'4^8 Mr. R. Laming on Electric Conduction 



each atom of matter sufficient electricity to envelope it. In 

 the second place, we know, by facts, that the force by which 

 electricity is attracted by matter is greater at shorter distances; 

 from whence it follows that the electricity around an atom of 

 matter will approach to it as near as possible, thus forming a 

 sphere of which the atom is the centre. Again, by the theory 

 of solidity, a mass of electrical matter, or electricity, may be 

 regarded as composed of electrical atoms, just as a mass of 

 ordinary matter contains ordinary atoms; and thus the sphere 

 of electricity which surrounds an ordinary atom will consist 

 of a number of electrical atoms arranged in concentric strata. 

 The number of electrical atoms belonging to a given ordinary 

 atom may be assumed to be such as to complete its external 

 spherical stratum, or, on the contrary, it may be such as to 

 leave that external spherical stratum more or less imperfect. 

 Now, in the former of these two cases, where the sphere of elec- 

 tricity has an unbroken surface, we have all the conditions ne- 

 cessary for electrical insulation ; and in the latter case, where 

 the surface of the sphere of electricity is broken, we have all 

 the conditions essential to electrical conduction. jf? 



To explain this more fully we may begin with conductors. 

 Imagine a line of ordinary atoms, each of which naturally has 

 on the bounding surface of its mass of electricity ten electrical 

 atoms ; and place the ends of this line in connexion with two 

 bodies oppositely electrified. Thereupon so many of the 

 electrical atoms of the plus charge as can find room will place 

 themselves in the broken electrical stratum of the first ordi- 

 nary atom of the conductor; because when there a certain 

 part of each electrical atom then in that stratum, in the ag- 

 gregate amounting to ten whole atoms, will be attracted by 

 the said ordinary atom. This manifestly is required by the 

 law of force, which is greater at the lesser distance ; and be- 

 cause the aggregate of all the parts is at a less distance than 

 are any ten whole atoms in the same stratum. At the other 

 end of the conducting line the negative body will be appro- 

 priating to itself the ten superficial electrical atoms naturally 

 belonging to the most proximate ordinary atom of the con- 

 ductor ; because this atom, in its turn, can make an equal 

 demand upon the next in succession, that one on its neigh- 

 bour, and so onward continually to the plus end of the line, 

 •without at any time the attractive force being called upon to act 

 at an increased distance. The first ten plus atoms being thus 

 virtually discharged into the minus body, a second similar 

 number will then be transferred in like manner, and after that 

 a third, and thus the conducting action will be repeated as 

 many times as is requisite to convey the whole electrical 



