OF PALLADIUM AND PLATINUM. 
287 
examined this trace of brown matter, and found its composition variable, and that it 
contains oxygen, as it evolves water when heated. It is most probable that the am- 
monia-chloride is partially decomposed by water into the olive body (B.) and sal- 
ammoniac, thus 4 (Pd . Cl . N H 3 ) and 2 . H O give Pd 4 Cl 0 2 N H 2 and 3 . N H 4 Cl, 
and that this olive substance (hydrated) combines with a certain quantity of ammo- 
nia-chloride, undecomposed, or is more probably but mixed with it. The formula 
Pd 9 CI 3 N 3 H 15 0 12 = Pd . Cl . N H 3 + 2 (Pd 4 Cl N H 6 0 6 ) gives very accurately the re- 
sult obtained by Fehling. 
It may be remarked, however, that another and very interesting formula expresses 
the composition of Fehling’s substance. It is this : Pd 3 Cl N 2 H fi 0 2 , or rationally, 
Pd Cl + 2 . Pd N H 2 + 2 Aq. This gives 
Theory. 
Fehling. 
Pd 3 . . 
. 159*9 
65*18 
64*18 
Cl . . 
. 35*4 
14*43 
14*85 
2 NH 3 . 
34*0 ] 
16*0 J 
20*39 
20*97 
o 2 . . 
245*3 
100*00 
100*00 
It should then be an oxychloride of palladium united to ammonia, or a hydrated 
chloramidide of palladium, analogous in constitution to the very peculiar oxychloride 
of copper, Cu Cl + 2 Cu O, which I have elsewhere described. 
The observations I have had occasion to make respecting the iodides and cyanide 
of palladium, and the bodies derivable from them, agree perfectly with those obtained 
by Fehling, and published in the memoir to which I have so often had occasion to 
refer, on the relation of the haloid compounds of palladium to ammonia, inserted in 
Liebig’s f Annalen der Chemie und Pharmacie.’ I deem it hence unnecessary to notice 
any of those results in detail, as they already have been placed before the public. 
Of the Sulphates of Palladium. 
The sulphate of palladium is best prepared by dissolving the metal in a mixture of 
sulphuric acid and nitric acid, the former being in excess, and evaporating the deep 
brown red liquor so obtained to the consistence of a syrup. On cooling, it crystal- 
lizes, though very confusedly, and only when so concentrated as to become almost 
completely solid. 
In this state it tastes sour and metallic. It is reddish brown coloured, very solu- 
ble in water, and in damp air deliquescent. It contains water of crystallization. Its 
composition was determined as follows : — 
45*286 grains of the crystalline mass, dried between folds of bibulous paper, were 
heated cautiously as long as any traces of moisture were given olf. The residual 
mass weighed 38*124 grains, or 84*19 per cent., having lost 15*81 per cent, of water. 
