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Note: This text has been automatically extracted via Optical Character Recognition (OCR) software. The text has not been manually corrected and should not be relied on to be an accurate representation of the item.
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does not dip into the convolutions of the brain * There are three great divisions of the brain . 1 . The cerebrum is the uppermost and by much the largest portion : it is separated into two hemispheres , each of which is divided into
three parts , called lobes . 2 . The cerebellum which lies at the under , and back part of the skull , and is divided into two portions by the descending fold of the * dura naater . 3 . The third division is called the medulla oblonyata : it lies at the base of the skull , and is a continuation of the substances
of the other two divisions . The spinal marrow proceeds without interruption from this third division of the T > rain ; it passes out of the head by the great opening of the skull , and running down the canal of the backbone , where it is safely lodged , giving
off nerves till it reaches the pelvis , where it splits into numerous threadlike nerves , resembling a horse ' s tail : the spinal marrow , like the brain , ' consists of the same sort of substance , and is protected by a continuation of the membranes belonging to that
organ . The nerves arise froin the brain and spinal marrow : they come out in pairs and are distributed over the ^ vhole body . 1 . To bestow an acute aenaation in the instruments of sense . 2 . To give the utmost facility of motion to the instruments of motion : and
3 . To confer in all other parts a nice perception of whatever gives pain . ** If any persdn , " s £$ s Galen , " shall attend to dissections and consider attentively how nature has not distributed the nerves in equal measure to all the different parts of the body ,
but to some more abundantly , and to others more sparingly , he will find himself compelled to acknowledge that nature is eminently wise , just , skilful and provident in her arrangeft ttient of the animal economy . There are forty pairs of nerves : of these nine
pair arise from the base of the brain within the skull ; a tenth from the brain ^ as it passes through the great hole of the skull into the spine , and tHe remaining thirty take their rise
from the spinal marrow . Those arising from the brain are chiefly distributed to the organs situated in the head , and to those contained in the chest and belly , while those that proceed from the spinal marrow go partly
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among the internal organs * 6 f ' the trunk , to be distributed chiefly to the exterior parts of the body and to the limbs . Though the nerves run out in pairs , front their origin , they soon separate to go to different parts of the body , by splitting in innumerable ramifications .
To describe these nerves , and point out their several ramifications would take us much beyond the bounds assigned to these papers , but a single instance will illustrate the nature and uses of the whole , and this shall -be taken from the fifth pair of nerves ,
which is branched to the ball , t | ie muscles , and glands of the eye ;——to the ear—to the jaws , the gums and teeth : —to the muscles of the lips : — to the tonsils , the palate , the tongue , and other parts of the mouth : — -to the prcecordia also , or parts situated about the heart and stomach , by
cdtning in contact with one of its nerves , and finally to the muscles of the face , particularly the cheeks . Herice there is a great consent and sympathy between the parts , so that certain things seen or smelt excite the appetite , affect the glands and parts of the mouth , and in some instances excite
what is known by the phrase of water in the mouth : some things seen or heard affect the cheeks with modest blushes ;—on the contrary , if a thing pleases or tickles the fancy , it affecis the praecordia , and the muscles of the mouth and face with laughter i
others causing sadness and melancholy exert themselves upon the praecordia , and shew themselves by causing the glands of the eyes to emit tears , which by a most wise provision of nature are intended not only to brighten the cornea ; and to express grief , but to alleviate sorrow : " Fletus cerumnas
levatf" and the muscles of the face put on the gloomy aspect of crying . Hence also the passions of anger , of hatred , of malice and envy , of love , of joy and hope are all produced , and exhibited by the countenance , so that , in fact , it is by means of this communication of the nerves , that whatever affects the mind is demonstrated
spontaneously by a consentaneous disposition of the praecordia within , and a suitable configuration of the muscles and other parts of the face without . It is , says Piiny , an admirable contrivance of the great God of nature , that the race should be given to man ,
Untitled Article
Natnral ThtblMg . N& . XII . —Of tte Brain and JVeFt ?** . ig
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Citation
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Monthly Repository (1806-1838) and Unitarian Chronicle (1832-1833), Jan. 2, 1816, page 19, in the Nineteenth-Century Serials Edition (2008; 2018) ncse.ac.uk/periodicals/mruc/issues/vm2-ncseproduct2448/page/19/
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