686 



group should, in correctness, be doubled. I have not, however, yet 

 been able to satisfy these views by direct experiment. Zincethyl 

 acts readily on salts of mercurous methyl ; and in all probability 

 gives a body compounded of ethyl and methyl with a double equi- 

 valent of mercury ^ C* H.\ ' ^ e su ^ stance however, if pro- 

 duced, is obviously broken by distillation into the two radicals mer- 

 curic ethyl and mercuric methyl. Experiment may perhaps prove 

 more successful if salts of stannic methyl be similarly treated. 



The electro-negative character of the group C D 2 H n2+1 in the class 

 of organo-metals to which zincethyl belongs, may now perhaps be 

 considered as established. Some interest, nevertheless, attaches to 

 the question whether sodium is capable of displacing ethyl from mer- 

 curic ethyl. An answer to this question would give us some means 

 of judging the position of ethyl, as regards its electro-negative func- 

 tion towards the true metals. 



At ordinary temperatures, sodium has only a slow action on mer- 

 curic ethyl, but after the lapse of a few hours a voluminous grey 

 sponge is formed, whilst the liquid entirely disappears. This sponge- 

 like body has the property of spontaneous combustibility in a marked 

 degree, and is liable to explosion from apparently very slight causes. 

 By the application of a gentle heat, a strong rush of gaseous matter 

 is evolved which eudiometric experiments proved to be a mixture 

 of ethylene and hydride of ethyl, obviously proceeding from the dis- 

 integration of a double molecule of ethyl. 



From this experiment we should conclude that ethyl, methyl, &c. 

 in these radicals are still negative to mercury, and therefore, that mer- 

 cury, copper, &c. would not, as Mr. Wanklyn supposes, displace 

 ethyl in sodiumethyl*. More probably, perhaps, sodiumethyl is 

 first formed in the reaction, and then decomposed by heat 



Hg C 4 H 5 + Na= Na C 4 H 5 + Hg 

 and by heat 



2 (Na C 4 H 5 ) + 2 Hg=2 Na Hg+ C 4 H 4 + C 4 H s H. 



The mercury is supposed here to be inert, and in no way to deter- 

 mine the decomposition. 



Stannic dietJiyl. 



Much of the uncertainty which has attached to some of the for- 



* Proc. Roy. Soc. vol. ix. p. 345. 



