GALVANISM. 3Q3 



But this great quantity of electricity produced 

 by galvanism renders it the most powerful of all 

 chemical agents. All inflammable substances are 

 attracted by the negative pole, and the supporters 

 of combustion or acidifying principles are attracted 

 by the positive pole. Hence some consider the 

 natural state of the electricity of inflammable sub- 

 stances as positive, since it is attracted by the 

 negative ; and that of the supporters of combustion 

 as negative, since they are attracted by positive 

 electricity. 



When this apparatus was employed, if two pieces 

 of charcoal were attached to the opposite wires and 

 brought together, a bright spark appeared, and 

 ignition of the charcoal : if then they were slowly 

 separated by means of the apparatus, (Plate 25. 

 fig. 9.,) an arch of intense fire, four inches in length, 

 was produced, in which all metals burned with great 

 facility, and many very refractory substances were 

 fused. 



The Voltaic pile communicates the greatest de- 

 gree of divergence to the electrometer when pure 

 water alone is used ; but diluted acids which act 

 chemically on the plates, occasion it to produce 

 most ignition, and the greatest shocks. 



Its power of giving shocks, or the intensity of 

 the electricity, increases according to the number 

 of alternations ; but the quantity of electricity is 

 increased by extending the surface of the plates. 



This was admirably illustrated by the apparatus 

 constructed by Mr. Children, at his laboratory at 

 Tunbridge. The plates were 6 feet long, and 2 feet 

 8 inches wide; they were suspended and immersed 

 in troughs, containing diluted sulphuric and nitric 

 acids. Wires of platina were fused instantly, and 



