relative to Light and the eleffric Fluid. 193 
Thus, fire inflames bodies, and throws its particles or light 
atadiítance. Hence, the explofion of gun-powder, and the 
luminous appearance, occafioned. by the electric {park : the fire 
mixt with it producing thofe effects. 
Thus alfo, electricity attracts and repels certain rien bodies 
alternately, under given circumftances. Hence, the alternate 
attraction and repulfion of glafs, ‘and fome other things, heated 
by fire : the electricity mixt with the communicated fire pro- 
ducing thofe effects. 
In this way I would infer the heterogeneoufnefs of light and 
ele&ricity, and their mixture with each other ; and in this way 
account for the fimilitude and difference of their effects ; and 
for the luminous appearance or vifibility of the eleétric fpark in 
particular, without diminifhing the pure electric fluid contain- 
ed in it: all of which, in the cafe referred to, is faid to go 
dire&ly, aud is to be found in the place, to which it was def- 
tined. 
On the fame principles the fhining,of diamonds in the dark 
when rubbed, and thereby ele&rified, may be accounted for, 
without fuppofing they loofe. any art of their matter. 
- In regard to the different colgurs of the electric fpark, which 
are more or lefs ftrong according to the ftrength of the fpark, 
they correfpond to the different colours of light or fire, which 
are more or leís vivid according to the denfity or intenfenefs of 
that element. This famenefs of effet fhews a famenefs of 
caufe, or that the light or fire mixt with the electric {park pro- 
duces thofe colours : whofe ftrength or vividnefs being accord- 
ing to the bignefs of the fpark, or to its quantity of eleétric 
fluid, makes it probable, that in proportion to the quantity, 
there is more or lefs light or fire contained in that fluid. 
Aa Thefe 
