CLIMATE AND COMPLEXION. 5 



check which the presence of haze, mist, or cloud in the atmosphere 

 puts upon radiation. A humid temperate climate is also warmer than 

 others in the same latitude, for it owes its existence in every case to 

 breezes from warm seas. Breezes from cold seas can not produce a 

 true humid temperate climate, because when they strike the land in 

 summer they will be raised in temperature and rendered dry. 



In humid temperate climates, since the rays of the sun, falling 

 obliquely through a moisture-laden atmosphere, lose much of their 

 light and heat, a dark pigment is a disadvantage. The vapor-clogged 

 air tends to prevent perspiration, therefore a thin epidermis is desir- 

 able. The combination of a thin epidermis with a light pigment will 

 give a fair complexion. 



III. By a dry temperate climate I mean one occurring in a temper- 

 ate zone in which the atmosphere is usually dry. Countries in which 

 this climate prevails are distinguished from others in the same latitude 

 by the great range of the thermometer. Their summers are hot and 

 their winters cold. As a protection against the greater heat and bright- 

 ness of the sun, a darker pigment than that which serves the purpose 

 in humid temperate regions is necessary. To prevent the too rapid 

 withdrawal of the fluid contents of the capillaries by the dry air, a 

 thick cuticle is required. The combination of a thick cuticle with the 

 pigment suitable to the intensity of the sun's rays will produce vari- 

 ous shades of yellow and brown. 



IV. By a humid tropical climate I mean one occurring in or near 

 the torrid zone, in which there is no dry season. In such a climate 

 vegetation will be luxuriant all the year round, and man will live in 

 the shade of dense forests, in a steaming and enervating atmosphere, 

 whose temperature will be high, but will vary little. Though the 

 rays of the sun will descend vertically upon him, yet their power will 

 be diminished by the vapor contained in the air, and he will not need 

 so dark a pigment to protect him as the inhabitants of other tropical 

 regions. Add to this, that a thin epidermis will promote perspiration 

 which the moisture-laden atmosphere tends to check, and we come to 

 the conclusion that the natives of such countries will be distinguished 

 by comparatively fair complexions. 



V. On the contrary, in a rainless tropical climate, or in one with 

 a well-marked dry season, the rays of a vertical sun will continually, 

 or for considerable periods, descend in all their power, and the blackest 

 and densest pigment and the thickest scarf-skin will be needed. Be- 

 tween the tropics the nights are always long, and, in consequence, 

 when in the dry season there is little moisture in the air to check radi- 

 ation, the thermometer, as many African travelers have remarked, falls 

 very low before sunrise. To withstand the loss of heat at such times 

 a thick outer skin will be an advantage. Accordingly, in these cli- 

 mates, we find the blackest men and very thick skins. 



This theory of the relations between the climate and the skin is, I 



