132 PRODUCTION OF IDEAS. SECT. XIV. 8. 



VIII. Of the Appetites of Hunger -, Thirft, Heat, Ex- 

 tenfion, the 'want of frejh Air^ animal Love, and 

 the Suckling of Children. 



HUNGER is mod probably perceived by thofe 

 numerous ramifications of nerves that are feen 

 about the upper opening of the ftomach ; and 

 thirft by the nerves about the fauces, and the top 

 of the gula. The ideas of thefe fenfes are few in 

 the generality of mankind, but are more nume- 

 rous in thofe, who by difeafe, or indulgence, de- 

 fire particular kinds of foods or liquids. 



A fenfe of heat has already been fpoken of, which 

 may with propriety be called an appetite, as we 

 painfully deGre it, when it is deficient in quan- 

 tity. j?v 



The fenfe of extenfion may be ranked amongft 

 thefe appetites, fince the deficiency of its- object 

 gives dif agreeable fenfation ; when this happens in 

 the arterial fyftem, it is called faintnefs, and feems 

 to bear fome analogy to hunger and to cold ; 

 which like it are attended with emptinefs of a 

 part of the vafcular fyftem. 



The fenfe of want of frefh air has not been at- 

 tended to, but is as diftinct as the others, and the 

 firft perhaps that we experience after our nativity ; 

 from the want of the object of this fenfe many dif- 

 eafes are produced, as the jail-fever, plague, and 

 other epidemic maladies. Animal love is another 

 appetite, which occurs later in life, and the fe- 

 males of lactiferous animals have another natural 

 inlet of pleafure or pain from the fuckling their 

 offspring. The want of which either owing to 

 the death of their progeny, or to the fafliion of 

 their country, has been fatal to many of the fex. 

 The males have alfo pectoral glands, which are fre- 

 quently turgid with a thin milk at their nativity, 

 and are furniihed with nipples, which erect on ti- 



< tillation 



