438 
DE. A. W. HOFMANX OX THE PHOSPHOEU-S-BASES. 
in the urea. The same instability is perceptible in the general deportment of the com- 
pound. Even extremely dilute nitric acid liberates the sulphocyanate of phenyl, whilst 
the phosphorus-base is converted into the oxide. The chloiade is one of the more stable 
salts of the urea, but it is likewise readily altered ; on addition of a large quantity of 
water, the solution of the salt becomes milky, the sulphocyanate of phenyl being sepa- 
rated in oily globules, and now contains the chloride of tiiethylphosphonium. On 
adding ammonia to the concentrated solution of the chloride, the urea, as has been already 
stated, is separated without change, and may be readily recovered by taking up with 
ether and crystallizing. If, on the other hand, the dilute solution be boiled with 
ammonia, the turbidity perceptible in the commencement disappears again, and after a 
few moments beautiful crystals of plienyl-suljrjhocarbamide ai’e deposited, trieihyl- 
phosphine being simultaneously liberated : 
(C S)" ] (C S)" 1 
(C2 11,), N P+H3 N = (G, ll,), P+(Ce H3) X,. 
(CeHg)] H 3 J 
On treating the chloride with potassa, phenomena exactly analogous are obseiwed ; 
the crystals which are separated, are, however, diphenyl-siilphocarhamide : 
r(C S)" 
(C2H3)3^NP +4 
.(Cg H5) 
K 
K 
K 
= S + CO3 + 
K 
H 
H 
(CS)" 1 
O + 2[(aH3)3P]+(CeH0,;>X.3. 
H., 
If a few drops of disulphide of carbon be added to the solution of the urea, the liquid, 
when gently heated, assumes a deep red colour, and deposits on cooling the beautiful 
ruby-red crystals (C2 115)3 C! S2, which I have mentioned in a pre^ious paragraph of 
this paper. The mother-liquor of these crystals furnishes on evaporation oily di’oplets 
of sulphocyanate of phenyl. The urea, even when perfectly pure and di’y, cannot be 
preserved without undergoing a gradual alteration. If the crystals be left under a 
bell-jar containing atmospheric air, they become dull, and at last moist and sticky, whilst 
a peculiar extremely disagreeable odour, distantly resembling that of hydrocyanic acid, 
becomes perceptible ; at the same time, a delicate net-work of tine needles begms to 
appear on the glass, easily recognized as sulphide of triethylphosphine. The crystals 
of the urea fuse at 57°'5, forming a yellow liquid, which, in consequence of incipient 
decomposition, resolidifies but slowly and imperfectly. At 100^ the phenomena just 
mentioned are much more distinctly observed, and especially the smelling body is 
unmistakeably perceived. The peculiar-smelling body is likewise almost overwhelm- 
ingly produced on evaporating the ethereal mother-liquor of the compound. As yet I 
have not been able to lay hold of the possessor of this remarkable odour. The ethereal 
mother-liquor, when evaporated, leaves a brown syrup, which after some time deposits 
large crystals of sulphide of triethylphosphine. Submitted to distillation, this residue 
yields, together with other products, an additional quantity of the crystallized sulphur- 
compound. 
