Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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quantity and intensity; by the Barometer
and other instruments, for ascertaining the
atmospheric density, humidity, ozone, &c.;
or by the Thermometer, for its heat and cold.
Such like meteorological observations made
with much care, and that by all these
present helps for testing and comparing the
normal and abnormal electricities, and
other states of the atmosphere, together
with another class of observations for de-
termining the magnetic variation in the
earth, — simultaneously made on the land
and on the sea, on different continents, in
the extreme north and extreme south, as
well as at the equator, — are to any philo-
sophic, or logical mind, full of significance, as relating to health
and disease, life and death, in the great human family.
We will only remark very briefly, that with regard to the real
electric state of the atmosphere, and of the terrestrial globe,
philosophers have long differed. But of late, Arago and De la
Rive have concluded and do now assume, that our globe possesses,
at least on its solid surface, an excess of accumulated negative
electricity, and that this is the same with bodies on its surface';
that the atmosphere itself, on the whole, is positively electrized,
and arises from the same source as the negative of the globe.
They noticed that when the most highly charged storm clouds
approach mountains, the clouds go towards them with a rush,
and with that quickness in proportion as the summit of the
mountains have the more marked negative tension. They are
then observed to linger, and adhere as it were to the mountain,
as if indifferent or slow conductors, yielding successively either
electricity. This, we notice, is observed only in respect to static
electricity. If, now, we consult the galvanometer, we find phe-
nomena for study in dynamic electricity. For when the cloud
approaches the mountain, and as it commences to pass, the in-
strument gives indications of ascending currents, because the
electricity of the ground is found to be attracted towards the