Hi 



NOSK 



with the perpentliculor plate of the ethmoid, and 

 with the vuiiirr, forms a complete partition between 

 tin- right and left nasal fos*r. It is tin- lower 

 Intoral, termed by some writci-. tin- alar cartilage, 

 which by its flexibility ami curved shape forms 

 the dilatable chamber jilst itliin the nostril. The 

 nasal cartilages are capable of lieing slightly moved, 

 and the nostrils of being dilated or contracted by 

 various small muscles. 



The nasal fosMr, which constitute tlie internal 

 part of the none, are lofty and of considerable 

 depth. They open in front by the im.-niU, and 

 lo'tiind they terminate by a vertical slit on either 

 side in the upper part of the pharynx, aliove the 

 soft palate, and near the orifices of the Eustachion 

 tubes, leading to the tympanic cavity of the ear. 



The mucous membrane lining the nose and its 

 cavities is c&\\&\ pituitary (Lat. jiiliiitii, 'rheum'), 

 from the nature of its secretion ; or Schneider/an, 

 from Schneider, the first un.-auiii.-i who showed 

 that the secretion proceeded from the mucous 

 membrane, and not, as was previously imagined, 

 from the brain ; it is continuous with the skin of 

 the face at the nostrils, with the mucous covering 

 of the eve through the lachrymal duct (see EVE), 

 and with that of the pharynx and middle ear 

 posteriorly. This membrane varies in its structure 

 in different parts of the organ. On the septum 

 and s|M>ngv bones iHiunding the direct passage from 

 the nostrils to the throat the lining membrane 

 contains ample and capacious suhmucous plexuses 

 of both arteries and veins, of which the latter are 

 by far the more large and tortuous. These plex- 

 uses, lying as they do in a region exposed more 

 than any other to external cooling influences, 

 appear to be designed to promote the warmth of 

 the part, and to elevate the temperature of the air 

 on its passage to the lungs. They also serve to 

 explain the tendency to hemorrhage from the nose 

 in cases of general or local plethora. In this, the 

 respiratory part of the nose, the mucous membrane 



9 



fig. 2. Distribution of the Olfactory Nerve on the 

 Septum of the Now : 



1, fronUl uliiun; J, nal bone; 4, uphdinliUI inn* of left tide; 

 7. posterior opening of the If ft nostril ; 8, opening of Eiinto- 

 enlui tube; , wctlon of unit palate; 10. Kctlon of hard 

 palate, a. olfactory nerre ; 6, IU thre root* ; c, It.i tmlli : 

 '. nasal branch from the ophthalmic division of the fifth 

 n*nre ; t, nuo-paUllne nerre ; g. h, IU branches ; i, the 

 aeptum of the noae. 



in lined by ciliated epithelium. In the npper third 

 of the none which, ns the proper seat of the sense 

 of smell, may lie termed the >-/f'irtitry retfion the 

 mucous membrane in verv thick and coloured by H 

 brown pigment. The olfactory nerve, or nerve of 



smell, terminates in the olfactory mucous mem- 

 hntnc. It passes into the nasal cavity in several 

 small branches; these ramify in the soft mm-oiis 

 membrane ( lig. 2), and end in tiny varicose fibres 

 vhifli terminate in elongated epithelial cells pio- 

 jecting into the free surface of the nose. These 

 cells the olfactory cells which in some nninmls 

 are provided with little hairs, are affected by 

 (Nbinius particles, and the excitement thus set up 

 travels to the bruin by t he branches of the olfactory 

 nerve. In order to smell a substance it must be 

 in the form of va]nmr. A scent such as Eau de 

 Cologne when poured into the nostril is odourless ; 

 its little particles must be disengaged, and be 

 carried freely by the atmosphere into the nasal 

 cavity before we are affected bv its odour. So 

 sensitive is the nose, however, that odorous par- 

 ticles of inconceivable smallness are capable of 

 producing ]>owerful sensations. AVhcn we remem- 

 ber that a (rrain of musk will scent the air in its 

 neigfabaoiboad for years, and that this can only be 

 by the continual loss of panicles of its substance, 

 these particles must lie infinitely minute. Still 

 more wonderful is the development of the sense of 

 smell in many of the lower animals. A hare posses 

 rapidly over the ground and the scent will under 

 favourable circumstances remain for hours, and lie 

 sufficiently strong to enable the well-trained harrier 

 to follow it with unerring accuracy. In savage 

 tribes the sense of smell is vastlv more acute than 

 among civilised nations ; nevertheless by practice 

 it is possible for any one to cultivate this sense to 

 a very considerable extent. A\ ell-authenticated 

 cases are recorded of persons obliged by the loss of 

 the other senses to train this, the only one left 

 for their use, to such a degree of acutencss that 

 they have been able to recognise both objects and 

 persons by the sense of smell alone. 



Most persons imagine that we are largely be- 

 holden to ' taste ' for our gustatory pleasures. In 

 reality our sense of taste only enables us to dis- 

 tinguish sweet from sour or bitter, ami all the 

 flavour of the food or wine is smelt. Close the 

 nose and shut the eyes, and one cannot distinguish 

 port from sherry, a raw potato from an apple, 

 or lieef from mutton. 



Until recent years it was impossible to connect 

 the quality of a smell with the kintl of substance 

 that produced it. In hearing and sight the char- 

 acter of the vibrations of air or ether determines 

 the kind of sensation. The sound peculiar to the 

 violin or piano depends entirely on the character 

 of the sound vibrations given out by them. The 

 rose appears red because it reflects to the eye vibra- 

 tions which are chiefly characterised by their big 

 oscillations. The writer of this article has l>een 

 able to estahli-h a similar relationship lietwecn the 

 character of a smell and the character of the vibra- 

 tions as-ociatcd with odorous panicles. He finds, 

 in studying the : odours of elements aud their com- 

 pounds, that ill the 'Groups' of MendeleeH' (see 

 ATOMIC TIIKIIIIV, Vol. I. p. 652) the odours are 

 similar or vary with the atomic weight of the 

 element. Exactly similar properties in respect 

 io the production of colour sensations have been 

 observed by Carnelly. 



HIM IBB <IK THE NOSTRILS. Acute inflamma- 

 tion of the nasal mucous membrane haslicen already 

 described under the title of Catarrh (<i.v.); the 

 conditions which cause an offensive smell from the 

 nostril- are discussed in the article Oz^CNA ; and 

 1'olypus is a separate article. 



//. iiinrrliiii/f j'l-nin ilif \tutrilt, or Ejnstaxis (Gr., 

 'a dropping'), is by far the commonest form of 

 bleeding from a mucous membrane. It may lie 

 produced by direct injury, as by a blow on the 

 nose, or a scratch in the interior of the nostrils; 

 and by other local conditions, as ulcerations or 



