Answer to Dr. Hare's Letter. 1 17 



charge ; any one of which may cause the discharge of the jar, or 

 the discharge of the inductive arrangements described in this 

 letter (xxx) ; the action of the particles in any one of these cases 

 being entirely different from the mere return action of the polari- 

 zed particles of the glass of the jar, or the polarized globe B (v) 

 to their first state. My view of the relation of insulators and con- 

 ductors, as bodies of one class, is given at 1320, 1675, &c. of the 

 researches ; but I do not think the particles of the good conduc- 

 tors acquire an intensity of polarization any thing hke that of the 

 particles of bad conductors, on the contrary I conceive that the 

 contiguous polarized particles (1670) of good conductors discharge 

 to each other when their polarity is at a very low degree of in- 

 tensity, (1326, 1338, 1675.) The question of, why are the me- 

 tallic particles dissipated when the charge is sufficiefitly powerful — 

 is one that my theory is not called upon at present to answer ; 

 since it will be acknowledged by all that the dissipation is not 

 necessary to discharge ; that different effects ensue upon the sub- 

 jection of bodies to different degrees of the same power is com- 

 mon enough in experimental philosophy : thus one degree of heat 

 will merely make water hot whilst a higher will dissi]pate it as 

 steam and a lower will convert it into ice. 



xxxii. The next most important point, as it appears to me, is 

 that contained in the third and fourth paragraphs of page 5. I 

 have said, (1330.) "what, then, is to separate the principle of 

 these two extremes, perfect conduction and perfect insulation, 

 from each other ; since the moment we leave in the smallest de- 

 gree perfection at either extremity we involve the element of per- 

 fection at the opposite end ?" and upon this you say, might not 

 this query be made with as much reason in the case of motion 

 and rest ? — and, in any case of the intermixture of opposite quali- 

 ties may it not be said, the moment we leave the element of per- 

 fection at one end, we involve the element of perfection at the 

 opposite ? may it not be said of light and darkness, or of opaque- 

 ness and translueency ? and so forth. 



xxxiii. I admit that these questions are very properly put, not 

 that I go to the full extent of them all, as for instance that of 

 motion and rest, but I do not perceive their bearing upon the 

 question of whether conduction and insulation are different prop- 

 erties dependent upon two different modes of action of the par- 

 ticles of the substances, respectively possessing these actions ; or 



