JOURNAL 



OF 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND 



THE ARTS. 



FEBRUARY, 1813, 



ARTICLE I. 



An Account of some Experiments on different Comlinations of 

 Fluoric Acid. By John Davy, Esq. From the Philosophical 

 Transactions, 1812. 



Introduction, 



TWO years ago, I engaged, at the request of my brother, Statement of 

 Sir H. Davy, in an inquiry respecting the nature of com- 4 e su jec ' 

 mon fluoric acid gas. My principal object was to ascertain 

 whethersilex is essential to its constitution, and whether the pro- 

 portion is constantly the same. This subject, and experiments 

 on the fluoric and fluoboracic acids, occupied me for about six 

 months. Since that time, the work of MM. Gay Lussac and 

 Thenard has appeared, entitled " Recherches Physico-Chimi- 

 qnes," in the second volume of which is an elaborate disserta- 

 tion on fluoric acid. These philosophers, I find, have anticipa- 

 ted many of my results, and consequently very much abridged 

 my labour of detail in the following pages. To repeat what is 

 already known would be useless j I shall therefore confine myself 

 to describe what I have observed, which appears to me yet novel, 

 or different from the observations of the French chemists. 

 The order which I shall pursue, will be that which I observed 

 in my experiments. I shall divide what I have to advance into 

 Wen,. XXXIV,— No. 15/, G four 



