582 
EESEAECHES OP DE. HOF^klAXNT AXD M. CAHOTES 
facility with which it decomposes at 100° C., must be dried in the exsiccator. Lu the 
water-bath it fuses and is altogether decomposed. The determination of the plati- 
num in the phosphorus-compounds presents considerable difficulties. The platinum in 
these substances cannot be determined in the ordinary way by simple ignition, because 
a considerable quantity of platinum is carried otf with the phosphorus-rapour, however 
slowly and carefully the process may be carried out. iVe unfortunately did not find 
this out, until a great number of unsuccessful analyses had been made. By heating 
with a considerable excess of carbonate of sodium in a porcelain crucible on a sand- 
bath, the temperature of which is gradually raised, the determination succeeds with- 
out difficulty. After removal of the portion soluble in water, the platinum-residue, 
which is always contaminated with silicic acid, is dissolved in nitrohydrochloiic acid, 
the solution evaporated to dryness, and the residue again dissolved in acid : the careful 
evaporation of this solution furnishes a perfectly accurate result. This method is some- 
what tedious, but there is some compensation for this increased complexity by the 
simultaneous determination of the chlorine. 
The analysis of the platinum-salt of triethylphosphine has furnished the following 
results : — 
0'2795grm. of platinum-salt gave 0'3725grm. of cliloride of silver and 0-0855 grm. 
of platinum, corresponding to the formula 
HCl, PtCl,=E3P, HCl, PtCl^. 
Theory. Experiment. 
12 equivs. of Carbon 
. 72 
22-2i 
16 equivs. of Hydrogen 
. 16 
4-94 
1 equiv. of Phosphorus . 
. 31 
9-56 
3 equivs. of Chlorine . 
. 106-5 
32-85 
32-96 
1 equiv. of Platinum . 
. 98-7 
30-44 
30-59 
1 equiv. of Platinum-salt 
. . 324-2 
100-00 
The preceding experiments sufficiently fix the composition of triethylphosphine. This 
compound is in fact triethylamine, in which the nitrogen is replaced by an equivalent 
quantity of phosphorus. The perfect analogy -with triethylamine is also shown by the 
deportment of the phosphorus-base with the iodides of ethyl, methyl and amyl. Tri- 
ethylphosphine combines with these substances, forming well-crystallized and highly 
characteristic salts, which may be regarded as iodide of ammonium, in which the nitrogen 
is replaced by phosphorus and the hydrogen by the radicals of the alcohols. 
Iodide of Tetrethylphosplionium. 
On mixing triethylphosphine with iodide of ethyl, a riolent action ensues after a few 
moments ; the liquid effervesces with almost explosive Aiolence, and then solidifies to a 
white crystalline mass. If, instead of the pure base, an ethereal solution be employed, 
the crystals are formed more slowly. This new compound is extremely soluble in 
