an oo al 
ters, 
in different chemical Processes on Fluor Spar. 415 
decompose the fluoric acids, by combustible substances, 
can lead to no other result, than that of occasioning new 
combinations of the fluoric principle; and the only me- 
thods which seemed plausible for obtaining this principle 
pure, after that by electrical decomposition had failed, were 
by the action of oxygen or chlorine on certain of its com- 
pounds. Chlorine is, in certain instances, detached from 
hydrogen by oxygen; and oxygen, in a2 number of cases, 
is detached from metals by chlorine: [ thought it therefore 
probable, that the fluoric principle might, in some process, 
be separated from bases by either chlorine or oxygen. 
In selecting compounds for experiments of this kind, I 
was guided by the relative attractions of the fluoric and 
muriatic acids, of chlorine and oxygen. Horn silver ané 
calomel, and muriate of potassa are not decomposed by 
fluoric acid; but fluate of silver, of mercury, and of potassa 
are easily decomposed by muriatic acid: I therefore con- 
ceived, that the fluoric principle would most likely be ex- 
pelled from the dry fluates of silver, mercury, and potassa 
by chlorine. 
I made some pure fluates of silver and mercury, by dis- 
solying the ‘oxides of these metals in fluoric acid, and E 
heated them in small trays of platina; much fluoric acid 
was driven off in this process, which [ continued in the 
case of the fluate of mercury till the salt began to sublime, 
and in that of the fluate of silver till it was red hot. 
The dry salts were introduced in small quantities into 
glass retorts, which were exhausted and then filled with 
pure chlorine: the part of the retort in contact with the salt 
was heated gradually till it became red. There was soon a 
strong action, the fluate of mercury was rapidly converted 
into corresive sublimate, and the fluate of silver more slowly 
became horn silver. In both experiments there was a vio- 
Fent action upon the whole of the interior of the retort. 
On examining the results, it was found that in both in- 
stances there had been a considerable absorption of chlorine, 
and a production of silicated fluoric acid gas, and oxygen 
gas. 
I tried similar experiments, with similar results, upon dry 
fluates of potassa and soda. By the action of a red heat, 
they were slowly converted into muriates with the absorp- 
tion of chlorine, and the production of oxygen, and silicated 
fluoric acid gas, the retort being corroded even to its neck. 
The obvious explanation of these phenomena is, that a 
particular principle, the acidifying matter of the fluoric 
acid, combined with the metals, is cxpelled from them by 
the 
