PRIZE ESSAY. THE EXCITO-SECRETORY SYSTEM OF NERVES. ITS RELATIONS TO PHYSIOLOGY AND PATHOLOGY. BY HENRY FRASER CAMPBELL, M. D., PROFESSOR OF SPECIAL AND COMPARATIVE ANATOMY IN THE MEDICAL COLLEGE OF GEORGIA, ETC. ETC. Observation becomes experiment when used in severe processes MAY, 1857. PRIZE ESSAY. THE EXCITO-SECRETORY SYSTEM OF NERVES. We THE object of the present essay, is to develop more fully a function of the nervous system, which, though enunciated and described nearly seven years ago in this country,' is only now beginning to be fully recognized by the profession in Europe. refer to that function which has been termed the Excito-secretory,3 and which results from the relation subsisting between the excitor or sensitive nerves of the cerebro-spinal and the secretory branches of the ganglionic system. It is by virtue of the particular system of nerves thus resulting, as we hope to demonstrate in the present paper, that a great many of the important acts of nutrition and secretion are modified in circumstances both of health and disease, and further, that it is to aberrations in this particular function that many of the heretofore, mysterious phenomena of diseased action are mainly attributable. The prosecution of this very interesting inquiry is necessarily embarrassed by many difficulties. The generalization of kindred facts, long established in other relations, and made the basis of induction in those relations, when they are now transferred to an 'The Influence of Dentition in producing Disease. By Henry F. Campbell, M.D., Demonstrator of Anatomy in the Medical College of Georgia. Medical and Surgical Journal, vol. vi. p. 321. June, 1850. * London Lancet, American edition. March, 1857. Excito-Secretory System of Nerves. By Marshall Hall, M. D., F.R.S., &c. 3 Vide Transactions of the American Medical Association, vol. vi., art. Sympathetic Nerve in Reflex Phenomena. By Henry F. Campbell, of Georgia. May 3d, 1853. entirely new position, and made to serve as data for evolving a new result, in many instances opposed to those of their former interpreters, will give to our reasoning a character of novelty, which we fear may be stigmatized as innovation by those holding adverse opinions to our own. Then, again, the data for our deductions being scattered throughout the vast domain of medicine, and oftentimes associated with other facts which are entirely irrelevant, it is a matter of no small labor to dissolve these associations, and to place them in their proper and pertinent relations for the deduction we wish here to accomplish. We will, notwithstanding, give ourselves to the uninviting task, even with these forbidding aspects of it frowning upon us, for we are impelled to it by the reflection, that the field is a rich one, that the fruit is ripe and ready for harvest, that the data accumulating for years need only a proper interpretation to make them yield the very results we hope to draw from them, and further, that did we not perform the present duty, many years cannot elapse before some other will give himself successfully to the same important work. THE NERVOUS SYSTEM. The Nervous System, as has been long admitted, is divisible into two grand portions, the Cerebro-spinal and Ganglionic, or to speak physiologically, the nerves of animal life, and the nerves of organic life. In the perfect being, endowed with these two systems of nerves, a multitude of facts, the result both of observation and experiment, go far to establish the belief, that though evidently performing functions in the animal economy of very diverse characters, these two portions are yet intimately connected with each other, and further, that such connection in function, as well as in physical relation, is indispensable to animal unity in those beings who possess both these departments of the nervous system. As in the following essay we shall be required constantly to refer to the actions of these two systems of nerves, it will not be improper, in the beginning, to recall briefly a sufficient number of the admitted facts in relation to their functions, to establish a clear view of their respective parts in the animal economy. Firstly, then, it is to the cerebro-spinal system, with its varied endowments of sensation, motion, special sensation, and perhaps, even intellec tion,' that the being owes his adaptedness for a relation with the objects of the external world. Between the various portions of this great system, while there exist separations and distinctions of the most obvious character, there are also relations mutual and intimate, which are of the first importance to the individual. The senses, endowing him with the aesthetic faculty, enable him to spread before him on the field of consciousness, all which is passing in the world without, while the internal, or intuitive phenomena, complete the contents of this same field. Thus, the sensible world. without, and the world of intellect within, according to some,3 are pictured upon a canvas or blank sheet, and presented to the reason and the judgment, as data by which the being may direct and shape his conduct under the influence of a supreme principle of our organization, the Will. These constitute the voluntary acts of animal life. Then, on the other hand, there are certain muscular acts, equally amenable to the dictates of the will, which are performed independently of the cerebral organs apparently, and without putting in requisition either reason, judgment, or the will, under the influence of the, so to speak, vicarious power of reflex action. This last set of phenomena constitute a body of facts, classed under the general term of excito-motory action, and for the full development of which, science is indebted to the genius and labors of Doctor Marshall Hall.4 The other portion of the nervous system, termed the Ganglionic, Sympathetic, or Organic Nervous System, was, for a long time, a mystery to physiologists, and therefore became the subject of much observation and experiment. The views of Willis, Vieussens, Lancisius,' Winslow, Meckel, Zinn, and Scarpa," having finally given place to the more rational suggestions of Bichat" and 'Herbert Mayo, on the Nervous System. "Mind and Matter," Sir Benjamin Brodie. 2 Consciousness is the accompaniment of all our faculties, and, so to speak, their echo. . . . . Consciousness is nothing else than the rebound of the action of all our faculties.-Victor Cousin, History of Modern Philosophy, vol. i. p. 322. 3 Locke. Lectures on the Nervous System and its Diseases. London, 1836. 6 Nervorum Descriptio et usus. Geneva, 1695. Neurograph Univers, lib. 3 de Nervis, cap. v. 7 De Ganglia Nervorum. 8 Mémoires de Berlin, 1749. 9 Ibid., 1753. 10 Annal. Anatom. de Gangliis. Anatomie générale. |