28 NOMOS. 



idea is naturally suggested by the phenomena of 

 the voltaic battery. It was first enunciated by Sir 

 Humphry Davy in a Bakerian Lecture in 1806, 

 and again in 1826, when he stated " that chemical 

 and electrical attraction were produced by the same 

 cause, acting in the one case on particles, in the 

 other on masses, of matter ; and that the same pro- 

 perty, under different modifications, was the cause 

 of all the phenomena exhibited by different voltaic 

 combinations." * In this, however, as in almost every 

 other question connected with electricity, it required 

 a Faraday to give us definite information. 



There is no manner of doubt that the energy of 

 voltaic electricity is proportionate to the energy of the 

 chemical action in the cells of the battery. When 

 these cells are charged with brine, the action is 

 stronger than when they are charged with water; 

 and when they are charged with sulphuric acid, it 

 is stronger still : that is to say, the powers of de- 

 composition, the deflecting influence upon the mag- 

 netic needle, and the vividness of the spark, are all 

 directly related to the activity of the chemical 

 changes in the cells of the battery. All this is 

 allowed. 



Now the changes in the cells of the battery, so 

 far as we can ascertain, are purely chemical. Under 

 ordinary circumstances, for example, the zinc plate 

 is oxidised at the expense of the water in the cell, 

 and the zinc and water are decomposed in equivalent 

 proportions. In one of Dr. Faraday's experiments, 

 8*45 grains of zinc were oxidised and dissolved, and 



* " Philosophical Transactions," 1826, p. 389. 



