DE. A. W. HOFMANN ON THE PHOSPHOEUS-BASES, 
501 
crystallizing in scales from boiling water. I have contented myself with determining 
the amount of platinum in this salt. 
0-4794 grm. of platinum-salt, precipitated with sulphuretted hydrogen, &c., gave 
0-1502 grm. of platinum. 
Theory, 
Experiment. 
I equiv. of Diphosphonium 
222-0 
35-10 
2 equivs. of Platinum . 
197-4 
31-22 
31-33 
6 equivs. of Chlorine 
213-0 
33-68 
— 
I equiv. of Platinum-salt . 
632-4 
100-00 
The salts of the hybrid diphosphonium crystallize like those of the corresponding 
hexethylated compound, but, as far as they have been examined, are somewhat more 
soluble ; this remark applies especially to the di-iodide. 
It seemed worth while to try whether the bromide of bromethylated triethylphos- 
phonium was capable of fixing a molecule of phosphoretted hydrogen. I found, how- 
ever, that the two bodies do not act upon one another. Phosphoretted hydrogen gas, 
passed through the alcoholic solution of the bromide, either cold or boiling, did not 
seem to afiect it in any way. 
Action of Dibkomide of Ethylene on Teimethtlphosphine. 
This reaction exhibits a repetition of all the phenomena observed in that which takes 
place between the dibromide and triethylphosphine. The process is completed, if possible, 
even sooner than in the ethyl-series. The lower boiling-point and overpowering odour 
of the trimethylphosphine, render it advisable to mix the materials with considerable 
quantities of alcohol or ether ; moreover, on account of the extreme oxidability of the 
phosphorus-compound, it is necessai-y to operate in vessels filled with carbonic acid and 
immediately sealed before the blowpipe. After digestion for a short time at 100°, the 
mixture of the two liquids solidifies to a hard, dazzling white, crystalline mass, contain- 
ing the two bromides, 
C, H,, P Br^ 
[(C., H4 Br) (C P] Br, and 
(CH3)3F 
(CH3)3PJ 
Br 
21 
one or the other predominating, according to the proportions in which the two bodies 
were allowed to act upon one another. 
It is not difficult to establish by numbers the formation of these two bodies. 
Bromide of Bromethyl-trimethylphosphonmm . — When a solution of trimethylphosphine 
in absolute alcohol, mixed with a very large excess of dibromide of ethylene, is exposed 
for some hours to a temperature of from 50° to 60°, the liquid on cooling deposits well- 
formed crystals. It is desirable not to pass this temperature ; at the boiling-point of 
water the mixture turns brown, in consequence of secondary reactions. One or two 
crystallizations from absolute alcohol render the crystals perfectly pure ; they exhibit in 
this state the chemical and physical characters of the corresponding ethylated body. 
