6 



The Philippine Journal of Science 



1917 



Table II shows that the temperature of the monkey did not 

 rise above 40.8° on seven hours' exposure to the sun. This was 

 rather surprising in view of Aron's statement, and is all the 

 more noteworthy in view of the fact that on this day the monkey, 

 being still wild, struggled hard every time the temperature was 

 taken. On comparing the conditions at 10.25 in the forenoon 

 on November 29 with the conditions at 3.40 in the afternoon on 

 November 28, it is seen that the air temperatures were the same 

 on the two occasions, while the body temperature was 1.5° higher 

 in the sun than in the shade. This difference might be taken 

 for a measure of the effect of the sun's rays, if we did not know 

 that the monkey's temperature depends also upon the air hu- 

 midity, wind velocity, and individual resistance, factors ap- 

 parently overlooked by Aron in the statements cited. 



Weather data for these two days are given in Table III in a 

 form convenient for comparison. A study of the table will give 

 an idea of the action of the sun's rays alone. 



Table III. — Action of the sun's rays alone on monkey i-. 



Exposure. 



Date. 



Time. 



Body 

 temper- 

 ature. 



Time. 



Weather. 



Air 



temper- 

 ature. 



Black- 

 bulb 



read- 

 ing. 



Wind. 

 Meters 

 per sec- 

 ond. 



Humid- 

 ity. 



Sun 



Nov. 29 

 Nov. 28 



10.25 

 3.40 



°C. 



40.8 



39.3 



a. m. 

 10.00 



p. m. 

 3.00 

 4.00 



°C. 

 28.8 



30.0 

 29.6 



51.7 

 shade 



2.0 

 1.0 



56 



66 

 59 



Shade 





shade 1 0.0 











When we compare the air temperatures, winds, and humidities 

 of these two periods of observation, we find that, when the mon- 

 key was in the sun, the air temperature and humidity were less 

 and the wind was greater than when it was in the shade. Each 

 of these factors — the lower air temperature, the lower humidity, 

 and the stronger wind — would tend to produce a lower temper- 

 ature in the monkey. Since this was the first exposure to heat 

 in the sun, the power of resistance of the monkey to the sun 

 and heat was probably about the same as on the day previous 

 in the shade. The sun's rays, therefore, are the only factor that 

 would tend to raise the temperature of the monkey above that 

 of the previous day when the monkey was in the shade. There- 



