Conductors of Electricity, and during Electrolysis. 2*15 



68. We have thus arrived at the general conclusion, that 

 the heat 'which is evolved by the proper action of any vol- 

 taic current is proportional to the square of the intensity of 

 that current, multiplied by the resistance to conduction 'which it 

 experiences. From this law the following conclusions are di- 

 rectly deduced : — 



69. 1st. That if the electrodes of a galvanic pair of given 

 intensity be connected by any simply conducting body, the total 

 voltaic heat generated by the entire circuit [provided always 

 that no local action occurs in the pair) will, whatever may be 

 the resistance to conduction, be proportional to the number of 

 atoms [whether of water or of zinc) concerned in generating 

 the current. For if the resistance to conduction be diminished, 

 the quantity of current will be increased in the same ratio, and 

 hence, according to the law (68.), the quantity of heat which 

 would thus be generated in a given time will be also propor- 

 tionally increased; whilst of course the number of atoms 

 which would be electrolyzed in the pair will be increased in 

 the same proportion. 



70. 2nd. That the total voltaic heat which is produced by any 

 pair, is directly proportional to its intensity, and the number of 

 atoms which are electrolyzed in it. For the quantity of current is 

 proportional to the intensity of the pair, and consequently the 

 quantity of heat evolved in a given time is proportional to the 

 square of the intensity of the pair, but the number of atoms 

 electrolyzed is proportional, in the same time, to the simple 

 ratio only of the current, or of the intensity of the pair. 



71. And 3rd. That when any voltaic atrangement, whether 

 simple or compound, passes a current of electricity through any 

 substance, whether an electrolyte or not, the total voltaic heat 

 which is generated in any time, is proportional to the number of 

 atoms which are electrolyzed in each cell of the circuit, multi- 

 plied by the virtual* intensity of the battery. 



72. Berzelius thinks that the light and heat produced by 

 combustion are occasioned by the discharge of electricity be- 

 tween the combustible and the oxygen with which it is in the 

 act of combination ; and I am of opinion that the heat arising 

 from this, and some other chemical processes, is the conse- 

 quence of resistance to electric conduction. My experiments 

 on the heat produced by the combustion of zinc turnings in 

 oxygen, (which, when sufficiently complete, I shall make public) 

 strongly confirm this view ; and the quantity of heat which 

 Crawford produced by exploding a mixture of hydrogen and 



* If a decomposing cell be in the circuit, the virtual intensity of the 

 battery is reduced in proportion to its resistance to electrolyzation. 



T2 



