NOTES ON CLIMATE. 7 



There is a marked difference between the inhabitants of the 

 arid tracts and those of the moister countries. The latter are 

 more rotund in form and ruddy in complexion, than the 

 dwellers in the arid districts, who are spare in figure, of less 

 average weight, and swarthy in complexion. The reason of 

 this is evident when we consider that an arid atmosphere 

 induces a rapid abstraction of the moisture from every pore 

 on the surface of the body and from every air cell of the lungs. 

 Scientific observations have shown that no matter how dry the 

 air inhaled into the lungs may be, that when it is expired it 

 is saturated with moisture. At each respiration the lungs are 

 estimated to inhale and exhale 25 cubic inches of air, and in 

 twenty-four hours 375 cubic feet. This 375 cubic feet of air 

 requires from one half to two pounds of moisture to saturate 

 it. In addition to this there is a larger evaporation from the 

 surface of the body. Dr. Oscar Leow, while in the service of 

 the United States in the geographical survey of the Colorado 

 Desert, made accurate observations of the amount evaporated 

 from the body in that hot and arid region. He found that 

 4 2-9 pounds of moisture was abstracted in a state of vapor 

 during the twelve day hours, and when engaged in heavy work 

 the amount was nearly doubled; that from 6 to 10 pounds, or 

 from f of a gallon to 1& gallons was abstracted from the sur- 

 face of the body and the lungs every twenty-four hours. The 

 pulse was increased in frequency and the body reduced in 

 weight. Of the results he writes, "It is evident that by drink- 

 ing large quantities of water the blood must acquire a high 

 degree of dilution; hence all the juices, those of digestion, 

 including the pancreatic and gastric, must be more diluted 

 than usual, and the power of digestion weakened; that but a 

 limited amount of food was digested, no matter how much 

 was eaten, and there was a decrease of muscular power." A 

 great amount of humidity combined with cold induces inflam- 

 matory diseases; if combined with heat it relaxes the system 

 and predisposes to fevers and to diseases of the mucus mem- 

 branes of the stomach and bowels. Prof. James PI. Bennett 

 states that "moisture with the thermometer between 55 and 6o 



