OF NATURAL PHILOSOPHY. 331 



tained from expansion more or less completely by 

 non-conductors. It is supposed, moreover, that this 

 electric fluid possesses a power of attraction for the 

 particles of all ponderable matter, together with 

 that of a repulsion for particles of its own kind. 

 Whether it has weight, or is rather to be regarded as 

 a species of matter distinct from that of which pon- 

 derable bodies consist, is a question of such delicacy, 

 that no direct experiments have yet enabled us to 

 decide it; but at all events its inertia compared 

 with its elastic force must be conceived excessively 

 small, so that it is to be regarded as a fluid in the 

 highest degree active, obeying every impulse, in- 

 ternal or external, with the greatest promptitude ; 

 in short, a fluid whose energies can only be com- 

 pared with those of the ethereal medium by which, 

 in the undulatory doctrine, light is supposed to be 

 conveyed. The properties of hydrogen gas com- 

 pared with those of the denser aeriform fluids will, 

 in some slight degree, aid our conception of the 

 excessive mobility and penetrating activity of a 

 fluid so constituted. Electricity, however, must be 

 regarded as differing in some remarkable points from 

 all those fluids to which we have hitherto been ac- 

 customed to apply the epithet elastic, such as air, 

 gases, and vapours. In these, the repulsive force 

 of the particles on which their elasticity depends is 

 considered as extending only to very small distances, 

 so as to affect only those in the immediate vicinity 

 of each other, while their attractive power, by 

 which they obey the general gravitation of all 

 matter, extends to any distance. In electricity, on 

 the other hand, the very reverse must be admitted. 



