SUSPENDED ANIMATION. 2 29 



heart at length, ceases to act ; the cessation of its action 

 being also in great measure, probably, brought about, 4-thly, 

 by the imperfect supply of oxygenated blood to its muscular 

 tissue. 



In some experiments performed by a committee ap- 

 pointed by the Medico-Chirurgical Society to investigate 

 the subject of Suspended Animation, it was found that, in 

 the dog, during simple apncea, i.e., simple privation of air, 

 as by plugging the trachea, the average duration of the 

 respiratory movements after the animal had been deprived 

 of air, was 4 minutes 5 seconds; the extremes being 

 3 minutes 30 seconds, and 4 minutes 40 seconds. The 

 average duration of the heart's action, on the other hand, 

 was 7 minutes 1 1 seconds ; the extremes being 6 minutes 

 40 seconds, and 7 minutes 45 seconds. It would seem, 

 therefore, that on an average, the heart's action continues 

 for 3 minutes 15 seconds after the animal has ceased to 

 make respiratory efforts. A very similar relation was ob- 

 served in the rabbit. Recovery never took place after the 

 heart's action had ceased. 



The results obtained by the committee on the subject of 

 drowning were very remarkable, especially in this respect, 

 that whereas an animal may recover, after simple depriva- 

 tion of air for nearly four minutes, yet, after submersion in 

 water for I J- minutes, recovery seems to be impossible. 

 This remarkable difference was found to be due, not to the 

 mere submersion, nor directly to the struggles of the 

 animal, nor to depression of temperature, but to the two 

 facts, that in drowning, a free passage is allowed to air out 

 of the lungs, and a free entrance of water into them. In 

 proof of the correctness of this explanation it was found 

 that when two dogs of the same size, one, however, having 

 his windpipe plugged, the other not, were submerged at 

 the same moment, and taken out after being under water 

 for 2 minutes, the former recovered on removal of the plug, 

 the latter did not. It is probably to the entrance of water 



