274 DR. E. FRANKLAND’S RESEARCHES ON ORGANO-METALLIC BODIES. 
action is the double sulphide of ethyl and zinc (mercaptide of zinc), which is pro- 
duced as follows : 
There is also formed a little free sulphide of ethyl, according to the following 
equation : 
The aetion of sulphur upon zincethyl is strikingly seen, if vulcanized india-rubber 
joints be used in the apparatus for the preparation of zincethyl ; such joints, even 
when exposed only to the diffused vapour of zincethyl, soon become covered witli 
pustules, which swell up to a large size and burst with slight explosions, until the 
caoutchouc is completely disintegrated. 
This remarkable behaviour of zincethyl in contact with the electro-negative ele- 
ments, cannot fail to have an important influence upon our views of the condition of 
bodies at the moment of chemical change, — a subject so ably discussed by Brodie 
whose ingenious views, I consider, receive a new support from the reactions detailed 
in the foregoing pages. This behaviour also strikingly confirms the suggestions I 
ventured to make in a former memoir -f-, relative to the moleculo-symmefrical form 
of the organo-metallic compounds. In the inorganic combinations of zinc this metal 
unites with one atom only of other elements, a very instable peroxide, not hitherto 
isolated, being the only exception. The atom of zinc appears therefore to have only 
one point of attraction, and hence, notwithstanding the intense affinities of its com- 
pound with ethyl, any union with a second body is necessarily attended by the ex- 
pulsion of the ethyl. 
Action of Water upon Zincethyl. 
1 have already mentioned;!; that water and zincethyl suffer mutual, and almost 
instantaneous decomposition, when brought into contact with each other, being trans- 
posed into oxide of zinc and hydride of ethyl, 
I have, in fact, already made use of this reaction as a means of analysing zincethyl, 
and it is therefore only neeessary for me here to prove the composition of the gas 
evolved. For this purpose, a quantity of zincethyl was gradually decomposed by 
water, and the gaseous product collected. It had all the physieal and citemical pro- 
perties of the hydride of ethyl I have already described §, and yielded the following 
analytical results : 
* Philosophical Transactions, 1850, p. 789. f Ibid. 1852, p. 438. 
I Philosophical I’ransactions, 1852, p. 436. § Journ. of Chem. Soc. vol. ii. p. 288; vol. Hi. p. 341. 
