"PNEUMATIC SPACES" 533 



Hence the snuffer, or snuff-taker, when he wants to 

 cogitate deeply, helps himself to his much-loved pinch. 



In further connection with the subject of snuff-taking, 

 as conducing to the unloading of the cerebro-spinal cavity 

 of its surplus fluid contents, and thus aiding in the work of 

 the senses and intellect, it might be asked if it might not 

 thus indirectly aid in the excretion of such morbid products 

 as the materies morbi of rheumatism, and whether, there- 

 fore, snuffers are less afflicted with that and kindred 

 diseases than are non-snuffers ? 



Snuffers may be said to induce artificial sweating from 

 the olfactory mucous membrane. 



As bearing on the anatomy and distribution of the 

 olfactory nerve fibres.in and on the dog's nose, and a large 

 number of the lower animals of that and other species, it 

 would be most interesting, and it might be useful to know, 

 whether the membrane or skin reflected over the point of 

 the nose contained terminal fibrils of the olfactory nerve, 

 and, consequently, the sense of smell, or whether its range 

 of sensory power is purely tactile. 



We might almost be warranted, however, in inferring 

 from what we observe in the dog, and a very large number 

 of the mammalia, that the structure in question is per- 

 meated by terminal fibres of the olfactory nerve, or other 

 nerve elements capable of appreciating certain qualities of 

 matter, odoriferous or otherwise, whereby they are enabled 

 to select their food with greater ease and exactitude, and 

 even to perceive with less effort distant objects, provided 

 these objects are shedding odorous particles. 



This covering, or nasal cap, seems to be a mucous, or 

 modified mucous, membrane, continuous with that of the 

 nasal passages, and being generally moist, it may be, from 

 that continuity, it presents a surface to which floating 

 particles of matter readily adhere, and from which nervous 

 molecular impressions are conveyed to the sensorium. 



This surface, therefore, becomes a part, and may be 

 called the " advanced guard," of the proper sense of smell 

 in its relationship to environment. 



A somewhat similar office appears to be served by the 

 lips in connection with the sense of taste. 



