2Q APPENDIX. 



39. As the ganglia of the great sympathetic form an independent system presiding 

 over certain functions which are essentially vital, consequently they may be viewed as 

 the system and seat of organic life, and may, therefore, be denominated the vital system 

 of nerves, whose centre is the semilunar ganglion.* 



40. It seems probable, from the circumstances of a separate ganglion or plexus, or 

 both, being generally assigned to each important secreting or animalizing organ, that the 

 centre or source of vital influence does not supply the whole vitality distributed by the 

 ganglial ramifications to the individual organs and textures ; but that the vital influence 

 proceeding from this centre is reinforced by that which is produced by the subordinate 

 ganglia, and is not only reinforced, but modified by them, and by their distributions in 

 the various organs, so as to give rise to the specific difference of function which each 

 performs ; and that the vital manifestations of particular ganglia are still farther modified 

 by the communicating branches between them and the cerebro-spinal system, the ex- 

 tent of modification being relative to the extent to which the nerves of this latter sys- 

 tem either communicate with, or contribute to supply, or to form, the individual subor- 

 dinate ganglia. 



Lastly. The vital influence, being thus produced from the centre of the body, and" 

 reinforced and modified by the subordinate ganglia, allotted to the individual organs, 

 accm-ding to their functions", is propagated along the distributions of the system, on which, 

 it depends and is inherent, throughout the whole body. 



systems inquired into, and the irritability of the latter class of vessels contended for, 

 and shown to be derived from this cause D. Evidences of their influence over the se- 

 creting viscera and textures, a. On the gastric secretions and functions, b. Their con- 

 trol over the secretions from mucous and other surfaces, and from follicular glands, c- 

 Over the biliary and pancreatic secretions, d. Over the secretions and functions of the 

 urinary organs. E. Their influence on the mass of blood circulating through the heart 

 and blood-vessels, a. As regards the changes induced in this fluid during respiration. 

 b. As respects the phenomena which it displays, after having been drawn from an arte- 

 ry and vein in the general circulation, during various states of the system, c. The power 

 of these organs in the production of animal heat. 



2. The functions of these organs, viewed in connexion with the muscular fibres of 

 involuntary motion. 3. The probability of their being the chief source of irritability 

 contended for, and the varying characters of this principle explained, as it is displayed 

 in the different muscular textures and capillary vessels. 4. The influence of the brain 

 and spinal cord, upon the operations of the organs under consideration, viewed, a. 

 In respect to the manner and extent in which the former affect the contractions of the 

 heart. 6, As they (the voluntary nerves) ntay affect the capillary circulation of a part, 

 and proofs of their limited influence over the vascular ramifications, c. With regard 

 to the small extent of power which the brain and spinal cord can exert over the func- 

 tions of digestion, unless through the medium of the ganglions. 5. A general view of 

 the phenomena to which the ganglial ramifications give rise, when reinforced by the 

 nerves properly so called. 6. The manisfestations to which they give rise in the infe- 

 rior classes of the animal creation. 7. The functions of the ganglions, as they regard 



the generative process, a. In the male. b. In the female 8. Their influence in the 



formation and nutrition of the textures ; and in the progress and decay of the animal, 

 considered. 9. The effects produced on different animals, by the application of certain 



substances to the expansion of these organs 10. The consideration, that the manifes- 



taions essentially vital are the result of these organs, entertained, argued for, and ex- 

 plained from the inferences deduced from the foregoing sections. 11. A general view 

 of the doctrines contained in this part of the treatise. (Land. Med Repos. for Jlfaij, 

 1822.) 



* Violent blows or contusions on the epigastric region, when they do not immediate- 

 ly destroy the individual subjected to them, depress in a very remarkable manner the 

 vital energies of the system.' The animal heat is uncommonly diminished ; the surface 

 is cold and pale ; the pulse slow, and scarcely perceptible ; and the breathing feeble 

 and very slow. An analogous effect in some respects, is produced by concussion of 

 the semilunar ganglion, as that which follows concussion of the brain : in the former the 

 vital or organic actions are either exhausted or destroyed, in the other animal or volun- 

 tary operations only are suspended. 



