558 



DIGESTION. 



In some experiments on inanition undertaken by M. Chossat, 1 on 

 pigeons and turtle doves, the following general phenomena were ob- 

 served. Commonly, the animal remained calm during the first half or 

 two-thirds of the period. It then became more or less agitated, and 

 this state continued as long as the temperature remained elevated. On 

 the last day of life, however, the restlessness ceased, and gave place to 

 stupor. When set at liberty, it sometimes looked round with astonish- 

 ment, without attempting to fly, and at times closed its eyes, as if in a 

 state of sleep. Gradually, the extremities became cold, and the limbs 

 so weak as to be no longer able to sustain it in the standing posture. 

 It fell over on one side, and remained in any position in which it might 

 be placed, without attempting to move. Respiration became slower 

 and slower; the general weakness increased, and the insensibility became 

 more profound; the pupils dilated; and life became extinct, at times 

 in a calm and tranquil manner; at others, after convulsive actions, pro- 

 ducing opisthotonic rigidity of the body. 



He endeavoured to discover the effect of age in modifying the con- 

 tinuance of life during inanition, but was unable to ascertain the rela- 

 tive ages of the turtle doves, the subjects of his experiments; he 

 endeavoured, however, to form some estimate although, obviously, a 

 fallacious one from their relative weights, classing them as "young," 

 "middle-aged," or "adult," according as their weights were beneath 

 120 grammes, from 120 to 160, or above 160. The following table is 

 interesting, however, by showing the duration of life, and the loss of 

 substance during inanition, in animals of different weights. 



The entire absolute loss, and the proportionate loss, were much 

 greater in the heavier animals; the daily loss was by much the most 

 rapid in the lightest; and it is probable, that this was owing to the 

 more rapid waste which takes place in the young. 



The sensation of hunger resembles every other sensation in the mode 

 in which it is accomplished. There must be impression, conduction, 

 and perception. That the encephalon is the organ of the last part of 

 the process is proved by all the arguments used in the case of the 

 internal sensations in general. Without its intervention in this, as in 

 every other case, no sensation can be accomplished. The stomach is 

 the organ in which the impression is effected; and by means of the 

 nerves this impression is conveyed to the spinal marrow and encepha- 

 lon. The eighth pair or pneumogastric nerves have generally been 



1 Recherches Experimentales sur 1'Inanition, Paris, 1843; noticed in Brit, and For. Med. 

 Rev., April, 1844, p. 347. 



