Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
45/740
- Publication/creation
- Boston : Ticknor and Fields, 1861.
- Physical description
- 3 unnumbered pages, 716 pages, 2 leaves of plates : illustrations ; 26 cm
- Contributors
-
Garratt, Alfred C. (Alfred Charles), 1813?-1891
Harvey Cushing/John Hay Whitney Medical Library
- Notes
-
3d ed. has title: Medical electricity
Includes index and testimonials
- Type/technique
- Electronic books
- Subjects
-
Electrophysiology
Electrotherapeutics
- Attribution and usage
-
This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.
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The image contains the following text:
3. During the different months, generally, the electricity of
the air is more powerful when the sky is serene than when it is
cloudy, excepting towards the months of June and July, when
the electricity attains its maximum ; the value of which is nearly
the same, whatever be the state of the sky.
Thus, setting out with these views, the electricity of the at-
mosphere during a serene sky exceeds the electricity observed
during a cloudy sky, and so much the more as we approach
nearer to January. In this latter month the ratio is more than
four to one. Now, this powerful atmospheric electric intensity,
during the serene sky of winter, is a very remarkable circum-
stance. This has been again and again proved by philosophers,
who have been especially engaged in observing the phenomenon
of atmospheric electricity, but who appear to give it a less rela-
tive value.
Storms.
Mr. Quitman has collected tables of observation made during
extraordinary circumstances, such as in times of snows, rains, and
fogs. He finds that under certain conditions, a powerful electric
atmosphere obtains at the approach of a rain storm, and after a
rain storm, which is sometimes positive and sometimes negative.
The electric intensity observed during fogs has a mean, the same
as that obtained during snows, and is not much influenced by
the time of season. The value of electricity observed during a
tranquil rain, differs very little from the mean taken in the
course of the whole year. The electricity of the air estimated
at an elevation always the same, suffers a diurnal variation,
which generally shows two maxima and two minima; and these
are displaced according to the different epochs of the year. The
first happens before 8 o'clock in the morning in the summer,
and at about 10 A. M. in the winter. The second maximum is
after 9 P. M. in the summer, and about 6 P. M. in winter. The
day minimum is found to be about 3 P. M. in summer, but near
to 1 P. M. in winter. The night minimum is as yet not so
exactly obtained.
Observations accurately taken at all even hours Greenwich