290 



to the same series, the elements of hydrobromic acid having separated 

 from the original compound metal. 



C 4 En 

 Br + 2AgO=2AgBr+^** 5 I PO, HO. 



CXJ 



The compound thus obtained may be designated as the hydrated 

 oxide of triethyl-vinyl-phosphonium. 



I have ascertained by experiment that the brominetted bromide is 

 by no means the only result of the action of bibromide of ethylene 

 on triethylphosphine, although under favourable circumstances it 

 appears to be the chief product. Invariably a portion of the bibro- 

 mide, faithful to its traditions, splits into hydrobromic acid and 

 bromide of vinyl ; and we find therefore in the white crystalline mass 

 always, together with hydrobromate of triethylphosphine, a certain 

 quantity of the very bromide of triethyl-vinyl-phosphonium, which, 

 as has been stated, results from the action of oxide of silver on the 

 brominetted bromide. 



t jj i 

 C 4 H| I P 



+C 4 H 4 Br 2 = 



The action of bibromide of ethylene on triethylphosphine, complex 

 as it is, receives an additional element of complication by the influ- 

 ence of heat. Ebullition appears to facilitate the formation of a 

 fourth bromide, which, although less prominently, is also produced 

 in the cold. The study of this compound is not yet completed. 



VII. " Researches on the Phosphorus-Bases." No, II. Action 

 of Bisulphide of Carbon on Triethylphosphine. By A. W. 

 HOFMANN, Ph.D., F.R.S. &c. Received June 5, 1858. 



Among the many characteristic reactions of the phosphorus-bases, 

 their deportment with sulphur is so conspicuous that it has served 

 frequently as a test for the presence of these substances. In con- 

 tinuing the study of the phosphorus-bases, I have found that this 

 remarkable attraction for sulphur is by no means limited to this 

 element in the free state. Many sulphur-compounds, when coming 



