the rapid inter-mixture of masses of the atmosphere thrown into
circulation by heat. There are some capital descriptions of thunder
clouds. They are often accompanied by whirlwinds, and always by rain. It
is the friction of the whirlwind on the drops of rain that developes
electricity—the rain being positively, and the air negatively,
electrified. Hail is due to the ascending current of air carrying the
drops of water to the region of snow and frost! His notions are somewhat
hazy, thus:—“Much of the positive electricity is conveyed to the earth
by the lightning; but the corresponding negative electricity from being
carried upwards with the vertical wind, cannot so easily escape to the
earth, so that the storm cloud contains, on the whole, more negative
electricity than positive electricity” (p. 38.)