352 PHYSIOLOGY CHAP. 



The same writer made another set of investigations in order 

 to find the amount of heat emitted by the inner cutaneous surface 

 of the thigh ; for these experiments he made use of the Winternitz 

 air-calorimeter. He found that on an average the temperature 

 of 60 c.c. of air is raised T4 C. in ten minutes by the white 

 skin of a healthy person, the temperature of whose body is 

 37'2 C., whereas it is raised 1'7 C. by the brown skin of natives 

 under exactly the same conditions; so that the skin of the 

 native emits a greater amount of heat than does that of the 

 European, and we therefore see that in hot climates Europeans 

 are at a considerable disadvantage as compared with natives. 



According to Glogner, another point in which Europeans 

 living in the tropics differ from natives is the course of the curve 

 of the temperature of the body in the twenty-four hours ; in the 

 Javanese this curve shows oscillations much like those of the 

 curve of the temperature of the body of Europeans living in 

 Europe (see results of Jiirgensen and Liebermeister, page 67 of this 

 volume), but the curve of the temperature of Europeans living 

 in the tropics takes a different course. We note that during 

 the early morning hours it rises earlier and more rapidly; 

 during the day it remains relatively stationary, so that between 

 7 and 9 A.M. the temperature of the body is about half a degree 

 higher than in Europe at the same time. It is not however 

 accurate to say as is stated in various books on the subject 

 that the temperature of the body in the tropics is on an average 

 half a degree higher than in Europe, since later in the day, when 

 the temperature rises in Europe, it remains stationary in the 

 tropics, as we have already pointed out. 



Glogner further remarks that in the tropics the tissues of 

 men and animals, European and native alike, contain less fat, 

 and therefore the inhabitants of such climates show less 

 tendency to grow fat than those of cold or temperate climates. 

 He thinks that this tendency may be explained as one result of 

 acclimatisation that is to say, as an adaptation to the special 

 need in hot climates of eliminating the greatest possible amount 

 of heat from the body, which end is attained by reducing the 

 thickness of ,the subcutaneous adipose layers. This process is 

 the exact opposite of that which is observed in organisms living 

 in cold climates. 



All explorers agree that the inhabitants of cold climates, 

 such as the Eskimos, can consume, and indeed require, an enormous 

 amount of fat-containing food. The observations made by the 

 famous explorer Nordenskjold during the winter spent by him 

 and the crew of the Vega in Bering Straits show that Europeans 

 living in these severe climates also need a richer diet if they are 

 to remain in good health. The men's rations contained- a larger 

 quantity of proteins and fat than would be required by a well-fed 



