386 Royal Society : — 



I have already mentioned, in a previous note, the deportment of 

 the hromethylated bromide with oxide of silver ; the whole of the 

 bromine is eliminated in the form of bromide of silver, a new base 

 being formed. 



According to circumstances, this base may be the vinyl-compound 

 previously mentioned, or another body differing from the latter by 

 containing the elements of one molecule of water in addition. This 

 substance, which is always formed when the reaction takes place in 

 moderately dilute solutions, is the oxide of a phosphonium, with three 

 molecules of ethyl substituted for three equivalents of hydrogen, the 

 fourth equivalent of hydrogen being replaced by an oxygenated radical 

 C 2 H 5 O, arising from the radical C 2 H 4 Br by the insertion of HO in 

 the place of Br 



[(C 2 H 4 Br) (C 3 H 5 ) 3 P] Br + 2^ 1 o = 2 AgBr + ^ C ^ H ^ H0 ) ( C 2 H 5 ) 3 P] j a 



I have fixed the nature of this compound by the analysis of the 

 iodide, of the platinum-salt and of the gold-salt, and, moreover, by 

 the study of several remarkable transformations which it undergoes 

 when submitted to the action of reagents. 



It appeared of some interest to ascertain whether the oxethylated 

 might be reconverted into the hromethylated base. The chloride of 

 the former is energetically attacked by pentabromide of phosphorus ; 

 oxybromide of phosphorus and hydrobromic acid are abundantly 

 evolved, and the residue of the reaction contains the chloride of 

 hromethylated triethylphosphonium. 



[(C, H s 0) (C 2 H 6 ) 3 P]Cl + PBr 5 =HBr + POBr 3 + [(C 2 H 4 Br) (C 2 H 5 ) 3 P]0. 



Thus it is seen that the molecular group C 2 H 5 O, which we assume 

 as hydrogen- replacing in this salt, suifers under the influence of 

 pentabromide of phosphorus, alterations identical with those which 

 it is known to undergo under similar circumstances, when conceived 

 as a constituent of alcohol. 



If we consider the facility with which the hromethylated triethyl- 

 phosphonium is converted into the oxethylated compound, by the 

 action of oxide of silver, and the simple re-formation of the first- 

 mentioned body by means of pentabromide of phosphorus, a great 

 variety of new experiments suggest themselves. As yet but little 



vapour of triethylphosphine, the residuary solution retaining hydrated oxide of 

 vinyl-triethylphosphoniurn , 



[(C 2 HJ"(C 2 H 5 ) 6 FJT | q 2 = (Ca Hfi)a p+ h 2 0+ C(C a H 3 ) (C 2 H 3 ) 3 P] j Q> 



the latter yielding at a higher temperature the oxide of triethylphosphine together 

 with ethylene, 



C(C a H 3 ) (C 2 H 5 ) 3 P] 1 = c 2 H 4 +(C 2 H 3 ) 3 PO. 



und is even more readily obtained by the actio 

 of silver, at the temperature of 100°, on th< 



[(C J H,B,)(C 2 H i ),P]Br +2 [^ H .«)}0]=2AsBr +[(CiHi)( 4 C fl » : °]}0+^H,0,| . 



The vinyl-compound is even more readily obtained by the action of silver-salts, 

 such as acetate of silver, at the temperature of 100°, on the hromethylated 

 bromide. 



