794 



DEATH. 



Such then are the causes of molecular death. 

 For a history of its phenomena, when partial, 

 \ve must refer to the article MORTIFICATION. 

 Its characters when universal, that is, when the 

 consequence of systemic death, will be con- 

 sidered when we come to speak of the signs of 

 the reality of death. 



SYSTEMIC DEATH. 



Systemic life is constituted by those actions 

 which maintain the mutual dependence of the 

 several parts of the organic whole. Such are 

 the functions which provide new matter for 

 the blood, (digestive secretion and absorp- 

 tion) that which effects a chemical change in 

 the blood, (respiration) that which distri- 

 butes it through the organs and tissues, (cir- 

 culation cardiac, arterial, capillary, and venous) 

 that which removes from the blood effete 

 matters, (excretive secretion) and that which 

 is intimately connected with all these functions, 

 though we are ignorant of the mode of its 

 operation, viz. the function of nervous matter 

 or innervation. The cessation of these actions, 

 and the consequent solution of connection 

 between the various parts of the body, is sys- 

 temic death. With the cessation of the re- 

 maining functions, or those which maintain 

 certain relations between the organic body 

 and objects external to it, constituting the 

 animal life of Bichat, and the relative life of 

 others, we have nothing to do in this place. 

 (See SLEEP.) 



The obstruction of any one of the functions 

 above enumerated must in a longer or shorter 

 space of time bring the others to a termination. 

 .But, as the arrest of the circulation acts upon 

 the other functions immediately, while the 

 latter affect one another merely by the inter- 

 vention of the former, we may very properly 

 consider the causes of systemic death under 

 the general head of Syncope. 



1. Syncope by asphyxia. We shall not 

 stop to inquire in what manner the suppres- 

 sion of respiration arrests the action of the 

 heart, as the question has been very fully and 

 satisfactorily considered in thearticle ASPHYXIA. 

 For the same reason we shall waive the dis- 

 cussion of the accidental causes of this state, 

 viz. strangulation, submersion, &c. &c. The 

 diseases which aie said to produce death by 

 asphyxia are those in which syncope would not 

 supervene when it does, but for the obstruc- 

 tion of the respiration. They are for the most 

 part affections either of the respiratory ap- 

 paratus itself, or of the brain and spinal mar- 

 row ; and it is almost superfluous to add that 

 they prevent the intercourse between the blood 

 and pure air, either by blocking up the air- 

 passages, or by stopping those muscular actions 

 which are essential to a change in the contents 

 of the pulmonary tubes and cells. Certain 

 organic diseases of the heart itself are said to 

 produce death by asphyxia. In these cases 

 there is an obstruction to the motion of the 

 blood through the left side of the heart ; and 

 in the majority of them the asphyxial sym- 

 ptoms are not so much the direct effects of the 

 impediment in the heart, as of the intermediate 

 pulmonary affections, some of the most fre- 



quent of which are bronchitis, oedema of the 

 lung, and pulmonary apoplexy. When, how- 

 ever, a person dies suddenly, with asphyxial 

 symptoms resulting from an arrest of the circu- 

 lation at the left side of the heart, without any 

 intervening derangement in the organs of re- 

 spiration, the case ought not to be considered 

 an instance of genuine asphyxia. The ap- 

 pearances imitative of this state (we allude 

 more particularly to various phenomena be- 

 longing to venous congestion) are not occa- 

 sioned as in true asphyxia by the stagnation 

 of blood in the extremities of the pulmonary 

 arteries, the consequence of its not being 

 arterialized, but by the obstacle presented 

 to the currents in the trunks of the pul- 

 monary veins by the lesion of the heart. 

 In brief, the anatomical difference in the two 

 states is, that in the one the pulmonary arte- 

 ries only, in the other botli these and the 

 pulmonary veins are the seats of congestion ; 

 the physiological distinction is, that in the 

 former the obstruction is chemical, in the latter 

 mechanical. 



2. Syncope by nervous lesions. The various 

 parts of an animal body are bound together 

 by a reciprocity of action, over and above that 

 particular connection which exists between 

 certain organs, and which results from a mu- 

 tual subservience of function. In the latter, 

 the association is perceptible in the normal 

 condition of the body, as, for instance, be- 

 tween the organs of digestion and those of 

 secretion, or of digestion and sanguifaction, 

 or in the sympathetic actions of the respiratory 

 muscles ; but the other species of connection 

 is only or chiefly observed in morbid con- 

 ditions; in other words, it is only when dan- 

 ger is threatened to one organ that the others 

 give tokens of their intimacy and of their 

 interest in its well-being. But for our know- 

 ledge of the existence of this community of 

 feeling (a phrase to be taken only in a me- 

 taphorical sense), it would be impossible to 

 throw any light upon the fatal consequences 

 of a great number of diseases and injuries. 

 There can be little doubt that in all states of 

 the system it contributes very materially to the 

 production of that individuality which is one 

 of the grand characteristics of organic beings, 

 and which becomes more and more obvious as 

 our survey rises to the higher departments of 

 the animal kingdom. There is a manifest in- 

 equality in this respect, even among the su- 

 perior classes of animals. Many lesions that 

 would be fatal to birds and Mammalia, are 

 comparatively trivial to reptiles, not so much 

 because the injured part is of less importance 

 in the functional arrangements of the latter, 

 as because other parts have less sympathy 

 with it. 



There is no subject in the whole range of 

 Physiology more beset with difficulties than the 

 inquiry into the causation of sympathy. Vas- 

 cular connection has been thought by some to 

 explain the secret sufficiently, by others the 

 contiguity or continuity of tissues. Some 

 have seen the media of communication in the 

 ganghonic nerves, others in the nerves called 



