112 Answer to Dr. Hare's Letter. 



uniformly charged with positive electricity, the amount of which 

 would be 100 as before. 



XV. The action of the two portions of space, as they have just 

 been supposed to be constituted (xiv), is as if they possessed two 

 different specific inductive capacities (1296); but I by no means 

 intend to say that specific inductive capacity depends in all cases 

 upon the number of conducting particles of which the dielectric 

 is formed, or upon their vicinity. The full cause of the evident 

 difference of the inductive capacity of different bodies is a prob- 

 lem as yet to be solved. 



xvi. In my papers I speak of all induction as being dependant 

 on the action of contiguous particles ; i. e. I assume that insula- 

 ting bodies consist of particles which are conductors individually 

 (1669), but do not conduct to each other provided the intensity 

 of action to which they are subject is beneath a given amount 

 (1326, 1674, 1675) ; and, that when the inductric body acts upon 

 conductors at a distance, it does so by polarizing (1298, 1670) alt 

 those particles which occur in the portion of dielectric between 

 it and them. I have used the term contiguous (1167, 1673), but 

 have, I hope sufficiently expressed the meaning I attach to it : — ■ 

 first by saying at par. 1615 " the next existing particle being con- 

 sidered as the contiguous one ;" then in a note to par. 1665, by 

 the words " I mean by contiguous particles those which are next 

 to each other, not that there is no space between them," and, fur- 

 ther, by the note to par. 1164 in the 8vo. edition of my researches 

 which is as follows. " The word contiguous is perhaps not the 

 best that might have been used here and elsewhere, for as parti- 

 cles do not touch each other it is not strictly correct ; I was in- 

 duced to employ it because in its common acceptation it enabled 

 me to state the theory plainly and with facility. By contiguous 

 particles I mean those which are next. 



xvii. Finally, my reasons for adopting the molecular theory of 

 induction were, the phenomena of electrolytic discharge (1164, 

 1343) ; of induction in curved lines (1166, 1215) ; of specific 

 inductive capacity (1167, 1252); of penetration and return ac- 

 tion (1245) ; of difference of conduction and insulation (1320) ; of 

 polar forces (1665), &c. &c. ; but, for these reasons, and any 

 strength and value they may possess, I refer to the papers them- 

 selves. 



