82 SODA. 



of detonating when inflamed with charcoal or 

 other easily inflammable bodies. 



It is upon this property that gunpowder is formed, 

 which consists of five parts of nitrate of potash, one 

 of charcoal, and one of sulphur. Chlorate of potash 

 is formed by passing chlorine gas through a solu- 

 tion of caustic potash. It is also called oxy-mu- 

 riate of potash. This salt detonates violently when 

 three parts of it mixed with one of sulphur are tri- 

 turated in a mortar, or struck on an anvil. With 

 phosphorus the effect is still greater. It makes a 

 powerful gunpowder when employed as an ingre- 

 dient. 



If a small quantity of it be mixed with some 

 sugar, and sulphuric acid be added, a sudden and 

 vehement inflammation will be produced. These 

 experiments require great caution. 



SODA. 



This has also been called the fossil or mineral 

 alkali, because supposed peculiar to the mineral 

 kingdom. It is obtained chiefly from the ashes of 

 marine plants ; all the fuci yield it in abundance ; 

 when burnt, their ashes are called kelp, which con- 

 tains a considerable proportion of this alkali. Ba- 

 rilla is the same, procured by burning a plant of 

 that name in Spain. Soda is also found in large 

 quantities in different parts of the earth, particu- 

 larly Egypt ; and common sea-salt consists of it 

 united to muriatic acid. 



In all these cases, however, the soda is com- 

 bined with carbonic acid. Of this there are two 

 varieties, the carbonate, obtained by dissolving the 

 soda of commerce and crystallizing it, and the bi- 



