140 A«ID9. 



LESSON 64. 



Acids and Salts. 



Acids which contain different quantities of oxygen are distin- i 

 guished by their termination. The name of that which con-  

 tains most oxygen ends in ic, the other in ous. Thus we say ^ 

 sulphuric acid, and sulphurous acid. All salts that are com-  

 posed of acids ending- in ic, take an ending in ate ; as sulphate 1 

 of lime, a compound of lime with sulphuric acid. All salts [ 

 composed of acids ending in ous, take an ending in ite, in- i 

 stead of ate ; as sulphite of lime. When there is an excess J 

 of acid, the preposition super is added ; and when an excess of | 

 the base, then sub is prefixed, as super-sulphate of potasji, or I 

 sub-boratc of soda, (borax.) t 



The name acid, in the language of chemists, has been • 

 given to all substances, whether liquids or solids, which pro- ; 

 duce that sensation on the tongue which we call sour. Most j 

 of the acids owe their origin to the combination of certain 1 

 substances with oxygen ; and they have the property of | 

 changing the blue, green, and purple juices of vegetables to \ 

 red, and of combining with alkalies, earths, or metallic oxyds, i 

 so as to compose those compounds termed salts. The acids <| 

 were formerly divided into three classes, mineral, vegetable, ; 

 and animal ; but the more useful and scientific v/ay of di- ; 

 viding them is into two classes only. The undecomposable ■] 

 acids, and those which are formed with two principles, are ' 

 comprised in the first class ;. while those acids which are form- ; 

 ed with more than two principles compose the second class. | 



Sulphuric acid is procured by burning sulphur, in contact * 

 with some substance containing oxygen ; by which process - 

 the sulphur combines with the oxygen, and becomes acidi- \ 

 fied. In commerce it is commonly called the oil of vitriol. 

 That peculiar acid which is called muriatic is usually ob- \ 

 tained from muriate of soda, which is the chemical name | 

 for common salt. Carbonic acid is a combination of carbon •] 

 and oxygen. It was formerly called fixed air, en account j 

 of its being so intimately combined in chalk, lime-stone, and f 

 other substances. If you pour some diluted sulphuric acid I 

 over pulverized chalk or marble contained in a glass ves- | 

 sel, which has a tube connected with it, an effervescence j 

 will take place, and carbonic acid gas will escape through j 

 the tube, This gas is more destructive of life than any ; 



