206 OF FOOD ANU HUNGER. 



331. The necessity of obeying these stimuli is greater 

 or less according to age, constitution, and especially 

 according to habit, and nothing can therefore be posi- 

 tively affirmed respecting its urgency ; but thus much 

 is certain, that an healthy adult, in whom all the calls 

 of nature are felt in their usual force,* cannot abstain 

 from food a whole day without great prostration of 

 strength, nor scarcely beyond eight days without danger 

 to life. (C). 



332. Although thirst is a violent desire, drink ap- 

 pears not very necessary to life and health ; for many 

 warm blooded animals, — mice, quails, parrots, &c. do 

 not drink at all; and some individuals of the human 

 species have lived in perfect health and strength with- 

 out tasting liquids.f 



333. It has been disputed whether our food, by which 

 we satisfy these stimuli, is derived more advantageously 

 and the more consistently with nature from the animal 

 or from the vegetable kingdom. + 



334. Some contend that man is herbivorous, from the 

 snape of his teeth,§ the length of his intestines,|| the dif- 

 ference between the structure of the small and large 

 intestines, and from the cells of the colon. Rousseau 

 ingeniously urges the circumstance that woman is na- 



* Consuk, among innumerable writers on long fasting, James Bartbol. Bec- 

 carius, Cmmrnta* instituti Jiononiens, T. ii. p. 1. and Flor. J. Voltelen, 

 Memorab. apositiee septennis hist. LB. 1777. 8vo. 



f G. Baker, Med. Transact '. published by the Coll. of Physicians m Loudon* 

 vol. ii. p. 267> sq. » I 



X J. W. Nvergnnnl, Vergleichende .luatomic mid Physiologic der Vcr- 

 daumnrswerkzeuge dcr Saugethierc und Vojrel. Berlin. 1806. p. 244. 



§ Gussendi, Letter to J. Bnpt. v. Hclmont Opera. Florence. 1727. fol. 

 T. vi. p. 17. Al. Monro, Scnr. Sumy on Comparative .J/tulomy. p. 17. 



Ii J. Wall!*, Philos. Trans. No. 26i). 



