TROPICAL CLIMATE 13 



In tropical countries, the nights are almost universally cool 

 and comfortable. The range of temperature, as already stated, 

 is never great, the total annual range rarely being greater than 

 30. Moreover, there are no extremes of temperature to be 

 endured. It is possible in all tropical countries to live prac- 

 tically out-of-doors, at least with doors and windows con- 

 stantly open. The question of fresh air and ventilation is, 

 therefore, solved automatically. The same weight of clothes 

 can be worn the year round, thus avoiding the necessity for 

 the bodily adjustments rendered inevitable by the rigors of the 

 northern climates. 



Notwithstanding the fact that many of the tropical cities 

 have been rendered even more sanitary from the viewpoint of 

 specific diseases than are northern cities, and notwithstanding 

 the fact that tropical cities possess almost none of the ordi- 

 nary discomforts of climatic conditions and changes, it still 

 remains doubtful whether the Tropics are well adapted for the 

 permanent residence of the white man. It has not been ade- 

 quately explained, and perhaps may never be fully explained, 

 why the delightfully uniform and comfortable climate of the 

 Tropics lowers the vitality and vigor of a considerable per- 

 centage of the white men who go to live in the Tropics. While 

 it may not be possible to explain this, it is nevertheless a fact. 

 Some persons are affected by a general lassitude and depres- 

 sion within a few days after landing in a tropical city, others 

 are not affected at all, or only after a long residence without 

 any trips in the meantime to colder climates. There is no 

 way of predicting who will be injuriously affected and who 

 not by going to the Tropics. The depressing influence of cli- 

 mate may be shown most strongly in a vigorous, healthy in- 

 dividual and may not be manifestec it all in invalids or 

 weakly persons who go to the Tropics for a visit or for per- 

 manent residence. 



It is a common and apparently well founded belief that 

 most white races of the Tropics should pay a visit to some 



