OF NATURAL HISTORY. rSy 



of its nerves. But, in general, difguft at particular foods is produ- 

 ced by furfeits, which injure the ftomach, and create, in that exqui- 

 fitely irritable vifcus, an infuperable antipathy to receive nourifli- 

 ment which formerly gave it fo much uneafinefs to digeft. 



Brute animals, efpecially thofe which feed upon herbage, and are 

 not liable to be corrupted by example or neceflity, diftinguifti taftes 

 with wonderful accuracy. By the application of the tongue, they 

 inftantly perceive whether any plant is falutary or noxious. To 

 enable them, amidft a tho.ufand plants, to make this difcrimination, 

 their nervous papillae, and their tongues, are proportionally much 

 larger than thofe of man. 



OF HEARING. 



THE fenfation of hearing is conveyed to the mind by undula- 

 tions of air ftriking the ear, an organ of a very delicate and complex 

 ftrudure. In man and quadrupeds, the external ears are large, and 

 provided with mufcles by which they can ere<3: and move them from 

 fide to fide, in order to catch the undulations produced in the air by 

 the vibrations of fonorous bodies, or to diftinguifli with greater ac- 

 curacy the fpecies of found, and the nature and fituation of the ani- 

 mal or objedl from which it proceeds. Though the human ears, 

 like thofe of quadrupeds, are furnifhed with mufcles, evidently in- 

 tended for fimilar movements, yet, I know not for what reafon, 

 there is not one man in a million who has the power of moving his 

 ears. When we liften to a feeble found, we are confcious of an 

 exertion ; but that exertion, and the motions produced by it, are 

 confined to the internal parts of the organ. 



The 



