 
28*13 
N 0 5 = 54*0 
36*12 
0 6 = 48*0 
32*15 
2 . N H 3 = 34*0 
22*79 
o 
(o 
II 
X 
4*02 
1 49*3 
100*00 
149*3 
100*00 
