Chap. 4.] 



CHAP. IV. 



OF CARBONIC ACIB GAS; FIXED OR FIXABLE AIR. 



The Bajis of this Air is the elementary Matter of Charcoal Combined 

 with Oxygen.-: Modes of producing it. Fermentation. Quantity 

 contained in different Kinds of Wines. -Choak Damp. Properties of 

 Fixed Air. Great fpecifo Gravity. May lie poured out of a VeJJel 

 like Water Refijls Putrefaction. 



IN enumerating the elementary principles of bodies, 

 it will be recollected, that coal, or carbon (accord- 

 ing to the French chemifts) was confidered as a fimple 

 elementary fubftance. Carbonic acid gas, however, is 

 by no means entitled to this character. It receives 

 the name of carbonic, becaufe its actual bafis is the 

 matter of coal, or, more properly, charcoal. It is 

 called acid, becaufe a quantity of oxygen enters into its 

 compofition. It is denominated a gas, from the mat- 

 ter of fire which gives it the character of a perma- 

 nently elaftic or aeriform fluid. 



As this was the firft of the gaffes which excited the 

 attention of the philofbphers of Europe, it has been 

 diftinguifhed by various appellations. It was at firft 

 only known under the general and uncharacteriftic 

 name of mephitic or (foul) air j when it was found 

 exifting in large quantities in a fixed or folid flate, as 

 in lime, chalk, or alkaline falts, from which it might 

 be expelled by the action of heat, it obtained the name 

 of fixed or fixable airj when by the ufual tefts, and by 

 otherinfallible marks, it was found to pofiefs the cha- 

 racters of an acid, it was called by the learned Bergman 

 VOL. I. C c the 



