258 Chemistry. [Lecture 33. 



even issuing from springs, which have a peculiar 

 taste and smell. When these properties are to 

 such an excess that the waters cannot be applied 

 to domestic purposes, they are distinguished by 

 the name of mineral waters. 



The substances usually found in these waters 

 are about thirty-eight in number, and may be 

 reduced to the four following heads: 1/Air; 

 2, Acids ; 3, Alkalies ; 4, Neutral salts. 



1. Atmospheric air is often contained in waters, 

 but its proportion is seldom above one-twenty- 

 eighth part. Oxygen gas is also found in incon- 

 siderable quantities, as well as nitrogen gas. 



II. Acids. Of these carbonic acid is the most 

 common ingredient, and gives briskness to the 

 water, like that of a fermenting liquor ; this brisk- 

 ness appears most when the water is poured from 

 one vessel into another; it is sometimes, how- 

 ever, so considerable as to burst a corked bottle. 

 This acid, in the form of gas, is sometimes em- 

 ployed to give other wines a resemblance to 

 Champaign. It is extremely volatile, and soon 

 flies off; for, if we expose the water containing 

 it to the air, it loses its briskness : we can pro- 

 mote its separation by shaking the vessel ; when 

 the cork frequently flies out with an explosion. 

 An artificial water of this sort may be produced 

 at any time. 



2. Sulphurous acid has been observed in se- 

 veral of the hot mineral waters in Italy, in the 

 neighbourhood of volcanoes. Sulphuretted hy- 



