In a very small proportion of cases certain kinds of dust and vapors con tinuously inhaled in connection with the occupation or habits are a sufficient exciting cause of a form of chronic rhinitis.
Pathology.—The habit of constantly taking cold is now generally believed by rhinologists to depend -upon anomalies of the septum, such as deviations, spurs, and crests; and in the case of the young to post-nasal adenoids as well. The great improvement which follows the removal of all these obstructing and irritating conditions is a sufficient proof to fix the responsibility of causation in these cases. There is a special dependence of the phenomenon of intumescence upon these deformities which shows that they con tribute largely to that turgescence of the mucosa and consequent obstruction of the 110Se which constitutes a large part of the symptomatology of rhinitis.
[.A. chronic catarrhal affection in a per fectly formed nose, without septal anom alies and minus the phenomenon of habitual intumescence Nl ould represent a simple chronic rbinitis and is admittedly of rare occurrence. Since certain au thors, like :MacDonald, attach especial significance to the shape of the nose in connection with intumescence, claiming, as they do, that the narrow, or Hebraic, type of nose especially allo,Ns obstruction from a slight degree of turgescence, it is evident that we must rate this narrow ness of nose as a factor in the same class with septal anomalies. The high-arched palate has also bcen claimed as a remote factor in the production of chronic rhinitis by narrowing the vertical di ameter of the nasal fossils and 1,1'119 pro clueing distortion of the septum. lint it
must not be forgotten that the high arched palate and the secondary &via tion of the septum arc both usually this result of long existing post. nasal ade noids, which also produce chronic rhi nitis by preventing post nasal drain age and interfering with the nasal cir Naturally the implication of the BIZ!. and shape of the naRal fossie involves the question of heredity and racial tend eneies in the causation of the digense.
...le tt tt t t? it tv °fort] Its .
a.t it: It fad tt hit 11 way 1,t, eNtilaineti t gnat. r frt. gut iwy of ,a.ptal • In wt t't ktzt—qt. E C. 11.R.E.] 1,:tt d 111 ItHlg-z;tailding rI.A.Itis are eitikr diffuse or r II. and it the failure to the purport of this distinc •,,,, v . lias led to much of the whieh the patholog.y of t r.. ninitis is involved. In the r, t t nrse of events any prolonged it azIon of a mucous membrane n tt,sarily be attended with a cer am' unt of thickening and indura ticn. with atrophy of some of the glandu lar cltintnts. But there is nothing to -w that this last process even attains a 11:gli degree in the nose, and to con frund it with atrophic rhinitis is, for I roam- reasons, unjustifiable.
In conclusion, then, the mucosa of the nasal fosste as a whole undergoes the chang.es which occur in chronic inflarn r,.ations of other inucos, but they are tiot of high degree and are completely overshadowed by certain circumscribed changes known as "hypertrophies," the prisence of which 0-ivez rise to the din t ; .al variety known as "hypertrophic rhinitis."