* 
12 a Ltier from Dr. Hare to Prof. Faraday. 
When I adverted to a gradual relinquishment of electricity 
by the air to the glass, I did not mean to suggest that it was at- 
tended by any more delay than the case actually demonstrates. 
It might be slow or gradual, compared with the velocity of an 
electric discharge, and yet be extremely quick, comparatively 
with any velocity ever produced in ponderable matter. That the 
return should be slow when no coating was employed, and yet 
quick when it was employed, as stated by you, (xxxviii,) is pre- 
cisely what I should have expected; because the coating only 
operates to remove all obstruction to the electric equilibrium. 
The quantity or intensity of the excitement is dependent alto- 
gether upon the electrified surfaces of the air and the glass. 
You have cited (1632,) the property of a charged Leyden jar, as 
nsually accoutered, of electrifying a carrier ball. This I think 
sanctions the existence of a power to electrify by “convection,” 
the surrounding air to a greater or less depth; since it must be 
evident that every aérial particle must be competent to perform 
the part of the carrier ball. 
Agreeably to the Franklinian doctrine, the electricity directly 
accumulated upon one side of a pane repels that upon the other 
side. You admit that this would take place were a vacuum to 
intervene; but when ponderable matter is interposed, you con- 
ceive Bech particle to act as does the body B when situated as 
described between A and C, (iv.) But agreeably to the view 
which I have taken, and what I understand to be your own ex- 
position of the case, B is altogether passive, so that it cannot help, 
if it does not impede the repulsive influence. Moreover it must 
be quite evident, that were B removed, and A approximated to C, 
without attaining the striking distance, the effect upon C and the 
consequent energy of any discharge upon it from A, would be 
greater instead of less. If in the charge of a coated pane the 
intermediate ponderable vitreous particles have any tendency to 
enhance the charge, how happens it that, the power of the ma- 
chine employed being the same, the intensity of the charge which 
can be given to an electric is greater in proportion to its tenuity ? 
In reference to the direction of any discharge, it appears to me 
that as, in charging, the fluid must always pass from the cathode 
to the anode, so in reversing the process it must pursue, as I have 
alleged, the opposite course of going from the anode back to the 
cathode. Evidently the circumvolutions of the circuit are as un- 
