284 NATURAL THEOLOGY. 



XIII. 



OF HUNGER AND THIRST. 



For very sufficient reasons, we have preferred 

 taking the illustrations of design from the mechan- 

 ical structure of the body. We may nov^ intro- 

 duce some instances from the living properties, the 

 propensities and appetites. 



Hunger and thirst are in truth senses, although 

 the seat or organ is not easily ascertained. The 

 w^ants, and desires, and pain accompanying them 

 resemble no other sensations. Like the senses, 

 they are given us as monitors and safeguards, at 

 the same time that, like them, they are sources of 

 gratification. 



Hunger is defined to be a peculiar sensation ex- 

 perienced in the stomach from a deficiency of food. 

 Such a definition does not greatly differ from the 

 notions of those who referred the sense of hunger 

 to the mechanical action of the surfaces of the 

 stomach upon each other, or to a threatening of 

 chemical action of the gastric juice on the stomach 

 itself. But an empty stomach does not cause hun- 

 ger. On the contrary, the time when the meal has 

 passed the stomach, is the best suited for exercise, 

 and when there is the greatest alacrity of spirits. 

 The beast of prey feeds at long intervals ; the 



