Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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- 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.
This work has been identified as being free of known restrictions under copyright law, including all related and neighbouring rights and is being made available under the Creative Commons, Public Domain Mark.
You can copy, modify, distribute and perform the work, even for commercial purposes, without asking permission.
The image contains the following text:
1. Shows the Anterior or Motor Root of a
Spinal Nerve, such as are given off
from the Cord, between the vertebra.
2. Shows the Posterior or Sensory Root of
every such spinal nerve; which, to-
gether, make it a compound nerve.
3. The Ganglion that connects each of these
with the Great Sympathetic by a 6hort
route.
Fig. 56. A View of a Piece of the Spinal Cord
at natural size; showing the origin of
Bome Spinal Nerves.
Effects of Electric Currents on the Spinal Cord.
By the vivi-section of animals, Professor "Weber has demon-
strated, with the aid of electro-magnetism, that the spinal cord
is the nervous centre of all the muscles of the trunk and ex-
tremities. If one of the electrodes of such a machine, with the
current at maximum, be placed at the upper end of the exposed
cord, while the other is directed to the lower end of the cord,
we find that all the muscles of the body, or of the animal, are
brought into violent tetanic convulsions. The same is true, if
the electrodes are placed, the one to the anterior, and the other
to the posterior roots of the upper portion of the spine, and even
of the lower portion also, if it is yet intact.
Dr. Althaus justly says, if the spinal cord were simply the com-
mon trunk of all the motor nerves that emerge from the vertebral
canal, then electrizing the lower part of the cord should produce a
convulsion of the lower or hinder extremities, but not of all four
extremities. If, however, the spinal cord is cut completely across
transversely, and then only the lower half is Faradaized, the
muscles of the lower or hinder extremities enter into contrac-
tion ; and even if now both parts of the cord are made to touch
each other closely at the transverse section, so that the simple
passage of the electric current to the upper portion of the cord
is easy, yet do the muscles of the upper extremities remain per-
fectly quiet. From this we may fairly infer, that the convulsions
described are not produced simply because the electric current
is transmitted from the cord to the motor nerves, but rather