OXYGEN. 145 



will burn with the utmost brilliancy, producing a light 

 which the eye can scarcely bear. 



338. The white fumes which fill the 



VFha t acid re- 

 sults from this bottle in this experiment, are composed of 



experiment? part i c i es o f phosphoric acid, which are 

 produced by the union of the phosphorus and oxy- 

 gen. They collect on the sides of the vial, and soon 

 dissolve in water, which they absorb from the air. 

 The water will be found to possess a sour taste, and 

 to redden blue litmus paper, which is a characteristic 

 of acids. 



339. COMBUSTION OF CHARCOAL. At- 



Descnbe the 



experiment tach a small piece of charcoal to 



with charcoal? & fine wire , ignite Qne end of ^ 



thoroughly, and introduce it into a vial of ox- 

 ygen, having a cork at the other end, as 

 before. It burns with brilliant sparks. A piece 

 of charcoal bark is best adapted to this pur- 

 pose. 



340. Carbonic acid is formed in the 



What is pro- 

 duced in this above experiment, from the union of 

 experiment ? car b on w i t h oxygen. It is a gaseous acid, 

 and cannot be seen. Neither can it be detected by 

 its taste. But a piece of moistened litmus paper, held 

 for some time in the bottle, will be reddened by it, and 

 proof of the presence of an acid may be thus obtained. 

 When wood burns, it also yields carbonic acid. 



341. DEFINITION OF COMBUSTION. All 



Dciine com- /. ,, , . /. 



bustion. f tne above experiments are cases of 



combustion, and combustion may be den- 

 ned as combination of any two substances, attended by 



7 



