ELECTRICITY. 51 



Electric Attraction and Repulsion. 

 When two light substances receive the same elec- 

 trical influence, or are electrified by the same body, 

 they repel each other, but when one of them is acted 

 on by wax and the other by glass, they attract each 

 other. Hence it is said that bodies similarly electri- 

 fied repel each other, while bodies dissimilarly elec- 

 trified attract each other. 



Supply and Time. 



Electricity is not expended by shocks, and its 

 effects take place in no sensible time. A discharge 

 through a circle of four miles was found to be quite 

 instantaneous. 



Characteristic of the Gazeous Elements. 



A distinguished characteristic of the gazeous ele- 

 ments (chlorine, oxygen, iodine, and fluorine) is 

 that when a compound, consisting of one of them and 

 one of the other forty-nine more passive elements, 

 (metals, earths, &p.) is exposed to voltaic electriza- 

 tion, the former is uniformly evolved at the positive 

 or vitreo-electric pole, while the latter appears at the 

 negative or resino-electric pole. 



Chemical Affinity and Electricity. 



Bodies that have chemical affinity for each other 

 are in different states of electricity ; the one being 

 negative and the other positive. In all the changes, 

 the acid matter collects round the positively electri- 

 fied surface, and the alkaline round the negatively 

 electrified surface. 



Acids To the positive ? c f 

 Alkalies To the negative j surlaces - 

 E 2 



