ON THE PHOSPHORUS-BASES. 
579 
and receiver may be cooled by water or ice, the action is nevertheless invariably so 
violent, that all the ether, and with it a large quantity of the zinc-ethyl, passes over into 
the receiver. By the powerful ebullition which periodically ensues, a portion of the 
vapour is driven even into the bent tube, and a considerable loss of zinc-ethyl is incurred 
unless this tube be filled with terchloride of phosphorus, which greedily absorbs every 
trace of the former compound. This fiuid valve, ascending and descending in the tube, 
in accordance with the progress of the reaction, regulates the function of the apparatus 
so perfectly, that the operation, which always takes several hours, when once begun con- 
tinues by itself. Sometimes the absorption is so violent that the terchloride of phos- 
phorus in the tube is sucked back into the receiver, but even then no loss is to be feared, 
since the tube is connected with the reservoir filled "with carbonic acid. 
The first drops of terchloride of phosphorus which fall into the solution of zinc-ethyl, 
hiss like water when coming in contact with red-hot iron. The action becomes by-and- 
by less violent, and as soon as an evolution of heat is no longer perceptible, the opera- 
tion is terminated. There remain in the retort, in the receiver, in the bent tube, and 
sometimes even in the carbonic acid reservoir, two liquid layers, — the one a heavy pale 
straw-coloured thick fluid, the other a transparent colourless mobile fluid floating on 
the former. 
The hea\y fluid, a compound of the phosphorus-base with chloride of zinc, nearly solidi- 
fies on coohng, but the viscid transparent mass exhibits no trace of crystalline structure. 
The light fluid is a mixture of ether with an excess of the terchloride of phosphorus ; 
after disconnecting the apparatus, it is poured off from the viscous fluid, and may be used, 
after distillation, in a second operation. 
In order to liberate the phosphorus-base fi-om its combination with zinc, nothing more 
than a distillation with potassa is required. To prevent the destruction of the retort, to 
which the zinc-compound adheres with pertinacity, and the loss of so precious a material, 
this operation is conveniently performed in the following manner. Solid hydrate of 
potassa is placed on the hard resinous cake attached to the bottom of the retort, and a 
slow current of water allowed to flow in by the dropping apparatus, after the air in the 
retort has been carefully displaced by hydrogen : the heat evolved during the reaction 
is quite sutficient to volatilize the base with the vapour of the water ; it may be con- 
densed by an ordinary cooler. The base, which is now floating on the water of the distil- 
late, is removed by means of a separating funnel ; it is allowed to stand for a day over 
hydrate of potassa, and finally rectified in a current of dry hydrogen gas. 
Triethylphospliine. 
Thus obtained, triethylphosphine is a colourless, transparent, mobile liquid, which 
strongly refracts light. The compound is lighter than water, its specific gravity being 
found to be 0-812 at 15°-5 C. ; it is perfectly insoluble in water, but soluble in every pro- 
portion in alcohol and ether. Its odour is penetrating, almost benumbing, but still not 
disagreeable. The intolerable smell which renders it so unpleasant to work with these 
