. ADAPTATION TO CLIMATE. 397 



developed in man. He ia less than any other being bound to any par- 

 ticular zone, and is further suited to the widest diffusion, because, con- 

 fined to no especial food, he is, in the fullest sense of the word, omniv- 

 orous. He is, not only by the organization of his body, but especially 

 by his mental power and his energetic will, fitted above all other 

 creatures to accommodate himself to the most various influences that 

 can affect him from without, and by continuous habitude to endure or 

 make bearable the strangest conditions. He can live at the extreme 

 limits at which organic life can exist, and can sustain a degree of cold 

 at which quicksilver freezes. Thus, three Russians lived for seven 

 years in Spitzbergen without suffering in health. Admiral Wrangell, 

 while in the Chuckchee country in 1820, experienced a cold of nearly 

 50° below zero, while his men were as lively and happy as if it had 

 been summer ; and Parry and Franklin withstood a still greater cold. 

 Man can also sustain an almost incredible degree of heat. The cele- 

 brated physician, Boerhaave, believed that no being breathing with 

 lungs could live in an atmosphere having as high a temperature as 

 that of the blood. According to this dictum, one ought to die at a tem- 

 perature of 100°, but Banks enjoyed good health on the Senegal when 

 the thermometer rose in his cabin to above 120° and 130°. Men live on 

 the southwest coasts of Africa, and in other hot regions, where the heat 

 of the sand under their feet reaches 140° or 150°. Men in deep min- 

 ing-shafts and under diving-bells are able to support an atmospheric 

 pressure of 30,000 kilogrammes as well as a pressure of only 8,000 

 kilogrammes on the highest mountains. Cassini thought that no ani- 

 mal could live at a greater height than 4,700 metres, or 15,000 feet ; 

 but there are several inhabited places situated at a still greater height, 

 as, for instance, Gartok, in the Himalayas. Alexander von Humboldt 

 ascended Chimborazo to a height of nearly 6,000 metres, or 19,286 

 feet, without suffering any harm. The pressure of the atmosphere is 

 so light at such elevations that, as Humboldt was assured, wild ani- 

 mals when driven up to them bleed at the mouth and nose. Only the 

 dog is able to follow man as far and as high as he can go ; but this 

 animal, too, loses his acute smell in Congo and Syria, and the power 

 of barking in Surinam and at great heights ; and the finer breeds of 

 dogs can not long endure the conditions of a height of more than 

 3,760 metres, or 12,500 feet, while there are towns in the Andes at as 

 great a height as 13,500 or 14,000 feet. 



But there are regions in which even man perishes, to whatever race 

 he may belong, and however well prepared he may be to resist their 

 deadly influence. Among such regions is the Gaboon valley, in which 

 even the negro is disabled. The inhabitants of that district are de- 

 cidedly weaker in constitution, and have greatly diminished reproduc- 

 tive powers, and the women are considerably in excess. There are simi-- 

 lar regions nearer the centers of civilization. The Tuscan Maremma 

 is famous for its deadly air, and the swamps of Corsica are of like 



