328 TEE POPULAR SCIENCE MONTHLY 



If I were to add to this lecture a paragraph of practical hints, I 

 would say, first of all, keep your houses and offices cool, never above 

 and usually well below 70° F. Unfortunately here a difference between 

 men and women sometimes causes trouble. Woman possesses a per- 

 petual blanket of adipose tissue between her skin and her muscles, which 

 is usually less developed in man, and hence women can dress more 

 thinly than men, and are usually comfortable at a lower temperature. 

 I have seen more than one happy home in danger of wrecking from 

 this unfortunate difference. As a married man I am tempted to plead 

 for greater charity on the part of wives ; as a physiologist I realize that 

 a lower temperature is more healthful. Keep room air in motion. An 

 electric fan or a current of air from a window is a great aid in keeping 

 down one's bodily temperature, and preventing sleepiness and bodily 

 discomfort from stagnant air; with electric fans in use there would be 

 fewer naps in churches and lecture halls. Air in motion promotes effi- 

 ciency. Accustom yourselves to draughts, and especially big draughts. 

 A small blast of cold air directed against a small area of warm skin may 

 do harm, but the larger the current the more the harm gives way to 

 benefit. Air of constantly uniform temperature is monotonous and 

 debilitating. An occasional and considerable cooling, a flushing of the 

 room by a sudden large inrush of outside air is, like a cold bath, stimu- 

 lating. Do not be afraid of opening the windows of sleeping rooms at 

 night. The prejudice against night air, which arose naturally enough 

 from the belief in the existence of nocturnal disease-bearing miasms, in 

 the light of present knowledge is a foolish prejudice and must give way 

 to the rationalism of scientific fact. The increasing employment of 

 cool outdoor air both night and day as a therapeutic agent in the treat- 

 ment of disease is based on scientific principles and is justified by its 

 results. And, finally, the whole moral of the modern physiological doc- 

 trine of fresh air may be expressed tersely in the two short words, 

 keep cool. 



I have thus endeavored to present to you a fair picture of the pres- 

 ent attitude of science toward the problem of fresh air and its relation 

 to health. Such a consideration 'affords an unusually fruitful oppor- 

 tunity to witness the ways in which science progresses, forming hypoth- 

 eses, testing them and then retaining, rejecting or refining them, as the 

 evidence derived from observation and experiment warrants. Of the 

 subject before us there are still many gaps in our knowledge, and these 

 gaps must be filled. Present knowledge is never final, and our present 

 ideas of what constitutes fresh air may yet require revision. There has 

 recently been brought together in the City of New York under the in- 

 fluence of the Association for Improving the Condition of the Poor and 

 with governmental recognition a group of representative men of science 



