OF NATURAL HISTORY. 175 



The feelings thus excited inftantly produce a change in the fenfitive 

 organs by which they are occafioned. If the objedt be poflefTed of 

 difagreeable qualities, averfion is the neceflary confequence. But, 

 if beauty and utility are perceived in the obje£t, pleafant emotions 

 fpring up in the mind, which naturally induce a fimilar tone or dif- 

 pofition in the organs fuited for the enjoyment of thefe qualities. 



When examining or enjoying any object, it is natural to inquire, 

 what are the changes produced in the nervous papillae, or organs of 

 fenfation ? If an obje£t poflefled of agreeable feelings is perceived, 

 the nervous papillae inftantly extend themfelves, and, from a ftate 

 of flaccidity, become comparatively rigid like briftles. This exten- 

 fion of the papillae is not conjedlural : It is founded on anatomical 

 obfervation, and, in fome cafes, may be feen and felt by perfons of 

 acute and difcerning fenfations. When a man in the dark inclines to 

 examine any fubftance, in order to difcover its figure, or other qua- 

 lities, he perceives a kind of rigidity at the tips of his fingers. If 

 the fingers are kept long in this ftate, the rigidity of the nervous 

 papillae will give him a kind of pain or anxiety, which it is impof- 

 fible to defcribe. The caufe of this pain is an over-diftenfion of 

 the papillae. If a fmall infedl creeps on a man's hand, when the 

 papillae are flaccid, its movements are not perceived : But, if he hap- 

 pens to diredt his eye to the animal, he immediately extends his pa- 

 pillae, and feels diftindtly all its motions. If a body be prefent, 

 which, in the common ftate of the nerves, has fcarcely any fenfible 

 odour, by extending the papillae of the noftrils, an agreeable, difa- 

 greeable, or indifferent fmell will be perceived. When two perfons 

 are whifpering, and we wifh to know what is faid, we ftretch the 

 papillae, and the other organs of hearing, which are exceedingly 

 complex. If a found is too low for making an impreflion on the 

 papillae in their natural ftate of relaxation, we are apt to overftretch 

 the organ, which produces a painful or irkfome feeling. When we 



examine 



"V 



