300 
DR. KANE ON THE CHEMICAL HISTORY 
It is interesting to find here the form assumed by the ammoniacal compounds of 
quicksilver, but still hydrated, and so rendered much more complex. It is curious 
also to recognise in the two hydrated states of this red platinum body, the analogues 
to the two formulae assigned to the mercurial white precipitate before its true consti- 
tution was known. Thus Pt 0 2 + N H 4 . 1 . corresponds to the formula Hg 0 2 
+ N H 4 . Cl given by Mitscherlich, and Pt I 2 -J- Pt 0 2 + 2 . N H 3 is equivalent to 
that suggested by Mr. Richard Phillips, Hg Cl 2 + Hg 0 2 + 2 . N H 3 . I do not be- 
lieve, however, that the perfectly anhydrous condition of white precipitate can be 
given to this platinum body. 
On the Action of Ammonia on the Perchloride of Platinum. 
A. When a dilute solution of perchloride of platinum is added to water of ammonia, 
also dilute, a pale yellowish precipitate is produced, insoluble in cold water, but de- 
composed by boiling water, or even by much washing ; the double chloride of plati- 
num and ammonia being dissolved out, and the colour of the residue becoming much 
less yellow. 
When this powder is heated it gives out sal-ammoniac, chlorine, nitrogen, and 
leaves metallic platinum. No trace of water appears : it hence does not contain 
oxygen as a constituent. With muriatic acid it is changed into the common double 
chloride of platinum and ammonium. 
This substance was analysed as follows : — 
21*098 grains were carefully mixed with an excess of carbonate of soda, and ignited 
until the mixture was completely fused. The saline matter was then dissolved out 
with distilled water, and the metallic platinum remaining being collected and ignited, 
weighed 10*881 grains, =51*6 per cent. 
The solution having been acidulated by nitric acid was precipitated by nitrate of 
silver, the chloride of silver produced was collected and fused, it then weighed 18*521, 
equivalent to 38*8 of chlorine per cent. 
45*332 grains of another quantity, treated in a precisely similar way, gave 23*614 
of platinum, = 52*1 per cent., and 70*151 of chloride of silver, equivalent to 38*20 of 
chlorine per cent. 
These results indicate for the composition of this substance the very simple for- 
mula Pt Cl 2 -f N H 3 , which gives the numbers 
Theory. Experiment. 
One atom of platinum = 98*8 
52*38 
51*6 
52*10 
Two atoms of chlorine = 70*8 
37-94 
38*8 
38*20 
One atom of ammonia = 17'1 
9*68 
9.6 
9*70 
186*7 
100*00 
100*0 
100*00 
From the circumstance of no water being produced when this body is decomposed 
by heat, and the relation between the chlorine and platinum showing that these con- 
