37« Sir H. Davy on the Substances produced 



I attempted to electrize the liquid fluoric acid, by making 

 plumbago the positive surface ; but the plumbago was quickly 

 destroyed, a subfluate of iron was deposited on the negative 

 surface, and the liquid became turbid and black. When a point 

 of charcoal attached to a wire of platina was made positive, 

 the effects were similar to those produced by a platina wire 

 alone, for the acid speedily penetrated through the pores of 

 charcoal, and tjie platina, in consequence, became a point of 

 contact with the fluid. 



I applied the power of the great Voltaic batteries of the 

 Royal Institution to the liquid fluoric acid, so as to take sparks 

 in it. In this case, gas appeared to be produced from both the 

 negative and the positive surfaces ; but it was probably only 

 the undecom pounded acid rendered gaseous, which was 

 evolved at the positive surface, for during the operation the 

 fluid became very hot, and speedily diminished. The manner 

 in which the surrounding atmosphere became filled with the 

 fumes of the fluoric acid, rendered it, indeed, very difficult to 

 examine the results of any of these experiments ; the danger- 

 ous action of these fumes have been described by M. M. Gay 

 LussAc and Thenard, and I suffered considerable inconve- 

 nience from their effects during this investigation. By mere 

 exposure to them in their uncondensed state, my fingers be- 

 came sore beneath the nails, and they produced a most painful 

 sensation, which lasted for some hours, when they came in 

 contact with the eyes. 



The phenomena of the Voltaic electrization of fluoric acid, 

 present no evidences in favour of its containing a peculiar 

 combustible substance and oxygen; and the most simple 

 mode of explaining them, is by supposing the fluoric acid, like 



