The subject has, unfortunately, to be considered largely from the standpoint of hypothesis and theory, as at present the facts do not admit of absolute proof. Personally, as a physician without numerous hospital cases to study or a physiologic laboratory to experiment in, I find it impossible to prove the truth of the theories I may entertain in this matter. Though my opportunities for observing these phenomena have been comparatively few at any one time, they have extended over some twenty-eight years of practice in Colorado, and, therefore, have the value of single spies, though they can not have the weight of battalions.
In rhinologic practice in Colorado one is struck with the fact that patients arriving from sea level often complain of nasal symptoms of which they had not been conscious at home. The reasons for this undoubted fact appear to me as follows: In the first