344 



Po tassium- ethy I. 



Zinc-ethyl and potassium react still more readily than the former 

 body and sodium. So far as at present ascertained, the cases greatly 

 resemble one another. Just as with sodium, I obtain crystals readily 

 soluble in zinc-ethyl, which contain in this case abundance of 

 potassium. 



Seeing that the kind of reaction brought under notice in this 

 paper is apparently unique, it is necessary to offer a few observations 

 upon it. 



9 Zn \ Na) _ 9 Na \ Zn 



C 4 Hj+Na/ = "C 4 H 5 j+Zn 



The reaction here formulated may be regarded as an electrolytic 

 decomposition as an ordinary case of precipitation of one metal by 

 a more electro-positive metal. Here ethyl is the electro-negative, 

 and zinc the electro-positive member : sodium is more electro-posi- 

 tive than zinc, and accordingly sodium displaces zinc. 



Following out the hypothesis where the organo-metallic body 

 contains a metal less electro-positive than the hydrocarbon radical, 

 I should expect that the hydrocarbon radical would be eliminated 

 by the action of sodium. Kakodyl, for instance, should give methyl 

 and arsenide of sodium. 



C 2 H 3 1 A Nal _Na| A C 2 H 3 

 t$CT + Na}-Na| j ' +C 2 H 3 



A case in point is afforded by the reaction of the alkali-metals 

 with ammonia. 



HI -rr > K] TT> 



2. HlN+ =2.HlN+ii[ 

 Hj K J HJ 



Of the same kind is the reaction of zinc-ethyl upon ammonia*. 

 HI 7 Zn 1 



H [ N +rn I =H [ N + r 



HJ C A;J HJ C * 



To develope the hypothesis still further : just as the positive side 

 admits of displacement by a more electro-positive radical, so should 

 the negative side admit of displacement by a more electro-negative 

 body. 



* See Frankland's paper, Trans. Royal Soc. 1857. 



