396 Pbilofopbtial Fireworks. [Book V. 



by mixing an equal quantity of this air with atmofpheric 

 air, a flame of a blue colour will be produced ; the 

 pure hydrogen from metals furnifties a red flame ; 

 and if by breathing, fome carbonic acid gas or fixable 

 air is added, the flame will appear beautifully tinged 



with purple *. 





 * See BriUbn, torn. ii. p. 81. 



