PROPERTIES OF MUSCULAR FIBRE. 287 



the immediate cessation of the heart's action, in the same manner as a violent 

 injury of the Brain or Spinal Cord. Now it is interesting to remark that, in 

 all these cases, the whole vitality of the system appears to be destroyed at 

 once ; for the processes which would otherwise succeed the injury, and which, 

 after other kinds of death less sudden in their character, produce evident 

 changes in the part of the surface that has immediately received it, are here 

 entirely prevented. An instance is on record, in which a criminal under 

 sentence of death determined to anticipate the law by self-destruction. Having 

 no other means of accomplishing his purpose, he stooped his head and ran 

 violently against the wall of his cell ; he immediately fell dead ; and no mark 

 of contusion showed itself on his forehead. The same absence of the usual 

 results is to be noticed, in the case of blows on the stomach. Yet it is well 

 known, that many of the ordinary vital processes will take place in the injured 

 parts, after death of a more lingering nature ; the vitality of the individual 

 organs not being destroyed, immediately on the severance of the chain which 

 binds together the different functions. 



387. The influence of severe impressions on the Nervous System in dimi- 

 nishing, where it does not altogether destroy, Muscular Contractility, is well 

 seen in the effect of severe injuries affecting vital organs, or extending over a 

 large part of the surface, in depressing the heart's action. This is a well- 

 known result of severe burns, especially in children, whose nervous system is 

 more susceptible of such impressions than that of the adult ; also of the rupture 

 of the alimentary canal, of the bladder or uterus ; and of the shattering of one 

 of the extremities, by violence affecting a large part of their substance. In 

 all these cases, the sufferer is in the same condition with one who has received 

 a severe blow on the head, that does not quite stun him; the shock mime* 

 diately diminishes the muscular contractility of the whole system ; and its 

 influence on the heart, which of course manifests itself most conspicuously, 

 produces a degree of depression, which is frequently never recovered from, 

 and which at any rate renders necessary the employment of stimulants, for 

 the purpose of counteracting this very dangerous effect.* Excessive mental 

 emotion, of a kind not in itself depressing, may occasion the sudden cessation 

 of the heart's action, and a general loss of muscular contractility ; and it is 

 well known that muscular power is greatly diminished by emotions which 

 produce no other direct action. 



388. There is no evidence that Muscular Irritability can be increased by 

 any cause operating through the nervous system. It is quite true that, under 

 the stimulus of alcohol, nitrous oxide, &c., or of some purely mental excite- 

 ment, individuals can perform actions requiring a degree of strength, which 

 they cannot exert under any other circumstances. But it does not hence 

 follow, that the irritability is increased ; since the energy of the action may 

 be due solely to the power of the stimulus, by which it is excited. It is well 

 known that stimulating agents, which thus temporarily increase Muscular 

 power, primarily excite the nervous system ; as is shown by the increased 

 mental activity, which results from the moderate use of alcohol, nitrous oxide, 

 opium, &c. ; and it does not seem necessary, therefore, to go further in search 



* The large quantity of stimulus which can be borne even by children, suffering under 

 severe burns, is very extraordinary. There can be no doubt that many lives have been 

 saved by the judicious administration of them, to an amount which would, a priori, have 

 been judged in itself fatal ; but that. many more have been sacrificed to neglect, even on 

 the part of those whose duty it is to watch the indications with the closest attention. The 

 Author's, observation leads him to believe, that Hospital-Nurses very commonly make 

 up their minds that children, who have met with severe burns, must die ; and that, unless 

 closely watched, they neglect the means of which Science and Experience alike dictate 

 the free employment. 



