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the effects of the injury to contiguous parts of the nervous system, 

 upon which the formation of the blood depends, as to those parts 

 at least which are necessary to mechanical respiration. 



11. To define then with greater precision our conclusions 

 upon this subject, 



1. The life which assimilates in the nervous system, as in the 

 mixed structures, is every where independent of spiritual properties 

 which live in distant spheres. 



2. If the assimilating life of one sphere is affected or destroyed 

 by an injury or a cause which operates primarily upon the life of 

 another seat, this happens by a new relation, conformably with a 

 new or foreign state, which has been produced on the spirit by the 

 operation of such cause or injury. 



3. There are two ways in which the preternatural condition of 

 a primary, may influence the secondary seat of change : one is direct, 

 as by communication of foreign spiritual properties ; the other is 

 indirect, as by an influence on the formation or circulation of the 

 blood, with which the spirit in every sphere holds a common relation 

 of dependence. 



4. The assimilating life is always affected in the direct mode 

 by additional or preternatural properties: the functional life may 

 be affected or destroyed by foreign properties conferred, or by pri- 

 vation of natural communicated ones; in either of the latter cases 

 the essential change is of the assimilating life, upon it all phenomena 

 ultimately depend. To extend a little our illustration. 



12. An injury of one part of the spinal marrow, or an injury 

 of one part of the brain, may be directly extended to that cerebral 

 portion, the assimilating life of which furnishes the functional pro- 

 perties of the diaphragm, and are necessary to respiration; the life 

 of this portion being thus modified, respiration ceases, and death is 

 then extended, in the mediate way, to parts which have no relation 

 with the primary seat of the injury. Thus also in an injury of an 

 extremity, as a fracture of the leg, the local state of vital properties 

 is extended to those which govern the movements of the heart, the 

 pulsations of which in the course of a few hours are increased, per- 

 haps from 70 to 130 in a minute : properties which govern the 

 caliber and phenomena of the vessels of the brain, might from the 

 same extension of preternatural influence assume that state which 

 constitutes phrenitis. In short, from the interchange of these two 

 modes of affection, the direct and the mediate, complex changes 

 and relations may be variously exhibited, and they furnish a history 

 in almost every seat, which is to be traced only by a specific investi- 

 gation. This matter might be pursued more minutely: the time 

 which elapses in the succession of these phenomena is a point of 

 important but of difficult explanation, it belongs however more pro- 

 perly to the subject of disease. 



13. It would appear that an inquiry into the physiology of any 

 given portion of the nervous system can scarcely be separately pur- 

 sued- The complexity here hinted at must occur in the investiga- 



