CONDENSATION OF GALVANIC ELECTRICITY. 651 



a piece of blotting paper, folded several . times and 



saturated with water, or salt water, which acts better 



than pure water. The 



paper plays no part in 



the development of elec- 



tricity, it is there to 



prevent direct contact 



between the two metals ; 



for if direct contact were 



to take place, the sepa- 



rated electricities would 



recoinbine instead of 



moving to the two plates 



of the condenser. 



The electromotive 

 force called into action 

 when contact takes place 

 between the liquid and 

 the two metals can, as has already been stated, produce 

 only a very small tension, and can only generate very 

 inconsiderable quantities of electricity in each metal 

 plate. When these plates are connected with the con- 

 denser, the greater portion of the electricity of each kind 

 which is generated passes from them to the plates of the 

 condenser, where they both become bound by their 

 mutual attraction. Electricity is thereby withdrawn 

 from the two metals, but as the action of the eleotromo^ 

 tive force continues, new quantities are, generated which 

 again flow off to the condenser \ an$ this goes on until 

 the tension in the lfttes qf the co,n.dei}ser, 



FIG. 335 (an.proj.; % real size). 



ing that the two electricities a.re mutually bounc} by 



each other, h^s become as great as it was before in 



