ON THE PHOSPHOEUS- BASES. 
589 
and also crystallizes from these liquids, but less beautifully. The solubility in bisulphide 
of carbon is almost unlimited ; from this solvent it crystallizes imperfectly. 
The fusing-point of the bisulphide of triethylphosphine is 94° C.; it resohdifies at 88°. 
WTien heated beyond 100° C. the bisulphide is volatilized, with diffusion of a white 
vapour of a disagreeable sulphur-odour, which is but slightly perceptible at the common 
temperature. When heated with a quantity of water insufficient for its solution, the 
sulphur-compound rises to the surface as a clear transparent oil, which is copiously 
volatilized with the vapour of water. 
The solution of the bisulphide is without action on vegetable colours. The com- 
pound nevertheless appears to possess faintly basic properties. It dissolves more readily 
in hydrochloric acid, especially when concentrated, than in water, and the solution fur- 
nishes with bichloride of platinum a yellow precipitate, which however rapidly cakes 
into a resinous mass, gmng indications of decomposition by the separation of bisulphide 
of platinum, so that it was not adapted for analysis. The sulphur-compound also dis- 
solves in dilute sulplimic and nitric acids ; concentrated nitric acid decomposes it ; the 
fuming acid gives rise to a sort of detonation. The aqueous solution of the bisulphide 
is not affected by acetate of lead, nitrate of silver, or protoxide of mercm’y, even at the 
boiling temperature ; the alcoholic solution, on the other hand, is instantaneously decom- 
posed with separation of the sulphide of lead, silver or mercury. The liquid filtered off 
from the precipitates now contains the oxide of triethylphosphine, either free or in the 
form of acetate or nitrate, and may be readily separated by the addition of an alkali to 
the solution. The action of potassium upon this compound instantaneously reproduces 
the phosphorus-base. 
The bisulphide of triethylphosphine has the composition 
C„H„PS,=E3PS,. 
I. 0T355 grm. of the substance, burnt in a glass tube with a mixture of common salt 
and chlorate of potassium, gave 0-2190 grm. of sulphate of barium. 
II. 0-4007 grm. of the substance yielded 0-623 grm. of sulphate of barium. 
Theory. Experiment. 
, A ^ , A ^ 
f ^ r ^ 
I. II. Mean. 
1 equiv. of Triethylphosphine .... 118 78-67 
2 equivs. of Sulphur 32 21-33 22-14 21-35 21-74 
1 equiv. of Bisulphide of triethylphosphine 150 100-00 
The formation of the bisulphide takes place with such facility, and the properties of 
the compound are so characteristic, that we have frequently used flowers of sulphur as a 
reagent for triethylphosphine. 
Biselenide of Triethylphosphine. 
In the action of selenium upon triethylphosphine, the phenomena described in the 
MDCCCLVII. 4 H 
