315 



Action of Zinc-ethyl on Iodide of Stan-ethyl. 



This iodide, C 4 H 5 Sn, I, was readily obtained by heating sealed 

 tubes containing excess of tinfoil and iodide of ethyl from 150 to 

 160 C. The pure transparent crystals which were obtained by a 

 little management, were introduced, in a melted state, into a retort 

 containing zinc-ethyl. It is necessary to cool the apparatus with 

 water. After breaking up the resulting mass, the retort was heated 

 until the thermometer marked 210 C., and the distillate, which con- 

 tained a slight excess of zinc-ethyl, was agitated with water, and 

 treated with dilute acid, as before described. 



The resulting heavy liquid was again distilled, and fractionized 

 with the thermometer. By far the larger portion came over between 

 170 and 180 as a clear and colourless body, insoluble in water, but 

 soluble, like the other radicals, in ether. That section which pos- 

 sessed a boiling-point between 176 and 180 C., was taken for 

 examination, and was found, when burned with oxide of copper, to 



give the formula 



bn C 8 H 10 , or cm (C 4 U.) 2 . 



This compound, for which the name stannic bis-ethyl is proposed, has 

 a specific gravity of 1*192. In its external and more prominent 

 characters it resembles plumbic bis-ethyl ; but an exception may be 

 made, that it is more stable. It is very combustible, burning with 

 a coloured flame and scintillation like that exhibited by the metal tin 

 under the flame of the hydro-oxygen blowpipe. 



This radical appears to differ in several particulars from the 

 organo-metal stan-ethyl, C 4 H. Sn, obtained by Dr. Frankland by 

 acting on sheet-zinc with a salt of stan-ethyl. This last body is 

 described as a thick, oily substanne, possessed of a powerful odour, 

 and having a specific gravity of T55. It differs also in its lower 

 boiling-point, which is about 150 C. 



Pure stannic bis-ethyl is perfectly limpid, inodorous, and is acted 

 upon by hydrochloric acid with difficulty. A gas is slowly evolved 

 on the application of heat, and a chloride is formed which seems to 

 be richer in tin than the radical itself. 



The chloride appears to crystallize with difficulty, and at usual 

 temperatures has the consistence of an oil. It possesses a powerfully 

 pungent odour, and when heated, a vapour which painfully attacks 

 the skin of the face, and produces fits of sneezing. 



