43 
chemical Agencies of Electricity. 
perhaps an additional circumstance, in favour of the theory to 
state, that heat and light are likewise the result of all intense 
chemical action. And as in certain forms of the Voltaic 
battery, where large quantities of electricity of low intensity 
act, heat is produced without light ; so in slow combinations 
there is an increase of temperature without luminous ap- 
pearance. 
The effect of heat, in producing combination, may be easily 
explained according to these ideas. It not only often gives 
more freedom of motion to the particles, but in a number of 
cases it seems to exalt the electrical energies of bodies; glass, 
the tourmalin, sulphur, all afford familiar instances of this last 
species of energy. 
I heated together an insulated plate of copper and a plate 
of sulphur, and examined their electricities as their tempera- 
ture became elevated: these electricities, scarcely sensible at 
56° Fahrenheit to the condensing electrometer, became at 
100 9 Fahrenheit capable of affecting the gold leaves without 
condensation; they increased in a still higher ratio as the 
sulphur approached towards its point of fusion. At a little 
above this point, as is well known from the experiments of 
the Dutch chemists, the two substances rapidly combine, and 
heat and light are evident. 
Similar effects may be conceived to occur in the case of 
oxygene and hydrogene, which form water, a body appa- 
rently neutral in electrical energy to most other substances : 
and we may reasonably conclude that there is the same exal- 
tation of power, in all cases of combustion. In general, when 
the different energies are strong and in perfect equilibrium, tiie 
combination ought to be quick, the heat and light intense, and 
G 2 
