THE 



PHYSIOLOGICAL ANATOMY 



AND 



PHYSIOLOGY OF MAN. 



CHAPTER XVI. 



OF SMELL. CAVITIES OF THE NOSE. STRUCTURE OF THE NASAL 



MUCOUS MEMBRANE. OLFACTORY REGION. NERVES OF THE NOSE. 



CONDITIONS OF SMELL. 



THIS sense, designed to acquaint us with the odorous qualities of 

 particles suspended or dissolved in the atmosphere, is seated in a 

 portion of the nasal mucous membrane to which the air has access 

 during ordinary breathing, and it may fairly be regarded as ap- 

 pended to the respiratory organ, much as the sense of taste has 

 been seen to pertain to the digestive apparatus. But though it 

 may serve to protect the lungs from the inhalation of deleterious 

 gases, its principal use appears to be that of seconding the impres- 

 sions of taste in conveying intelligence of the properties of food ; 

 for it almost invariably happens, that food possessing a decided 

 flavour has likewise a not less characteristic smell. 



Unlike the organs of touch and taste, that in which smell resides 

 has no capacity of movement in relation to its ordinary stimuli; a 

 deficiency quite supplied by the expansion of the chest in breathing, 

 which carries the stream of odorous particles over the sentient 

 surface. 



The nose consists, 1, of two chief cavities or nasal fossce, sepa- 

 rated from one another by a vertical, bony, and cartilaginous sep- 

 tum, and each partially subdivided, by the spongy or turbinated 

 bones, projecting from the outer wall, into three passages or mea- 

 tuses: and, 2, of subordinate chambers, cells, or sinuses, of irregular 

 size, hollowed principally in the ethmoid, sphenoid, frontal, and su- 



* VOL. 11. B 



