1887 .] Prof. Letts and W. Wheeler on Benzyl Phosyliines. 75 
Owing to the small quantity of the primary phosphine at our 
command, it was not possible to obtain sufficient of the brominated 
body for further experiments. 
We also tried the action of alcoholic caustic potash and chloro- 
form on the phosphine, to see whether, under these conditions, a 
phosphorised nitrile could be obtained but with negative results, 
the phosphine remaining unacted upon. 
Our experiments with the primary phosphine are necessarily 
incomplete, owing to the very small quantity at our disposal, and 
the difficulty experienced in obtaining it in sufficient quantity. 
Bibenzyl Phosphine . — This body is readily purified from the 
crude product described on p. 68 by two or three recrystallisations 
from boiling alcohol. It crystallises from that liquid in colourless 
needles, which are quite unchanged by exposure to air. Dibenzyl 
phosphine is only sparingly soluble in cold alcohol, but it dissolves 
pretty readily in boiling alcohol. It is readily soluble in chloro- 
form, and is also soluble both in iodide of ethyl and in bisulphide of 
carbon. It is insoluble both in ether and in water. Glacial acetic 
acid is its best solvent. It melts at 205° (uncorrected), and sublimes 
at a higher temperature, with considerable decomposition. 
The following are the results of its analysis : — 
Carbon and Hydrogen — 
{: 
T795 gave 
1171 H20 = -013011 H= 7-2% 
5158 C02= -14067 C = 78-4% 
Phosphorus — 
-3645 gave -1963 Mg2P207= -05473 P= 15-0 % 
Calculated for 
Obtained. (C7H)72PH 
Carbon, .... 78-4 78-5 
Hydrogen, ... 7-2 7-0 
Phosphorus, . . .15-0 14-5 
Hofmann could not obtain any salts of dibenzyl phosphine, and 
considered it to be devoid of alkaline properties. We have found. 
