158 REPORT— 1866. 



perimental inquiry, it is conceived that it may be most efficiently discussed 

 in its various bearings by an attempt to support the following propositions, 

 mainly derived from the study of phenomena which are best and most con- 

 stantly seen in cold-blooded animals, but which nevertheless, under favour- 

 able circumstances, may be observed in warm-bloods, and, in special patho- 

 logical conditions, in the case of man himself : — 



1. That the property of ii'ritabihty in muscle is capable of a high de^ee 

 of exaltation above the normal standard, and that the highest degree of sus- 

 ceptibility is attained in cold-bloods long after death, or under conditions 

 tantamount to death, as before defined. 



2. That the forces of nerve and muscle, the neimlity of the former and 

 the irritability of the latter, are not only independent of each other for their 

 existence and maintenance, but actually possess an antagonistic relation; 

 that is to say, nerve-tissue, instead of producing, is, when in action, constantly 

 concerned in maintaining a condition of things which diminishes muscular 

 irritability, and that not simply when it is engaged in the production of 

 motion. Hence muscular tissue, relieved from the operation or influence of 

 nerve-tissue, gradually acquires exalted contractile powers either in the pre- 

 sence or absence of the blood. 



3. That the blood, or the nutritional plasma derived therefrom, not only 

 furnishes the materials by which musciilar irritability is maintained, but is 

 likewise the determining cause of that polar arrangement of the muscular 

 molecules which maintains or restores the elongated or relaxed state. 



It is a well-obsei'ved fact in physiology, that after the death of animals the 

 irritability of the muscles frequently exhibits itself in an abnormal manner. 

 In the living animal or the amputated limb, the contractions which are in- 

 ducible by the application of stimuh, such as galvanism, pinching, or striking, 

 are of a pulsatory character ; that is to say, the contraction is limited in extent 

 and speedily gives place to relaxation ; but in the cases where the peculiarity 

 alluded to is present, the contractions following on such stimuli are more ex- 

 tensive and persistent, and simulate very perfectly contraction induced by 

 volition. The same pecuHar exalted susceptibility has also been witnessed in 

 man after death from certain forms of disease, more particularly in cholera 

 and yellow fever. 



Dr. Bennett Dowler, by experimenting upon amputated limbs, proved the 

 dependence of this phenomenon upon muscular irritability alone. It is as- 

 serted, not only that in some of these cases the movements can be excited by 

 mechanical stimulation, but that they not unfrequently occm- spontaneously, 

 and strongly resemble the actions of the living state. Carpenter quotes the 

 case of an Irishman, aged 28, in whom the following series of movements took 

 place spontaneously not long after the cessation of the respiration : — " First 

 the left hand was carried by a regular motion to the throat and then to the 

 crown of the head ; the right arm followed the same route on the right side ; 

 the left arm was then carried back to the thi-oat and from thence to the breast, 

 reversing all its original motions, and finally the right hand and arm did exactly 

 the same." This hyper- irritable condition of the muscular system attracted 

 the notice of Dr. Brown Sequard, and he found it to present itself more con- 

 stantly in young animals. This experience of Brown Sequard's is conform- 

 able with my own ; but I have also been fortunate enough to observe it in 

 cold-bloods with sufficient frequency to enable me to study it. It is well 

 known that in many particulars the young of warm-bloods are analogous to 

 the cold-bloods ; and one of these is the length of time that muscular irrita- 

 bility persists. 



