346 



since repeated this experiment with the addition of ether, and has 

 obtained the same result as regards the non-formation of an organo- 

 metallic compound. 



The temperature at which sodium decomposes iodide of ethyl is 

 much lower than that at which sodium-ethyl is broken up, conse- 

 quently no explanation of the phenomenon can be obtained from 

 this source. In his observations on the formation of ethyl*, Brodie 

 mentions that iodide of ethyl is decomposed at 1 70 C. by zinc-ethyl; 

 and it therefore occurred to me that sodium-ethyl, owing to its more 

 powerful affinities, might effect the decomposition of iodide of ethyl 

 at a lower temperature than that at which iodide of ethyl is decom- 

 posed by sodium ; in which case the production of sodium-ethyl, by 

 the action of sodium upon iodide of ethyl, would be an impossibility. 

 Experiment completely confirmed this anticipation. A quantity of 

 a strong solution of sodium-ethyl in zinc-ethyl was thrown up into a 

 dry receiver filled with mercury, and an equal volume of pure iodide 

 of ethyl added to it. Immediately on the mixture of the two liquids, 

 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 was complete in two or three 

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

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

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

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

 fore be thus expressed : 



+C 4 H 4 . 



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

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

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

 latter could be effected at ordinary temperatures, since each particle 

 of the organo-metallic compound being in contact with iodide of ethyl 

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

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

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

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

 this formation and immediate decomposition of sodium-ethyl actually 

 * Journal of the Chemical Society, vol. iii. p. 405. 



