302 
DR. KANE ON THE CHEMICAL HISTORY 
the present I shall only put it forward in a purely empirical form, as follows : 
Pt 2 Cl 5 H n N 2 0 4 , which gives the following numbers : — 
Two atoms of platinum = 
197*6 
44*35 
Five atoms of chlorine = 
177*0 
39*72 
Two atoms of nitrogen = 
28*2 
6*28 
Eleven atoms of hydrogen = 
11*0 
2*47 
Four atoms of oxygen = 
32*0 
7*18 
445*8 
100*00 
III. The substance used in analysis No. 1. was again boiled for a short time in 
water of ammonia, but without allowing the colour to become perceptibly altered, it 
was then dried at a temperature of 120°, and analysed. 
14*462 grains of substance gave, by the usual treatment, 6*467 of metallic platinum, 
equivalent to 44*72 per cent., and 23*799 of chloride of silver, equivalent to 40*61 of 
chlorine. 
24*139 grains of substance burned with oxide of copper gave 4*799 of water, or 
2*21 of hydrogen per cent. 27*968 gave, by the usual method, 5*602 cubic inches of 
pure dry nitrogen, weighing at standard temperature and pressures 1*7961 grain, and 
hence equivalent to 6*44 per cent. 
The experimental results are hence as follows : — 
I. 
II. 
III. 
Platinum 
. 44*24 
44*47 
44*72 
Chlorine 
. 41.94 
41-20 
40*61 
Nitrogen 
7*09 
6*44 
Hydrogen 
2*17 
2*30 
2*21 
Oxygen . 
4*56 
6*92 
100*00 
100*00 
It is very remarkable that in all these results the chlorine appears to be a little 
(about 1 per cent.) above the theoretical number ; this is perhaps due to the pre- 
sence of traces of the double chloride of platinum and ammonium, which, from its 
sparing solubility, if once formed is very difficult to be removed, and is not changed, 
except when the accompanying bodies are also decomposed. The composition of 
this substance is, however, evidently the same, although prepared under varied cir- 
cumstances ; and it may also be produced, even in the cold, by allowing chloride of 
platinum to remain in contact with an excess of water of ammonia for a considerable 
time. 
When this substance is heated to about 250° or 300° it abandons some water, but 
no ammonia. The quantity of water thus given off, was found to be 2*57 per cent. 
By the loss of one equivalent it should be 2 per cent., and hence probably the per- 
fectly dried substance has the composition of Pt 2 Cl 5 N 2 H 10 0 3 . 
The formula of this body presents a remarkable relation, which may be at the pre- 
