The principles of physiology by John Augustus Unzer; and A dissertation on the functions of the nervous system, by George Prochaska.

  • Johann August Unzer
Date:
1851
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Licence: Public Domain Mark

Credit: The principles of physiology by John Augustus Unzer; and A dissertation on the functions of the nervous system, by George Prochaska. Source: Wellcome Collection.

Provider: This material has been provided by the Gerstein Science Information Centre at the University of Toronto, through the Medical Heritage Library. The original may be consulted at the Gerstein Science Information Centre, University of Toronto.

    29/504 page xi
    xxxvii. Function of the common Sensorium. § 215. That point of the nervous system is termed the common sensorium (Sensorium commune), in which external impressions meet, and from which internal impressions are diffused to all parts of our body; in which, consequently, the consensus of the nerves takes place that is necessary to Life, and in which external impressions are reflected into internal impressions, according to the law of self-conservation (178), with, or without, consciousness. § 216. That sensorium in which impressions are reflected with the consciousness of the soul, may be termed the soul-sensorium ; and the other, the corporeal sensorium; just as Willis has already divided it, into the rational and the corporeal soul. § 217. The brain, only, is the seat of the soul-sensorium; the seat of the body-sensorium is the brain, spinal cord, and (as all obser- vation shows) the ganglia and plexuses of the nerves. That external impressions can also be reflected in the brain, without conscious- ness, is shown by the involuntary convulsions of voluntary muscles. Monsters, born without brain and spinal cord, and which live up to the moment of birth, show that the consensus of the nerves necessary to this form of life, imperfect though it be, may take place, and that there may be a corporeal sensorium independently of the brain and spinal cord, and which, consequently, must be constituted by the plexuses and ganglia of the nerves. The movements observed to take place on irritating the nerves of a headless frog, and seen also in decapitated men, prove the same thing. The sympathetic nerve ap- pears likewise to reflect its impressions in its ganglia and plexuses, without the consciousness of the soul. § 218. In accordance with this consensus of the nerves, as well in the brain as in the spinal cord, ganglia, and plexuses, the operation of a stimulus is not limited to the nerves immediately irritated, but is extended to distant nerves, in known or unknown connection with the irritated nerves ; and this is demonstrated by innumerable examples of consensus of nerves [consensus nervorum], as, for instance, the irri- tation in the pregnant uterus often causes nausea, vomiting, headache, toothache, &c. § 219. Both the soul-sensorium and body-sensorium operate ac- cording to the law of self-conservation (178), a truth which may be illustrated by numerous examples. For instance, the irritation or impression of too strong a light goes to the optic nerve, from whence it can only get at the ciliary nerves through the brain, and induce
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