282 ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 



01 effects. Invigoration immediately follows a change from southern 

 England to the Alps, the Scotch Highlands, Norway, or the open sea; 

 a change for the worse, and loss of vigor overtakes natives of the north 

 of England or of Scotland who fix their abode in the Thames Valley 

 or near cities in the south. On the other hand, English crews may 

 winter in the Arctic regions, where temperature is 60 degrees below 

 what they are accustomed to, and diet coarse and unvarying; yet they 

 maintain perfect health. Food untainted and moderate in quantity 

 and abstinence from alcohol probably have much to do with health 

 maintenance in any climate. 



Temperature falls about 1° F. for every 270 feet altitude on the aver- 

 age. 1 Other conditions being equal, a place at 6,000 feet high has a 

 temperature fully 20° lower than the plain at the sea level. 



Generally, the range of temperature increases from the equator 

 toward the poles, from the coast toward the interior, and from moun- 

 tains in the tropics to mountains in northern countries. Humidity is 

 less at high levels, but relative humidity may be greater than at low 

 levels, and saturation may prevail for long periods. In Europe the 

 level of maximum rainfall is about 3,000 to 4,000 feet ; in the tropics, 

 also, the lesser mountain ranges have more rain than the highest, and 

 the maximum rainfall is about 6,000 feet. Mountain valleys are less 

 healthy than high plateaus. 



The " vital" or lung capacity diminishes from about 266 to 246 cubic 

 inches in the ascent from sea level to 2,000 feet, and the pulse beats 

 faster by fifteen to twenty in the minute. At 2,000 feet the pressure of 

 air on the chest is reduced by over 200 pounds. Since vital capacity is 

 also diminished by high temperature, the hill station can not equal in 

 this respect the temperate climate, but there is reason to believe that 

 the lung capacity increases in course of time so as to be fully equal to 

 its value at the low level. Evaporation from the skin and lungs 

 increase, and digestion and sleep are generally good. 



Strength is naturally greater in hill people. Life is hard, and the 

 weaker members perish; the pure air invigorates; the changes of tem- 

 perature refresh; good water is plentiful; the exertion of climbing and 

 the deep breathing expand the chest and increase the lung capacity; 

 the food is wholesome and notiu excess; activity and alertness are gen- 

 erally expected. On the other hand, in high mountain valleys malaria 

 is often found, also goitre, asthma, ophthalmia, inflammation of the 

 lungs, and diseases of the kidneys. Dysentery, acute bronchial catarrh, 

 typhus, albuminaria, and diabetes are rare; also the many zymotic and 

 other diseases more or less dependent on aggregation. 



In a period of thirty-four years the mortality of the Dutch-Indian 

 army was, on low ground, 5.27 per cent, on high ground, 3.66 per cent. 



1 The decrease would be less thau this — about 1 degree for each 400 feet, up to 1,000 

 feet. 



