122 



ARON. 



Table VII. — Skin temperature — Continued. 



RUBNER. 



Boom temperature 



25°.6. 



26°.5. 



Individual 



N. 



R. 



Rbch. 



R. 





Angle of nose 



Eyelid.. 



31.0 

 32.0 

 31.0 

 33.0 



31.3 

 33.1 

 32.0 

 33.0 



33.1 

 33.8 

 33.1 



32.7 

 33.6 

 32.3 



Hand . . 



Skin 









I proceeded in different ways in order to study the influence of. the 

 radiation of the sun on the skin temperature. I placed a man in a 

 sunny place in such a way that half of his face and body were exposed 

 to the sun rays, the other side being in the shade, and the temperatures 

 of corresponding places of both sides of the body were taken. Another 

 arrangement was the following: The skin temperatures of several places 

 on the skin were taken in the shade, the spot where the highest tem- 

 perature of a certain region was found was marked by a very fine mark 

 and the subject then placed in the sun, in some experiments sitting, in 

 some lying on a cot. The temperature of the same marked places was 

 again determined at different intervals of time after exposure. In several 

 sets of observations I have studied a Filipino and a white man side 

 by side. 



The results of the insolation experiments are as follows: The naked 

 human skin if exposed to the rays of the sun is warmed very quickly 

 to about 36°. If one side is kept in the shade, the other exposed, the 

 difference in temperature on the two sides may amount to 3°. (See Table 

 VIII.) Above 36°, in a maximum 37°, the temperature of the skin no 

 longer increases; on- the contrary, if the exposure is continued, the 

 temperature falls. This fall is more or less coincident with the outbreak 

 of sweat, and the greater the secretion of sweat, the greater the fall in 

 the temperature of the skin. The fall in skin temperature is more 

 decided if the sweat secretion is increased by performing muscular work 

 in the hot sun. (See Table VIII.) 



