Royal Society. 539 



attempts to determine the relative strength of affinity by precipita- 

 tion, — in all methods of quantitative analysis founded on the colour 

 of a solution in which colourless salts are also present, — and in all 

 conclusions as to what substances exist in a solution, drawn from 

 such empirical rules as, that " the strongest acid combines with the 

 strongest base." 



March 15, 1855. — The Lord Wrottesley, President, in the Chair. 



The following communications were read : — 



"Researches on Organo- metallic Bodies." By E. Frankland, 

 Ph.D., F.R.S., Professor of Chemistry in Owens College, Man- 

 chester. Second Memoir. — Zincethyle. 



This compound, whose existence was mentioned in a previous 

 memoir*, is formed by the action of zinc upon iodide of ethyle, or a 

 mixture of iodide of ethyle and anhydrous ether, at a temperature ex- 

 ceeding 100° C. The materials are enclosed in a copper digester 

 capable of resisting great pressure. When purified by rectification 

 in an atmosphere of carbonic acid, zincethyle possesses the following 

 properties : — At ordinary temperatures it is a colourless, transparent 

 and mobile liquid, refracting light strongly and possessing a peculiar 

 odour, rather pleasant than otherwise, and therefore differing greatly 

 from that of zincmethyle. Its specific gravity is 1' 182 at 1S° C. 

 Exposed to a cold of — 22° C. it exhibits no tendency to become 

 solid. Zincethyle boils at 118° C, and distils unchanged. The spe- 

 cific gravity of its vapour is 4 - 251. Several analyses of zincethyle 

 prove its formula to be 



C* H 5 Zn. 



The vapour volume of zincethyle is highly remarkable, and almost 

 compels us to conclude that the vapour volume of the double atom 

 of zinc is only equal to that of oxygen, instead of corresponding 

 with the volume of hydrogen, in accordance with the generally re- 

 ceived supposition. Zincethyle, therefore, appears to belong to the 

 so-called water type, and to consist of two volumes of ethyle and one 

 volume of zinc vapour ; the three volumes being condensed to two : 

 for if we were to assume that an equivalent of zinc occupies the 

 same vapour volume as an equivalent of hydrogen, we should then 

 have the anomaly of the combination of equal volumes of two radi- 

 cals being attended by condensation. 



Although zincethyle is remarkable for the intense energy of its 

 affinities, which place it nearly at the head of the list of electro- 

 positive bodies, yet it does not appear to be capable of forming any 

 true compounds with electro-negative elements, its reactions being 

 all double decompositions in which the constituents of the zincethyle 

 separate. Zincethyle is spontaneously inflammable in atmospheric 

 air or oxygen ; but when a few drops, diluted with ether to prevent 

 inflammation, are passed into a mercurial eudiometer containing dry 

 atmospheric air, a rapid absorption of oxygen takes place, with the 

 formation of a white amorphous solid composed of zinc, ethyle, and 



* Philosophical Transactions, 1852, p. 430, 



