150 COMBUSTIBLE ACIDS. 



only in solution in water. It is as volatile as 

 acetic acid, and has a smell somewhat similar to 

 that of that acid. It was this similarity of smell, 

 and the property which it has of forming soluble 

 salts with most of the bases, that led Fourcroy 

 and Vauquelin to the opinion that it was identi- 

 cal with acetic acid. 



Dobereiner has ascertained, that when formic 

 acid is mixed with concentrated sulphuric acid, 

 it undergoes decomposition at the ordinary tem- 

 perature of the atmosphere being converted 

 into water, which combines with the sulphuric 

 acid, and into carbonic oxide, which makes its 

 escape in the form of gas. When it is mixed 

 with nitrate of silver or nitrate of mercury, and 

 a gentle heat applied, the formic acid is equally 

 decomposed j carbonic acid is disengaged, and 

 the oxides are reduced to the metallic state. 

 These curious phenomena are easily observed, 

 and they are sufficient to enable us to distinguish 

 this acid from every other.* 

 Analysis of 2. Berzclius was the first chemist who at- 



formicacid. , , . . ,, * 



tempted to determine the composition or formic 

 acid. He fbundt that anhydrous formate of lead 

 is a compound of 



Formic acid . 100 or 4-696 

 Protoxide of lead 298-1 - 14 



* Gilbert's Annalen der Physick, LXXI. 107- 

 f Annals of Philosophy, IX. 107 



