I 46 3 



a. Fixed Air is difcovered in water by its 

 fparkling, on agitation, and bubbles of air being 

 given out from it. 



b. By its pungent and acid tafte. 



c. Tin&ure of litmus added to it, is chang- 

 ed from its blue colour to a red. 



d. On its being added to lime water, white 

 clouds are formed. The fixed air combining 

 with the lime forms chalk, which not being folu- 

 ble, is precipitated in a fine white powder. 



e. By boiling it, the fixed air is expelled, and 

 the quantity contained in any portion of water 

 may be meafured, by conveying it through a tube 

 into lime water,, and collecting the precipitated 

 chalk; every 30 grains of which contains 18 

 grains and I of fixed air. 



2. AERATED SODA. 



Mineral Alkali combined with fixed air. 



2. AERATED SODA. < 



Synonymous Names. 

 Marine alkali. 

 Mineral alkali. 

 Foffil alkali. 

 Natron or natrum. 

 Soda. 



Bafe of marine fait. 

 Effervefcent foda. 

 Mephite of foda. 

 Chalk of foda. 

 Cretaceous foda. 



This 



