NEW DEFLAGIIATOR. 161 



with electrified surfaces from the voltaic apparatus is slowly 

 acted upon, and the alkaline, earthy, or acid matter carried 

 to the poles in the common order. Not even the most solid 

 aggregates, nor the firmest compounds, are capable of re- 

 sisting this mode of attack ; its operation is slow, but the 

 results are certain ; and sooner or later, by means of it, bodies 

 are resolved into simpler forms of matter. 



The effects of galvanism on metallic bodies are greatly 

 increased by using plates of a large size ; and on the con- 

 trary, the shock is increased by multiplying the pairs of 

 plates. The shock of a battery containing eighty or a hun- 

 dred pairs of plates, of three or four inches in diameter, is 

 such as few persons would be willing to bear more than once. 

 At the same time such a battery produces but feeble effects 

 when passed through a metallic wire. On the contrary, if 

 one or two pairs of plates containing the same extent of sur- 

 face be used, the sensation it gives is hardly to be felt, while 

 it will deflagrate a metallic wire of considerable size. 



Professor Hare, of Philadelphia, has invented a new me- 

 thod of extricating the Voltaic influence, by so connecting 

 the plates, that, in effect, only two great surfaces of the metals 

 are presented to each other. By this arrangement, the gal- 

 vanic action on different substances has presented some new 

 phenomena, and the common theory of galvanism must un- 

 dergo, it is thought, a radical change. The calorific princi- 

 ple is immensely increased, while the electric shock is hardly 

 to be perceived. Charcoal exposed to the effects of this new 

 deflagrator melts into globules resembling diamond, and the 

 process is attended with a most intense light. If mercury 

 be placed in the hand, and the back side of the hand be ap- 

 plied to the negative pole, and the positive pole be brought 

 to the surface of the mercury, it will be inflamed, and the 

 hand will be affected with no disagreeable sensation, till the 

 mass of mercury becomes heated. The new view, which 

 Professor Hare has been induced to offer, is, that galvanism 

 is a compound of electricity and caloric, and this is thought 

 to be confirmed by the action of his machine. 



Questions. — 1. What is the most convenient kind of galvanic 

 battery ? 2. What is the effect of a powerful galvanic battery upon 

 inflammable substances ? 3. Describe the battery at the Roj^al Insti- 

 tution in London. 4. What effect does it produce upon charcoal.? — 

 other substances ? 5. What is said of the effects of galvanism by 

 14* 



