204 ROYAL SOCIETY OF CANADA 



We have thus all the conditions favourable for a chronic catarrh, and 

 this chronic condition being established we get all the typical symptoms 

 of naso-pharyngeal catarrh, spreading often to the Eustachian tubes 

 communicating with the middle ear. When this chronic congestion of 

 the naso-pharynx continues fior an extended period in young children, 

 we often have the starting point of adenoid growths, a troublesome 

 affection and one which is very widespread throughout communities. 

 Continuing downward along the respiratory tract, the conditions result- 

 ing from the irritation, due to an excessively dry atmosphere, must be 

 noted with reference to the bronchial tubes, and the small air passages 

 in the lungs. Here again a congestion is the primar}^ result, and the 

 effects produced must be considered from a double point of view : 



First: On the normal healthy lungs and bronchi. 



Second : On diseased lungs and bronchi. 



To take the second series first will perhaps serve us better. When 

 considering the effect of an irritation due to dry air on a mucous mem- 

 brane already irritated or congested by some disease, e.g.. Tuberculosis, 

 Bronchitis, Pneumonia, etc.,nio one can deny for a moment the deleterious 

 results that necessarily follow from such an added irritation. This 

 point being conceded, some real benefit can be extended to people 

 suffering from these diseases, by removing or replacing a very dry at- 

 mosphere with one containing an optimum of moisture. 



As a matter of fact most people have witnessed the use of a 

 bronchitis kettle for patients suffering from acute bronchitis — this 

 homely but efficient device supplying a quantity of water vapour to the 

 atmosphere which is to be breathed by the patient; the immediate relief 

 in these cases is most striking. 



Reverting to the first series, viz. the effects produced by a dry at- 

 mosphere on healthy lungs and bronchi, no such absolute or incontro- 

 vertible proofs can be brought forward as in the second series, but some 

 strong points may be brought out by analogy. 



It is now-a-days quite an accepted fact that where you have the 

 mucous membranes lining the lungs and bronchi in a congested or irri- 

 tated state, the conditions are then favourable for the " grafting on " of 

 some disease, e.g., most marked of all, Tuberculosis. 



If other mechanical irritations besides that produced by dry air can 

 be the starting point or predispositions of some disease, why not that 

 produced by dry air? 



This argument is brought forward only as a strong probability, but 

 it must gain in strength when the results, to be narrated below, of the 

 action of air which is too dry on the healthy membranes lining the nose 

 and throat, are carefully considered and weighed. 



