5* Chemistry. [Lecture 25. 



some of these possessing acid properties. This 

 gas is named CHLORINE, and used to be termed 

 Dephlogisticated Muriatic or Qxymuriatic Acid, 

 being supposed to be a combination of oxygen 

 with muriatic acid. This gas being mixed with 

 an equal quantity of hydrogen gas a sour com- 

 pound is formed, commonly called muriatic acid 

 gas, but which is really a hydrochloric acid gas. 



The muriatic or chloric acid is the basis of 

 common salt, hence called muriat of soda. It 

 also combines with potass, ammonia, and many 

 of the earths and metals, forming muriats or 

 chlorats. 



IODINE is another of the acidifying principles. 

 It is obtained by adding sulphuric acid to a so- 

 lution of Kelp, and exposing it to heat, when the 

 iodine rises in purple fumes which condense in 

 opaque crystals, with a metallic lustre. By the 

 action of chlorine on iodine the chloriodic acid 

 is formed. 



IX. The ALKALIES are properly only two, but 

 are generally treated as being three in number. 

 Two of them, potass and soda, are termed the 

 Jlxed alkalies; because they do not rise or be- 

 come volatile by heat : the third, ammonia, 

 is called the volatile alkali, for the opposite 

 reason. 



Potass, the hydrate of Potassa, was formerly 

 called the vegetable alkali, because it was ob- 

 tained from the ashes of land vegetables, and 

 was never found in a mineral state. Soda was 



