256 Human Frame* 



sense. The organ of smelling is trft Nose 

 The cavity of the nose is divided into 

 two parts, we call the nostrils, by a parti- 

 tion, of which the upper part is bony, 

 and the lower cartilaginous. The upper 

 part of the cavity is covered with a thick 

 glandulous membrane, above which the 

 olfactory nerve is finely branched out anc 1 

 spread over the membrane of the spon- 

 gy bones of the nose, and other sinous 

 cavities of the nostrils. Whence the ex- 

 halations of odours entering the nostrils 

 make their impressions on the fibres of 

 the nerves, which by their communica- 

 tion with the brain, excite in the mine" 

 the smell or sensation of odours of eve- 

 ry kind. 



Smelling bodies seem perpetually td 

 send forth effluvia or steams, without 

 sensibly wasting at all. Thus a grain of 

 musk will send forth odoriferous parti- 

 cles for scores of years together, without 

 its being spent ; whereby one would con- 

 clude that these particles are very small ; 

 and yet it is plain, that they are much 

 grosser than the rays of light, which have 

 a free passage through glass ; and gros- 

 ser also than the magnetic effluvia, which 



