DE. A. W. HOEMANN ON THE PHOSPHOEUS-BASES. 
413 
The difficulties which in our experiments opposed the preparation of this com- 
pound in the pure state, arose entirely from the comparatively small quantity of mate- 
rial with which we had to work. Nothing is easier than to obtain this oxide in a state 
of purity, provided the available quantity of material is sufficient for distillation. In 
the course of a number of preparations of triethylphosphine for the new experiments, 
a considerable quantity of the oxide had accumulated in the residues left after distil- 
ling the zinc-chloride-compound with potassa. On subjecting these residues to distil- 
lation in a copper retort, a large portion of the oxide passed over with the aqueous 
vapours, and a further quantity was obtained as a tolerably anhydrous but strongly 
coloured liquid, by dry distillation of the solid cake of salts which remained after all the 
water had passed over. The watery distillate, with or without addition of hydrochloric 
acid, was evaporated on the water-bath as far as practicable, and the concentrated solu- 
tion was mixed with solid hydrate of potassium, which immediately separated the oxide 
in the form of an oily layer floating on the surface of the potash. The united products 
*were then left in contact with solid potash for twenty-four hours, and again distilled. 
The first portion of the distillate still contained traces of water, a thin layer of 
triethylphosphine floating upon the surface. As soon as the distillate solidified, the 
receiver was changed, and the remaining portion (about nine-tenths) collected apart as 
the pure product. To prevent absorption of water, the quantity required for analysis 
was collected during the distillation. 
0*2589 grm. of oxide of triethylphosphine gave 0*5098 grm. of carbonic acid and 
0*2660 gi*m. of water. 
The formula 
requires the following values : — 
Theory. 
Experiment. 
Ce 
72 
53*73 
53*70 
Hi5 
15 
11*20 
11*41 
p 
31 
23*13 
0 
16 
11*94 
134 
100*00 
With reference to the properties of oxide of triethylphosphine, I may add the follow- 
ing statements to the description formerly given ^■. This substance crystallizes in 
beautiful delicate needles, which, if an appreciable quantity of the fused compound be 
allowed to cool slowly, frequently attain the length of several inches. I have been 
unable to obtain well-formed crystals ,* as yet I have not found a solvent from which this 
substance can be crystallized. It is soluble in all proportions, both in water and 
alcohol, and separates from these solvents on evaporation in the liquid condition, and 
solidifies only after every trace of water or alcohol is expelled. Addition of ether to the 
alcoholic solution precipitates this body likewise as a liquid. The melting point of oxide 
* Philosophical Transactions, 1857, p. 586. 
