673 



Although there could be little doubt of the formation of stannic 

 ethide by heating stanethyl to 150 C., yet the author could not suc- 

 ceed in obtaining the former body in a state of purity from this 

 source : it seemed probable, however, that stannic ethiodide would 

 be easily converted into stannic ethide by bringing it into contact 

 with zincethyl ; and a preliminary experiment completely realized 

 this expectation. The results of this reaction, together with its ex- 

 tension to other analogous organo-metallic compounds, form the sub- 

 ject of the present Memoir. 



I. Action of Zincethyl upon Iodide of Stanethyl. 



About two ounces of crystals of iodide of stanethyl were gradually 

 added to a strong solution of zincethyl in ether, care being taken to 

 preserve an excess of zincethyl. On submitting the resulting syrupy 

 liquid to distillation, it began to boil at 70 C. ; but the thermo- 

 meter rapidly rose to 180 C., between which temperature and 

 200 C. the greater part of the product passed over, solid iodide of 

 zinc containing a little zincethyl being left in the retort. The di- 

 stillate was washed with dilute acetic acid, and the dense ethereal 

 liquid which separated was dried over chloride of calcium, and recti- 

 fied. The greater portion of it distilled at 181, and was collected 

 apart. Submitted to analysis, it yielded results leading to the 

 formula 



The following equation, therefore, expresses the action of zinc- 

 ethyl upon iodide of stanethyl : 



Sn(C 4 H,)Il _ fSn(C 4 H 5 ) 2 

 Zn(C 4 H 5 )j"lZnI 



Stannic ethide or binethide of tin is a limpid colourless liquid even 

 at 13 C., possessing a very faint ethereal odour, resembling that of 

 oxide of stanethyl, and a slightly metallic, though not unpleasant 

 taste. Its specific gravity is 1 1 87 at 23 C. A determination of the 

 specific gravity of its vapour gave the number 8'02l, showing that 

 stannic ethide consists of one volume of thin vapour and four volumes 

 of ethyl, the five volumes being condensed to two. Stannic ethide 

 boils at 181C., and distils unchanged, thus differing from stannous 

 ethide, which decomposes at 150, chiefly into metallic tin and 



