CARE OF THE THROAT AND EAR. 793 



process. Summarized in a few words, it is simply to warm, moisten, 

 and clean the air which we inhale. 



The healthy nostrils are anatomically and physiologically so 

 formed that when the current of air passes through them it will have 

 been freed of its mechanical impurities, warmed to within a few de- 

 grees of the temperature of the body, and moistened to saturation. 

 This has been experimentally demonstrated. 



The opening of the passage of the ear into the throat has several 

 objects, the most important being ventilation and the adjustment of 

 the atmospheric equilibrium. This passage leads outward until it 

 enters the cavity of the middle ear, which is closed by the drum on 

 the outside, thus separating it from the external canal of the ear. We 

 know that atmospheric pressure varies at different times and in dif- 

 ferent altitudes. It is much less, for instance, at the top of a moun- 

 tain than at the seaside. The opening into the throat allows the air 

 to enter, and adjusts the atmospheric pressure within the ear to these 

 various external conditions. Those of you who have ascended Look- 

 out Mountain by means of the incline cable car may have noticed the 

 adjustment taking place by a peculiar click when different altitudes 

 were reached. 



So intimately are the nose, throat, and ear connected that it is 

 unusual to find one affected to any considerable extent without the 

 others being involved. While the rules of hygiene in general are 

 applicable to the nose, throat, and ear, there are certain special condi- 

 tions which deserve consideration. One of the most common causes 

 of injurious effects to the nose, throat, and ear is the so-called " cold." 

 The cold in this connection is, of course, understood to be simply the 

 cause, the condition itself being a peculiar inflammation of the parts 

 concerned. As cold is so frequently a cause of diseases of these parts, 

 it would be well to consider under what circumstances it develops and 

 the best mode of prevention. 



I have often noticed that persons who suffer most frequently and 

 severely from colds usually insist that they exercise the greatest care 

 to avoid exposure. They have dressed in the warmest clothing, 

 wrapped the neck in the heaviest mufflers, remained in the closest 

 rooms, and avoided every draught, and yet they continually " take 

 cold." The street urchin, on the other hand, with only two or three 

 garments and without shoes, and who lives out of doors, suffers less 

 frequently from this affection. 



" Colds " have truly been called a product of modern civilization. 

 The trouble was rare among the aborigines and is more common 

 among the cultured than among the laboring classes. If we make a 

 plant an exotic, we must keep it in the conservatory, and even here it is 

 not free from danger. On the other hand, if we wish to harden it and 



