114 Answer to Dr. Hare's Letter. 



xxi. As an illustration of my meaning, I may refer to the case 

 parallel with mine, as to the extreme difference of interval be- 

 tween the acting particles or bodies, of the modern views of the 

 radiation and conduction of heat. In radiation the rays leave 

 the hot particles and pass occasionally through great distances to 

 the next particle fitted to receive them ; in conduction, where 

 the heat passes from the hotter particles to those which are con- 

 tiguous and form part of the same mass, still the passage is con- 

 sidered to be by a process precisely like that of radiation ; and 

 though the effects are as is well known extremely different in 

 their appearance, it cannot as yet be shewn that the principle of 

 communication is not the same in both. 



xxii. So on this point respecting contiguous particles and in- , 

 duction across half an inch of vacuum, I do not see that I am in 

 contradiction with myself, or with any natural law or fact. 



xxiii. Par. 1, page 2, is answered by the above remarks, and by 

 viii, ix, X. 



xxiv. Par. 2, page 2, is answered according to my theory by 

 viii, ix, X, xi, xii, and xiii. 



XXV. Par. 3, page 2, is answered, except in the matter of opin- 

 ion (xviii), according to my theory by xvi. The conduction of 

 heat referred to in the paragragh itself, will, as it appears to me, 

 bear no comparison with the phenomenon of electrical induc- 

 tion : — the first refers to the distant influence of an agent which 

 travels by a very slow process, the second to one whose distant 

 influence is simultaneous, so to speak, with the origin of the force 

 at the place of action : — the first refers to an agent which is rep- 

 resented by the idea of one imponderable fluid, the second to an 

 agency better represented probably by the idea of two fluids, or 

 at least by two forces ; — the first involves no polar action, nor 

 any of its consequences ; the second depends essentially on such 

 action ; — with the first, if a certain portion be originally employ- 

 ed in the centre of a spherical arrangement, but a small part ap- . 

 pears ultimately at the surface ; with the second, an amount of 

 force appears instantly at the surface, (viii, ix, x, xi, xii, xiii, xiv,) 

 exactly equal to the exciting or moving force which is still at the 

 centre. 



xxvi. Par. 2, page 4, involves another charge of self-contradic- 

 tion, from which therefore I will next endeavor to set myself 

 free. You say I '^ correctly alledge that it is impossible to charge 



