53 



When an internal inflammation is of small extent*, and is seated in a 

 part in which there are not many nerves, and whose tissue yields easily to 

 the humours which irritation determines into it, the whole morbid action 

 takes place in the affected part, and the general order of the functions is 

 not sensibly deranged. But when inflammation takes place in a part en- 

 dowed with much sensibility, or of a close texture, as the fingers and toes, 

 then fever comes on, because a sympathy in the morbid action takes place, 

 between the diseased part and the rest of the system. The diffusion of 

 the local action almost infalliby takes place, when inflammation occurs in 

 one of the organs of the assimilating functions. This effect may be con- 

 sidered as uniform, though Morgagni mentions several instances of in- 

 flammation of the liver, marked by no peculiar symptoms. 



A knowledge of the great sympathetic nerves accounts for this differ- 

 ence. When an external part is affected with inflammation, the irritation 

 which it suffers, is by means of its nerves propagated to the brain, which 

 by a re-actionf; called by Vicq-d'Azyr (who on this subject has only de- 

 veloped the opinions of Vanhelmont) internal nervous action, transmits 

 that irritation to the heart, to the organs of respiration, of digestion, and 

 of secretion, in which the phenomena, denoting a febrile state, are prin- 

 cipally evolved. When, on tiie contrary, the heart, the lungs, or any 

 other internal organ is affected with acute inflammation, all the viscera 

 partake in the derangement with which any one of them is affected, and 

 without the intervention of the brain. They are all intimately connected 

 by the filaments which they receive from the great sympathetic nerves? 

 and, by means of that. nervous system, which is in an especial manner ap- 

 propriated to them, they carry on a more intimate intercourse of sensa- 

 tions and affections. Besides, the derangement of the important functions 

 entrusted to the diseased organs, is necessarily attended with appropriate 

 changes in all the acts of the animal csconomy, in the same manner, no 

 doubt, as the defect of one wheel interrupts or disturbs the mechanism of 

 the whole machine:}:. 



* A thousand pustules in the small-pox occasion only a moderate degree of fever, if 

 they are at a distance from each other ; but if the disease is confluent, that is, if the 

 pustules are close together, and run into each other, the fever becomes considerable, and 

 the patient's life endangered. The fleshy granulations which sprout in abundance from 

 an ulcerated surface, are so many small phlegmons unaccompanied by a febrile state, 

 but if brought close to each other by irritation, that condition will not fail to ensue. 

 Vaccination is not, in the greater number of cases, attended by the slightest febrile ac- 

 tion, if, as I always have done, the punctures are made at a certain distance from each 

 other, so that the inflammatory areolse may not run into each other. luthor's Note. 



| The cerebral re-action appears to be in no measure necessary to the induction of 

 symptomatic fever : it may, however, contribute to its continuance. The irritation ap- 

 pears to be propagated to the heart in consequence of the numerous connexions which 

 this organ holds, by means of the ganglial nerves,, with the other viscera ; and owing to 

 the continuous reticulation of these nerves upon the blood-vessels from the heart to the 

 capillary terminations. Copland. 



$ The late experiments, performed on the nervous system by that excellent anatomist 

 and physiologist, Charles Bell, have kd to some very interesting conclusions, and have 

 thrown much light on a very obscure subject. He arranges the nerves in the following 

 manner. There are a number of nerves arising from the spinal marrow by double roots, 

 which pass out laterally to the regular divisions of the body, never taking a course longi- 

 tudinally. These nerves are common to all animals from the worm up to man, and are 

 for the common purposes of sensation and volition. These are termed regular nei*vea; 

 each having two roots, one from the anterior and the other from the posterior division 

 of the medulla spinalis. The 5th pair ; suboccipital ; seven cervical ; twelve dorsal ; 

 five lumbar and six sacral constitute thirty-two (kuble, perfect, orregular nerves. The 



