890 'Royal Society :— 



a lively effervescence set in, a considerable quantity of gas collected 

 in the receiver, and a white deposit of iodide of sodium rendered the 

 liquid thick and turbid. The reaction VFas conaplete in two or three 

 minutes without the application of heat. An analysis of the gas, 

 previously freed from the vapours of iodide of ethyle and zinc-ethyle, 

 showed it to consist of equal volumes of hydride of ethyle and olefiant 

 gas, mixed only with a mere trace of ethyle. This reaction may there- 

 fore be thus expressed : — 



C, H, Na + C, H, I=NaI + ^^ g' } + C, H,. 



It is therefore evident that sodium-ethyle, and the remark no doubt 

 applies also to potassium-ethyle, could not be obtained by the action 

 of sodium upon iodide of ethyle, even if the decomposition of the 

 latter could be effected at ordinary temperatures, since each particle 

 of the orgauo-metallic compound being in contact with iodide of ethyle 

 at the moment of its formation, would be instantly decomposed in 

 the manner just described. That olefiant gas and hydride of ethyle, 

 with mere traces only of ethyle, constitute the gaseous product of the 

 decomposition of iodide of ethyle by sodium, is strong evidence that 

 this formation and immediate decomposition of sodium-ethyle actually 

 takes place. Sodium-ethyle tluis stands in the same relation to iodide 

 of ethyle as hydride of zinc does to hydriodic acid ; and consequently 

 all attempts to produce hydride of zinc by the action of the metal 

 upon the hydrogen acids have failed. These considerations, taken 

 in connexion with Mr. Wanklyn's mode of forming sodium-ethyle and 

 potassium-ethyle, afford a clue to the nature of the reactions by which 

 we shall probably eventually succeed in forming the hydrogen com- 

 pounds of the highly positive metals, xllthough the hydrogen com- 

 pounds of arsenic, antimony, phosphorus, and tellurium are by no 

 means exact analogues of zinc-ethyle, it would nevertheless be interest- 

 ing to ascertain the action of sodium upon these bodies, with a view 

 to the formation of hydride of sodium. 



The nature of the gas evolved by the action of sodium-ethyle upon 

 iodide of ethyle, has some interest in connexion with the formation of 

 ethyle by the action of zinc upon iodide of ethyle. Brodie expressed, 

 in the memoir above alluded to, an ingenious and highly probable 

 hypothesis, that the true source of the ethyle is the decomposition of 

 its iodide by zinc-ethyle, thus : — 



C, H, Zn-h C, H, I=ZnH-^* g= } ; 



and that the secondary products of the reaction (olefiant gas and hy- 

 dride of ethyle) which always accompany the ethyle, result from the 

 primary action of zinc upon iodide of ethyle, thus : — 



2(C, H, I) -f 2Zn = C , 11, + ^' g^ } + 2ZnL 



The composition of the gases produced in the above reaction of so- 

 dium-ethyle upon iodide of ethyle seems, however, to indicate that the 

 reverse of this hypothesis is true, and that the source of the ethyle is 



