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luntary actions; therefore this opinion does not appear to me to be such as we should receive with entire confidence. Again, it it is further apparent, that the functions of the abdominal and other viscera are greatly affected by disorders of the brain, and that the brain is greatly affected by disorders of these viscera.
The ingenious and industrious French anatomist, Bichât, has classed, the living functions into the organic and animal: the distinction seems a natural and useful one, and throws light on the physiology of the visceral nerve. In vegetables, and in some moluscae, no traces of a nervous system are discoverable. In some of the lower order of animals, a that have organs for the preparation and distribution of nutriment, they are supplied by a visceral nerve, which it is probable maintains amongst those organs a con
currence of impressions and actions. In some of these animals no traces of nerves subservient to the voluntary regulation of their motions can be found. In the ascending complexity of the nervous system, we find a nervous chord more or less beset with ganglia, which supplies, other parts of the body besides the viscera, and which probably serves to maintain amongst them likewise a concurrence of impressions and actions. We next find at one end of this chord a kind of ganglion, or brain, which gradually becomes larger and more complex as we trace the series of links upwards to man, in whom it bears a much larger proportion to the nervous system in general than in any other animal. The visceral nerve, in the ascending series of animals, appears connected with the animal nerves; and so numerous are these connections that this nerve has in the human subject obtained the title of the great sympathetis 100TWC, -
The vital organs are required to carry on their functions with a degree of regularity and order, under the varying circumstances of life; and the possession of a distinct nerve may enable them to continue their functions without so materially participating in the disturbances of the animal system, as they must otherwise have done: yet the numerous connections of the visceral with the animal nerves must render both participators in each other's disorders. *
The nerves, then, may be said to proceed from the brain, medulla spinalis, and visceral nerve, to all parts of the body for their supply. In thus expressing” a fact, however, we should guard againstan. idea which the analogous distribution of arteries is apt to lengender. Arteries become minute in proportion as they send off branches, whilst on the contrary, the branches of nerves are often larger than the trunk from which they, proceeded. It is no unfrequent occurrence, for malformed, children to be born without a brain, yet, with a perfect nervous system." The most rational idea, therefore, we can entertain on the present subject, is, that the nerves are formed in the parts where we find them, and that they are connected to those parts of the organs from which we are accustomed to say... they proceed. Nerves are vascular, and, we can inject them with subtile injections. ...,
* - o ; , , ; , ; ; ; The nerves, then, proceeding from, or, being connected with the brain, medulla spinalis, and visceral nerve, may be traced, ramifying throughout the body in the manner already mentioned, till they antive
at the part for the supply of which they are designed. They then split into numerous branches which communicate with each other, and again subdivide and rejoin, their communications appearing to multiply as they become more minute; so that every part of the body has a kind of net, work of nerves, which is minute in proportion to the susceptibility and sensibility it possesses. . . . . . . . . " * * * * * * ... . . . . . G. : : This general and imperfect sketch of the anatomy of the nervous system, relates only to what may be discovered by our unassisted sight. If by means of the microscope we endeavour to observe the ultimate nervous fibres, persons in general are as much at a loss as when by the same means they attempt to trace the ultimate muscular fibres. ... . . - . . . “Those fibres which we can split off