Second Letter from Dr. Hare to Prof. Faraday. 13 



important as respects a correct idea of the direction, as their length 

 has been shown by Wheatstone, to be incompetent to produce 

 any perceptible delay. 



The dissipation of conductors being one of the most prominent 

 among electrical phenomena, it appears to me to be an objection 

 to your theory, if, while it fails to suggest any process by which 

 this phenomenon is produced, it assumes premises which seem to 

 be incompatible with the generation of any explosive power. If 

 discharge only involves the restoration of polarized ponderable 

 particles to their natural state, the potency of the discharge must 

 be proportionable to the intensity of the antecedent polarity ; yet 

 it is through conductors, liable, as you allege, to polarization of 

 comparatively low intensity, (xxxi,) that discharge takes place 

 with the highest degree of explosive violence. 



Having inquired how your allegation could be true, that dis- 

 charge brings bodies to their natural state and yet causes con- 

 ductors to be dissipated, you reply (xxxiv,) that different effects 

 may result from the same cause acting with different degrees of 

 intensity ; as when by one degree of heat ice is converted into 

 water, by another into steam. But it may be urged, that although 

 in the case thus cited, different effects are produced, yet that the 

 one is not inconsistent with the other, as were those ascribed to 

 electrical discharges. It is quite consistent, that the protoxide 

 of hydrogen which per se constitutes the solid called ice, should 

 by one degree of calorific repulsion have the cohesion of its par- 

 ticles so counteracted as to be productive of fusion ; and yet that 

 a higher degree of the same power should impart (o them the re- 

 pulsive quality requisite to the aeriform state. In order to found 

 upon the influence of variations of temperature, a good objection 

 to my argument, it should be shown, that while a certain reduc- 

 tion of temperature enables aqueous particles to indulge their 

 innate propensity to consolidation, a still further reduction will 

 cause them, in direct opposition to that propensity, to repel each 

 other so as to form steam. 



In your concluding paragraph you allege, " that when pon- 

 derable particles intervene, during the process of dynamic in- 

 duction, the currents resulting from this source do require these 

 particles." I presume this allegation is to be explained by the 

 conjecture made by you (1729) that since certain bodies when 

 interposed did not interfere with dynamic induction, therefore 



