FOOD. 



219 



temporarily, by the introduction of even non-alimentary substances into 

 this organ. It may, therefore, be said that the sensation of hunger is 

 caused both by a want in the system generally, and also by the condition 

 of the stomach itself, by which condition, of course, its own nerves are 

 more directly affected. 



The sensation of thirst, indicating the want of fluid, is referred to the 

 fauces, although, as in hunger, this is, in great part, only the local decla- 

 ration of a general condition. For thirst is relieved for only a very short 

 time by moistening the dry fauces; but may be relieved completely by the 

 introduction of liquids into the blood, either through the stomach, or by 

 injections into the blood-vessels, or by absorption from the surface of the 

 skin or the intestines. The sensation of thirst is perceived most naturally 

 whenever there is a disproportionately small quantity of water in the 

 blood: as well, therefore, when water has been abstracted from the blood, 

 as when saline or any solid matters have been abundantly added to' it. 

 And the cases of hunger and thirst are not the only ones in which the 

 mind derives, from certain organs, a peculiar predominant sensation of 

 some condition affecting the whole body. Thus, the sensation of the 

 "necessity of breathing/' is referred especially to the air-passages; but, 

 as Volkmann's experiments show, it depends on the condition of the 

 blood which circulates everywhere, and is felt even after the lungs of 

 animals are removed; for they continue, even then, to gasp and manifest 

 the sensation of want of breath. 



Starvation. The effects of total deprivation of food have been made 

 the subject of experiments on the lower animals, and have been but too 

 frequently illustrated in man. (1) One of the most notable effects of 

 starvation, as might be expected, is loss of weight; the loss being greatest 

 at first, as a rule, but afterward not varying very much, day by day, until 

 death ensues. Chossat found that the ultimate proportional loss was, in 

 different animals experimented on, almost exactly the same; death 

 occurring when the body had lost two-fifths (forty per cent.) of its original 

 weight. Different parts of the body lose weight in very different propor- 

 tions. The following results are taken, in round numbers, from the table 

 given by M. Chossat: 



Fat 



Blood . 



Spleen . 



Pancreas 



Liver . 



Heart . 



Intestines 



Muscles of locomotion 



Stomach 



Pharynx, ((Esophagus) 



Skin 



loses 93 per cent. 

 . 75 " 

 . 71 

 . 64 

 . 52 

 . 44 

 . 42 

 . 42 

 . 39 

 . 34 

 33 



