DE. A. W. HOFMANN ON THE PHOSPHOEUS-BASES. 
445 
the diphosphonium-compounds in one of the following sections of this inquiry, I need 
not for the present enter into further particulars regarding this reaction. 
In concluding this paragraph, I may append a few remarks upon the deportment of 
sulphocyanate of triethylphosphonium under the influence of heat. This salt is readily 
procured by dissohing tiiethylphosphine in hydrosulphocyanic acid. Submitted to the 
action of heat, it is partly volatilized without decomposition ; the greater portion, how- 
ever, is decomposed, the sulphide and the disulphide-of-carbon-compound of triethylphos- 
phine, together with fi’ee disulphide of carbon, appearing among the volatile products 
of the reaction ; while a browm ill-defined substance remains in the retort, yielding, 
when treated with an alkali, an appreciable quantity of ammonia. I have not examined 
this change in detail, but it is obwoiis that one of the dhect products of the reaction is 
sulphocyanate of ammonium, the further decomposition of which explains the appear- 
ance of the disulphide of carbon, as well as the other products observed. The residue, 
of course, must contain the varied compounds generated by the action of heat on sulpho- 
cyanate of ammonium. 
Behaviour of the Arsines and Stihines with the Siilphocyanates of Phenyl and Allyl, 
The facility with which the compound ureas containing nitrogen and phosphorus are 
formed, induced me to attempt the production of analogous compounds with arsenic or 
antimony in place of phosphorus. I therefore treated sulphocyanate of phenyl and oil 
of mustard successively with triethylarsine and triethylstibine, first at ordinary and then 
at gradually increasing temperatures in sealed tubes. But not one of these experiments 
led to the expected result. The arsines and stibines differ, indeed, in their chemical 
characters much more from ammonia than the phosphines. Their incapability of forming 
saline compounds with acids is alone sufficient to render the formation of ureas contain- 
ing arsenic and antimony somewhat improbable. When mixtures of triethylarsine 
with sulphocyanate of phenyl on the one hand, and sulphocyanate of allyl on the other, 
were left to stand for some time at ordinary temperatures, the liquid in both cases was 
found to be traversed by a small quantity of beautiful needle-shaped crystals. The 
cr}"stals from both mixtures were found to be the same; they were readily identified 
with the white needles which are gradually formed in triethylarsine when left in con- 
tact with atmospheric air. 
Behaviour of Triethylj)hosphine with Cyanates. 
The formation of sulphuretted ureas containing phosphorus and nitrogen led me to 
try whether the corresponding oxygen-compounds could likewise be produced. 
When cyanate of jihenyl is mixed with the phosphorus-base, great heat is evolved, 
indicating a marked chemical reaction. The mixture on cooling solidifies into a mass of 
shining crystals which are insoluble in water, nearly insoluble in ether, and dissolve 
with difficulty even in boiling alcohol. By recrystallization from the last-mentioned 
solvent, the new body is easily obtained pure. The further examination of the resulting 
