171 different chemical Processes on Fluor Spar, 267 



Three hypotheses may, according to sound analogies, be 

 formed on the nature of the fluoric combinations. In the first, 

 which is that generally adopted, the silicated fluoric acid gas is 

 supposed to be a compound of silica and a peculiar acid, itself 

 consisting of inflammable matter and oxygen ; fluo-boric acid 

 gas, a compound of boracic acid and the same acid ; and pure 

 liquid fluoric acid as water combined with the acid. 



In the second hypothesis, that which I have alluded to in 

 the beginning of this paper, and that adopted by M. Ampere, 

 the silicated fluoric acid is conceived to consist of a peculiar 

 undecompounded principle, analogous to chlorine and oxy- 

 gen, united to the basis of silica, or silicum; the fluo-boric 

 acid of the same principle united to boron ; and the pure liquid 

 fluoric acid as this principle united to hydrogen. 



In the third hypothesis, which probably would have been 

 formed by the disciples of the phlogistic school of chemistry, 

 had they been acquainted with the facts, the liquid fluoric acid 

 is considered as an undecompounded body; and the metals 

 and inflammable bodies as compounds of certain unknown 

 bases with hydrogen : silicated fluoric acid gas, on this idea, 

 must be regarded as a compound of the fluoric acid with the 

 basis of silicum, and fluo-boric acid gas as a compound of 

 fluoric acid and the basis of boron. 



Whoever will consider, with attention, the different facts 

 that have been brought forward by Scheele, Gay Lussac 

 and Thenard, John Davy, and myself, will find that they 

 will admit of explanation on either of these hypotheses ; and, 

 as in all the cases yet brought forward, of the most simple 

 chemical action of other bodies on the fluoric substances, more 

 than one new form of matter is produced, no explanation of 



MDcccxiii. N n 



