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CHAP. II. Death produced by External Causes. 



1. THE modes by which external agents (comprised 

 chiefly in poisons and mechanical injuries) produce death are in- 

 cluded in those which have been assigned as the modes of disease. 

 The difference is, that whereas the origin of death by disease is 

 in progressive causation, predisposition, &c. ; the origin of death 

 by externals is to be considered at the period of their exhibition 

 or infliction. It belongs to specific inquiry to trace the particular 

 relations of the several poisons in the mineral, vegetable, and ani- 

 mal departments. The phenomena of external injuries, also, 

 inasmuch as they differ from those of spontaneous disease, form 

 the subject of a specific analysis. But the general conformity of 

 both with the preceding modes and divisions may be briefly shewn. 

 2. Poisons either destroy life by properties directly related 

 with the principle, so as to render it, by their combination, an 

 unassimilating identity; or else their relation with the diffused 

 organic spirit is not direct, but the vitality of this spirit is de- 

 stroyed by their agency through the medium of a primary influ- 

 ence upon the properties engaged in a function, or upon the 

 material alliances. These are the modes of the operation of 

 poisons, which, it will be seen, are those of disease, and concern- 

 ing which therefore it no more belongs to this place to be particu- 

 lar than to trace the history and varieties, respectively, of every 

 disease which may terminate in death. 



3. Injuries of the mechanical kind, from external causes, 

 may produce either local or universal death. The phenomena 

 in these cases are also reducible to the classes which have 

 been assigned to those of disease. Injuries producing universal 

 death are commonly inflicted upon a functional organ, when death 

 immediately succeeds to such injuries, as upon the brain, heart, 

 spinal marrow, lungs, or great blood-vessels, &c. In these 

 cases, such injuries kill by impairing or destroying the function of 

 the organ on which they are inflicted, or of one holding with it a 

 natural relation of the dependent kind. But injuries sometimes 

 produce speedily universal death, which are inflicted upon seats 

 which are not necessary to the life of the rest of the body ; or, if 



