1873.] 



Irritability after Systemic Death. 



343 



during permanent contraction, was described from experiments bearing 

 on the relation of temperature to the muscular contraction of different 

 animals — frogs, pigeons, and rabbits. It was shown that a relative rise 

 in temperature in each class, a rise averaging 12 degrees in Fahr. scale, 

 from the natural temperature of the animal is efficient for producing 

 permanent rigidity, the cause of the ultimate rigidity being coagulation 

 of the coagulable muscular fluid. 



The effect of electrical excitation is in the same direction, but is varied 

 according to the mode in which the excitation is performed. Discharge 

 from the Levden jar produces contraction, which is permanent or inter- 

 mittent in accordance with the mass of the muscle and the intensity of 

 the discharge. This fact was elucidated by reference to a series of 

 experiments with a Leyden battery, placed in cascade, and the effect 

 produced by the discharge from 96 feet of surface upon animals of 

 different sizes and weights, from sheep down to pigeons, as well as on 

 sections of the bodies of the same animals immediately after death. The 

 experimental facts demonstrated that with an efficient discharge the 

 whole muscular system of a small animal could be fixed instantly in the 

 rigidity of death, and that the precise position of the animal at the period 

 immediately preceding death was retained with such perfection, so 

 sudden was the change, that nothing but physical examination by the 

 hand could bring to the mind the fact that the animal had passed from 

 life into death. 



But the same shock passed through a sheep weighing 54 pounds pro- 

 duced only a temporary contraction of muscle, and required several 

 repetitions before the rigidity was rendered permanent. 



By employing discharges of lower tension it was found that muscles, or 

 special tracts of muscles, in the same animal, immediately after its death, 

 could be made rigid quickly or slowly by variation of the intensity of 

 the discharge. 



The effect of the intermittent electro-magnetic current was next 

 brought forward, and was shown to resemble closely that of the simple 

 electrical discharge from the Le}^den phial. Intensified it induces in- 

 stant and permanent contraction ; and if it be repeated, even with but 

 sufficient force as to call forth feeble contraction, it destroys the irrita- 

 bility, cceteris paribus, more quickly than if the muscle had been left at rest. 



Parenthetically, the lecturer dwelt here on the common practice after 

 sudden death of endeavouring to excite the action of the enfeebled heart 

 by passing through it an electrical current. Some practitioners, said the 

 author, have gone so far as to introduce a needle into the heart itself, 

 and to make the needle act as one of the conductors from a battery. 

 Such experimentalists, before they undertake this operation on the 

 human subject, should at least observe the effect of the agency they are 

 employing on the exposed heart of an inferior animal recently and 

 suddenly killed by drowning or by a narcotic vapour. They would learn 



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