132 



Messrs. Knox on the Insulation of Fluorine. 



The Action on the variotis Metals by Fluorine, Hydro-fluoric Acid, and Fapour of 



Fluoride of Mercury. 



It is right to state here, that the action on the palladium and bismuth was 

 not proved to be from the formation of fluorides of those metals, . in consequence 

 of the minuteness of the pieces used. That on the gold vfe have since confirmed 

 by the action upon it by the battery. 



In order to determine the relative attraction of fluorine for those metals upon 

 which it does not seem to act except in the nascent state, we made platinum, 

 palladium, gold, and rhodium successively constitute the positive pole of a battery 

 of sixty pair of plates, electrolizing moistened fluoride of lead. The platinum 

 was covered with a chocolate-coloured substance, which disappeared on heating. 

 The action on the palladium gave rise to a reddish-brown colour, the same as 

 that obtained before by the direct action of the gas. The gold was only occa- 

 sionally acted upon, — the colour, brownish-red. The rhodium was never acted 

 upon in the trials we gave it ; so that if this should be confirmed, fluorine might 

 probably be obtained in an insulated state by electrolizing a fluoride, using 

 rhodium as the positive pole. 



We repeated M. Baudrimont's experiments in glass, and in the vessels of 

 fluor spar, but were unable to obtain a coloured gas having the properties which 

 he describes. From the nature of his experiments, we conceive it to be impos- 

 sible that the gas obtained by M. Baudrimont could be fluorine, on account of 



