442 
DE. A. W. HOFilAXN’ OX THE PHOSPHOEUS-BASES. 
faces 10 0 and through the faces 2 01 ; another system is seen through the faces 0 01 . 
The apparent angle of the optical axes is about 38°, if the first sj'stem of rings be 
observed through 10 0, and about 68 ^° if this system be seen through 2 01. The mean 
index of refraction, i. e. of that which corresponds to a ray l)ing in a plane parallel to 
010 and polarized in that plane, is /3=1’657. Hence it follows that the internal angle 
of the optical axes is about 72^°. 
Hardness less than that of gypsum,” 
Platinum-salt . — I have contented myself with verr^'ing the foi-mula of the aUyl-urea 
by the analysis of the platinum-salt. The allyl-compound dissolves readily in hydro- 
chloric acid, and the solution, when mixed with dichloride of platinum, yields a light- 
yellow scaly precipitate having a silky lustre, which fuses to a yellow oil in boiling water. 
0'6605 grm. of the crystals, dried over sulphuric acid, precipitated by sulphui'etted 
hydrogen, &c., gave 0T282 grm. of platinum. 
The formula 
requires 
CioH2iNPSPtCl3 = 
■ (C S)" 
L. (C2H5)(C3 
H= 
Cl, Pt Cl, 
Theory. 

Experiment. 
1 equiv. 
of Allyl-compound . 
. 217 
51-28 
1 equiv. 
of Hydrogen . . 
1 
0-23 
1 equiv. 
of Platinum . . . 
. 98-7 
23-32 
22-87 
3 equivs. 
of Chlorine 
. 106-6 
25-17 
1 equiv. 
of Platinum-salt . . 
. 423-2 
100-00 
The allyl-base described in the preceding pages has the composition of sulphocyanate 
of triethyl-allylphosphonium : 
(CS)" 'I 
NP 
(C2H3)(C3H3)J 
1 felt some interest in comparing the latter compound with the allyl-base. Iodide of 
aUyl acts with the greatest energy upon triethylphosphine. The solid product of the 
reaction, recrystallized from alcohol, furnishes splendid needles of iodide of triethyl- 
all ylpho sphonium . 
0‘6740 grm. of iodide, dried in vacuo, gave 0’5535 grm. of iodide of silver = 44’38 per 
cent, of iodine. 
The formula [(C, H 5)3 (C 3 H,) P] I 
requires 44-40 per cent, of iodine. 
Treatment with chloride and oxide of silver yields the corresponding chloride and 
hydrate. They resemble in every respect the tetrethylphosphonium-compounds. The 
CN 
[(C2H3)3(C3H3)P 
s. 
