82. ie Notices of Tornadoes, &c. 
Ill.—On Tornadoes, and Girsted’s Memoirs respecting them. 
, To the Editors of the National Gazette. 
_ Dear Sirs,—I believe it is generally admitted by electricians 
that the enormous discharges of the electric fluid, which, during 
f ‘thunder gusts, take place in the form of lightning, are the conse- 
quence of the opposite electrical states of an immense stratum of 
the atmosphere coated by the thunder clouds, and a corresponding 
portion of the terrestrial surface. In a memoir published in the _ 
5th volume of the American Philosophical Transactions, repub- ~ 
lished in Silliman’s Journal, vol. 32, for 1837, I had endeavored 
to show that the tornado was the consequence of the same causes 
producing in lieu of lightning, an electrical discharge by a verti- 
cal blast of air, and the upward motion of electrified bodies. In 
your Gazette of the 30th ult., you have republished an article by 
the celebrated C&rsted, in which it is alledged that tornadoes or 
water-spouts cannot be caused by electricity, because there is no 
evidence proving that persons exposed to them have experienced 
electrical shocks. 'T'o me it appears evident that the scientific 
author confounds the different processes of discharge to which I 
have alluded, the one occurring in thunder gusts, the other in 
tornadoes ; also that he has forgotten that a shock can be given 
neither by a blast of electrified air, nor by a continuous electrical 
current, a transient interruption of the circuit being indispensable 
to the production of the slightest sensation of that nature. If a 
person, having a conducting communication between one of his 
hands and a charged surface of a well insulated battery, hold in — 
the other hand ie sieteieas wire, the battery will be ‘discharged 
through him and through the wire, producing a blast of electri- 
fied air from the point, without his experiencing any shock ; nei- 
ther would a shock be given to any person by exposure to the f 
blast thus produced. 
This form of electrical discharge to which I ascribe tornadoes, 
in which electricity is conveyed from one surface to another by 
the motion of air or other movable bodies intervening, is by Fat 
aday designated as “ convection,” from the Latin “conveho,” t0 
carry along with. 
In the comparatively minute experiments of electricians, the 
of convective discharge, is exemplified not only by the 
electrified aerial blast, but likewise by the play of pith balls, the 
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