310 



so, as to render it necessary to cool the apparatus in water, and add 

 the well-dried salt by degrees. An excess of the latter must be 

 avoided, since chloride of mercurous ethyl would be formed, as was 

 formerly shown to be the case in the methyl series. 



After the two bodies have been brought together in their proper 

 proportions, heat is applied, and the radical passes over by distillation 

 as a heavy, colourless, and nearly inodorous liquid ; the slight excess 

 of zinc-ethyl is then decomposed by the addition of water, and just 

 sufficient dilute hydrochloric acid added as will dissolve the preci- 

 pitated oxide of zinc. 



The two transformations may be seen in the equations, 



C 4 H 5 Zn + Hg C1=C 4 H 5 Hg+Zii Cl, 

 and again, 



C 4 H s Hg + HgCl=C 4 H 5 Hg 2 Cl. 



The pure radical boils at a temperature between 158 and 160 G. 

 It burns readily, with a luminous and somewhat smoky flame, with 

 disengagement of mercurial vapour. It is almost wholly insoluble 

 in water. Alcohol dissolves it rather sparingly, but it mixes freely 

 with ether. 



The behaviour of acids towards mercuric ethyl is strictly analogous 

 to that shown by mercuric methyl. With dilute acid there is but 

 little change, but warm concentrated hydrochloric or sulphuric acid 

 liberates hydride of ethyl in sufficient quantity to permit of its 

 inflammation through a gas jet. The salts of mercurous ethyl 

 remain in solution. 



The specific gravity of a specimen boiling between 158 and 160 C. 

 was found to be 2'444, and the same sample when submitted to 

 analysis, gave numbers agreeing accurately with the formula 



C 4 H 5 Hg. 



The correctness of this formula was further confirmed by an appeal 

 to the vapour-density. 



The first experiment failed, from the circumstance that the vapour 

 decomposes with a slight explosion, when heated a few degrees 

 above 205 C. In this experiment metallic mercury was deposited 

 on the walls of the glass balloon as a grey film, and the other 

 contents consisted of an inflammable gas. Mercuric methyl appears 

 therefore to be resolved at this temperature into ethyl gas and* 

 mercury. 



