1873.] Irritability after Systemic Death. 341 



out mechanical injury there is a period in the process of cooling when 

 general muscular irritability may be made manifest. He demonstrates 

 this fact by the simple experiment of throwing a current of water heated 

 to 115° Fahr. over the arterial system of the recently dead animal. If 

 the surrounding temperature be high at the time of this experiment, the 

 operation should be performed within a few minutes after death ; but 

 if the temperature be below freezing-point, it may be dela}~ed for a long 

 period. In one experiment the author reproduced active muscular con- 

 traction in an animal that had lain dead and exposed to cold 6 degrees 

 below freezing-point for a period of three hours. In this case the 

 muscles generally remained irritable for seven minutes after the injection 

 of the heated water, while in the muscles of the limbs, by repeating the 

 injection at intervals, the irritability was maintained for two hours. 



The author drew a comparison between these experimental results and 

 the phenomena of muscular irritability that have been observed in the 

 human subject after death by cholera. A short description of the 

 muscular movements occurring sometimes after death from cholera was 

 introduced. The movements were not conscious, nor were they pro- 

 moted by electrical excitation ; but the flexors and extensors belonging to 

 each part in which there is movement are alternately contracted and re- 

 laxed as if from some internal influence. The same observations apply 

 to the phenomena of contraction and relaxation in the muscles of animals 

 that have been held in abeyance by cold and have been recalled into 

 action by the injection of heated fluids. 



The influence of cold in suspending without destroying muscular irrita- 

 bility was further evidenced by the experiment of subjecting some young 

 animals to death, by the process of drowning them in ice-cold water. It 

 was shown that in the kitten the muscular irritability may be restored to 

 the complete reestablishment of life after a period of two hours of apparent 

 s} r stemic death, although the muscles when the animal is first removed 

 from the water may give no response to the galvanic current. This 

 same continuance of irritability after apparent systemic death by drown- 

 ing in ice-cold water has been observed in the human subject, not in so 

 determinate, but in an approximated degree. An instance was adduced 

 in which a youth who had been deeply immersed for twelve minutes in ice- 

 cold water retained muscular irritability so perfectly that he recovered, 

 regained consciousness, and lived for a period of seven hours. 



Commenting on the method of irritability, the author showed that a 

 certain period of time is required before the irritability is raised from a 

 mere passive condition, in which it responds only to external stimuli, 

 into the condition necessary for independent active contractility. The 

 change of condition from the passive to the active state, when it occurs, is 

 so sudden as to seem instantaneous at first, then it is slowly repeated. 

 This rule holds good in respect to voluntary muscles and involuntary. It 

 is specially true in regard to the heart, which organ, the author states, 



vol. xxi. 2 r 



