266 ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 



and the disease named pneumonia is the result of different causes which 

 need more distinct classification than they have yet received. 

 Dusty trades and smoky fogs favor the incidence of pneumonia. 



BRONCHITIS. 



Bronchitis, one of the most prevalent and fatal of all diseases in cold 

 and temperate climates, is often directly due to the effect of cold and of 

 a sudden fall of temperature. Although much less common and fatal 

 amoug people living in healthy conditions, it nevertheless often attacks 

 strong constitutions, even in the purest atmosphere. Fatigue predis- 

 poses. A great deal of preventable bronchitis results from imprudence 

 in clothing and in diet — for instance, alcoholic excess — but much also 

 from breathing dusty and smoky air. A smoky fog of some days' dura- 

 tion in cold weather in London causes a heavy mortality, while a fog in 

 the country has little effect. Much bronchitis results from weakness and 

 chill following illness and fatigue. Changes in the blood and accumu- 

 lation of waste products are apt to follow excessive exertion. The 

 importance of warm clothing and of breathing air free from smoke and 

 dust, especially the dust given off in the manufacture of hardware, pot- 

 tery, lead mining, etc., is great in the prevention of this disease. Close 

 rooms where gas is burned contribute largely to bronchial attacks, and 

 in general purity of air is one of the first conditions tending to immu- 

 nity. But cold and damp seem to be quite sufficient to produce bron- 

 chitis in some constitutions, and in young children and old people, 

 apart from anything like infection from outside. Indeed, it seems likely 

 that an excess of ozone, or else a cold, bracing air, often determines 

 an attack, and these qualities are beyond doubt sufficient greatly to 

 exacerbate symptoms resulting from a slight cold or chest weakness. 

 A soothing, soft, warm, damp air, on the contrary, quickly ameliorates 

 the condition of a sufferer from bronchitis, cold, or cough ; the extraor- 

 dinary power of a whiff of cool, fresh air to increase the malady, and 

 the ill effect of even a glass of cold water, seem to show that the bron- 

 chial tubes, capillaries, and air passages are in a highly sensitive state 

 and that temperature is a matter of extreme importance. Experimental 

 investigation of the temperature and condition of air most tending to 

 rapid recovery from bronchitis might disclose facts of importance in 

 the connection of inflammatory states with the atmosphere. It seems 

 not unlikely that an absence of ozone, deficiency of oxygen, and excess 

 of vapor of water, and of nitrogen or carbon dioxide, might prove 

 favorable. 



RHEUM AT LSM AND RHEUMATIC FEVER. 



Few diseases are more common or cause more suffering than rheu- 

 matism, acute or chronic. A great deal has still to be discovered 

 respecting its external causes. It prevails much more in some districts 

 than in others, and certainly in many cases the mischief is brought 

 into the human system through the air. Damp and cold in soil and air, 



