166 FLUORIC ACID AND ITS COMPOUNDS. 



and white on the outside, as if they had been 

 coated over with silica. The fluoric acid had 

 made its escape, and had corroded the whole of 

 the surface of every one of the phials. 



SECT. I. 



OF THE ATOMIC WEIGHT OF FLUORIC ACID. 



THE properties of pure fluoric acid have been 

 detailed with great accuracy by Gay-Lussac 

 and Thenard, arid by Sir H. Davy. I have no- 

 thing to add to the statements of these eminent 

 chemists, except to say that I found them all 

 quite exact so far as I repeated them. 



1. The only person who has attempted to de- 

 termine the atomic weight of fluoric acid, so far 

 as I know, is Berzelius. And it will be worth 

 while, before I detail the experiments which I 

 have myself made, to state those of this most 

 laborious and accurate experimenter. He en- 

 deavoured to determine the atomic weight of 

 this acid by analyzing fluate of silver, fluate of 

 barytes, and fluate of lime, each in as pure a 

 state as he could prepare them. 



(1.) 4*936 parts of fused fluate of silver left, 

 mentsto when dissolved in water, O185 of metallic silver 



of so that the quantity of fluate of silver actually 

 fluoric add. dissolved was 4-751 parts. This solution being 

 precipitated by sal-ammoniac, furnished 5'349 



