DE. A. W. HOFMANN ON THE PHOSPHOEHS-BASES. 
429 
to sulphocarbamic acid, the ammonium salt of which, as is well known, is produced by 
the action of ammonia on disulphide of carbon. There is, however, no analogy in the 
constitution of the two substances. 
The new compound exhibits a remarkable tendency to pass into the sulphide of 
triethylphosphine. On mixing its alcoholic solution with oxide or nitrate of silver, car- 
bonic acid is evolved, sulphide of silver and metallic silver are separated, and the 
filtered solution, when evaporated, deposits crystals of the sulphide : 
(C, H,), P, C S2+2Ag2 0=Ag2 S+Ag2+C O^+CC^ HJ, P S. 
The disulphide-of-carb on-compound undergoes a similar change, even under the 
influence of moisture. Crystals, not dried with sufficient care, when kept in corked 
tubes, were changed after a few months into a yellowish white semifluid mass, of pecu- 
Har odour, which, by recrystallization from boiling water, furnished a considerable 
quantity of pure sulphide of triethylphosphine. To establish this transformation by 
numbers, the purified crystals were identified by analysis. 
I. 0-5345 grm. of the sulphide gave 0-9440 grm. of carbonic acid and 0-4915 grm. 
of water. 
II. 0-2460 grm. of the sulphide, oxidized with nitric acid, gave 0-3810 of sulphate of 
barium. 
The formula 
requh-es — 
Theory. 
Experiment. 
Ce 
72 
48-00 
r 
I. 
48-16 
II. 
15 
10-00 
10-21 
p 
31 
20-67 
S 
32 
21-33 
21-27 
150 
100-00 
It is obvious that the transformation of the red crystals into the sulphide involves 
the co-operation of the elements of water. Perfectly dry crystals were preserved in 
sealed tubes for many months without the slightest alteration. The crystals fuse at 95° 
and volatilize at 100°; in the absence of moisture, they may be heated underpressure to 
150° without undergoing any decomposition. The phenomena are very difierent in the 
presence of water. When exposed for some days in sealed tubes with water to a 
temperature of 100°, the red crystals are gradually transformed into white needles, which 
are easily recognized as sulphide of triethylphosphine. The transformation is inde- 
pendent of atmospheric air ; for it takes place with equal facility in vessels filled with 
air, or carbonic acid, or in vacuo. 
The products which accompany the sulphide formed in this reaction vary according 
to the time during which the red crystals are digested with water. If the tubes he 
allowed to cool after one or two days’ digestion, the liquid generally becomes filled with 
