flame, the flash,
or the chain of lightning, and probably the aurora.

4th. Evolving heat.--Melting metallic substances by concentration, with a
great intensity of heat--as the wire of the galvanic apparatus, and as is
sometimes seen in the effects of lightning in fusing metals on persons
stricken; and setting combustibles on fire.

5th. Attraction and repulsion.--Attraction, when the currents flow
parallel with each other, or are of opposite natures, and repelling when
of like character.

6th. Induction.--Inducing attendant circular or other secondary currents,
such as may be seen in the atmosphere during its most violent displays of
active energy.

7th. Capable of being dissipated by heated air, or carried off by
moisture, although isolated by dry air, of ordinary temperature, which is
a bad conductor.

Now, although magnetism can not be collected, imprisoned, or discharged,
like electricity, or collected at all, but by its adherence to some
substance capable of magnetization, it is obvious there is an intimate
association, at least, between it and electricity. _They are never found
alone._ All _electricity_ will _magnetize_. All _magnetism_ will evolve
electricity. All _currents_ of _electricity_ have _encircling currents_ of
_magnetism_, and all deflect the magnetic needle. All magnetic currents
give out to intersecting wires, _currents of electricity_, and all magnets
_induce_ them.

Electricity, therefore, whether identical in substance with magnetism, but
differing in form, or whether merely associated with it, as is variously
believed, should be present with magnetism in greater quantity or
intensity where magnetism is most intense, and active, and whenever
present, should be active and influential. And so we find, from
observation, the fact to be. No inconsiderable effort has been made by the
advocates of the caloric and mechanical theories, to ignore the agency of
electricity and of magnetism, in the production of the varied
meteorological phenomena. But it will not do. The phenomena, grouped and
analyzed, disclose a potential-controlling, magneto-electric agency, and
meteorology will advance rapidly to perfection, as a simple, intelligible,
and practical science, _as soon as that agency is admitted_.

Electricity is always perceptibly present in storms and showers within the
tropics. Most of the rain, from the tropical belt, falls from "thunder
showers." So hurricanes and typhoons, and all tropical st