DR. A. W. HOFMANN ON THE PHOSPHORUS-BASES. 
465 
pui’ified. If the chloride thus formed be precipitated with excess of nitrate of silver, 
and the nitrate of the base, filtered from the chloride of silver, be mixed with ammonia 
and gently heated, a copious precipitate is immediately formed, consisting of bromide of 
silver. This reaction is characteristic of the bromethylated body. Moreover, on mixing 
the solution of the nitrate freed from silver with dichloride of platinum, and recrystal- 
lizing the platinum-precipitate from boiling water, the liquid yields on cooling the 
splendid needles of the platinum-salt of the bromethylated triethylphosphonium. The 
analysis of this salt was omitted, partly because no doubt could be entertained respect- 
ing its nature, and partly because I had occasion to establish by a number — as will be 
noticed hereafter — the nature of the precisely similar reaction between chloride of 
oxethyl-triethylphosphonium and pentachloride of phosphorus. 
Thus it is seen that the molecular group C2 Hg O, which is supposed to replace the 
hydrogen in the salt, sufiers, under the influence of pentabromide of phosphorus, altera- 
tions exactly similar to those which it would have undergone under similar circum- 
stances when conceived as a constituent of alcohol. 
If w’e consider the facility with which the bromethylated phosphonium is converted 
into the oxethylated compound by the action of oxide of silver, and the simple re-for- 
mation of the first-mentioned body by means of pentabromide of phosphorus, a great 
variety of new experiments suggest themselves. In reviewing the relations which obtain 
between the bromethylated and oxethylated phosphoniums, who could fail to perceive 
that the two hydrogen -replacing radicals, which constitute the difference between these 
two organic metals, stand to one another in the same relation as bromide of ethyl and 
alcohol, or bromide of acetyl and acetic acidl But if this be so, what a number of 
new bodies does this consideration bring into view, even if we limit our calculation to 
the transformations of which the molecular group C2 Hg O in alcohol is susceptible ! 
As yet I have scarcely penetrated into this new field of inquiry, and I must be satisfied 
to quote a single experiment, which exhibits the above-mentioned bodies in a new light. 
The salts of bromethylated and oxethylated triethylphosphonium may be regarded as 
tetrethylphosphonium salts, in which an atom of hydrogen is replaced by bromine and 
the radical H O respectively : 
Bromide of tetrethylphosphonium [(C2 H4 H) (Cg H5)3 P] Br, 
Bromide of bromethylated triethylphosphonium . [(C2 PI4 Br)(C2 Hgjg PJ Br, 
Bromide of oxethylated triethylphosphonium . . [(C2 H4 H 0)(C2 Hg)3 P] Br ; 
and the question arose whether the bromethylated salt might not be converted by 
a simple process into the tetrethylphosphonium-compound. This transformation may 
indeed be effected without the slightest difficulty. On acidulating the solution of the 
bromethylated bromide with sulphuric acid, and digesting it with granulated zinc, 
the bromine is eliminated in the form of hydrobromic acid, its place being filled up by 
one equivalent of hydrogen : 
1 (C, H, Br) (C^ HJ, P] Br + H2=HBr + [(C, H,,)^ P] Br. 
3 Q 
MDCCCLX. 
