A critical and experimental essay on the circulation of the blood; especially as observed in the minute and capillary vessels of the Batrachia and of fishes / [Marshall Hall].

  • Hall, Marshall, 1790-1857
Date:
[1844]
Catalogue details

Licence: Public Domain Mark

Credit: A critical and experimental essay on the circulation of the blood; especially as observed in the minute and capillary vessels of the Batrachia and of fishes / [Marshall Hall]. Source: Wellcome Collection.

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    At ten minutes after seven o clock, a very fine wire was passed from the part of the medulla covered by the spinous process of the third vertebra, to the bottom of the spinal canal and withdrawn towards one side. The respiration and the circula- tion in the web were unaltered. The wire was then introduced again and moved about in every direc- tion until there was no longer any spasmodic motion of the limbs. The respiration and circu- lation still continued perfect. At eleven o’clock these functions still continued good. At eight o’clock in the following morning, and at the same hour in the evening, twenty-four hours after the destruction of the spinal marrow, the respiration and circulation still continued good. This experiment does not succeed equally well with the eel. At half-after nine o’clock, a fine wire was passed into the spinal canal of an eel, just below the medulla oblongata, and downwards so as to destroy the spinal marrow. The circula- tion in the tail was immediately enfeebled; the beat of the caudal ventricle ceased, the respiratory acts continued. At eleven o’clock all circulation in the tail had disappeared, but that of the pectoral fin, and the acts of respiration con-