GALVANISM, &c. 



THE electricity evolved by the contact of two 

 pieces of metal, such as copper and zinc. It 

 has also been called animal electricity, from its 

 effect on the animal muscle. 



Perpetual Motion. 



M. de Luc invented an electro-galvanic apparatus, 

 for keeping a ball in motion, which, in 1815, had 

 continued in motion for more than two years, and is 

 not known yet to have ceased. The number of 

 vibrations have varied from 45 in a minute down to 

 scarcely one. 



Copper Bottoms. 



Iron nails and pins were formerly used to fasten 

 the sheets of copper to the ships' bottoms ; but since 

 it has been ascertained that the galvanic action pro- 

 duced by the union of these two metals is a cause of 

 destruction, copper nails and pins, which, although 

 not so strong, are not attended with the same incon- 

 veniences, have been substituted. 



A Galvanic Tongue. 



On coating the point of the tongue with tin foil, 

 and its middle part with gold or silver leaf, a sourish 

 taste is produced. 



