XII, B. 1 Shaklee: Experimental Acclimatization 21 



I hope to make a more detailed report of these experiments 

 in a subsequent paper. 



SUMMARY 



1. The normal temperature of the Philippine monkey probably 

 varies between 37.5° and 39.5° C. 



2. Unacclimatized Philippine monkeys (genus Pithecus) ex- 

 posed to the sun in Manila live or die of heat stroke in the course 

 of from several minutes to several hours, depending upon the 

 conditions. 



3. The conditions making for a rapid death are: A hot 

 sun; proximity of a large, hot surface, such as the ground or a 

 roof ; high relative humidity of the atmosphere ; and a low wind 

 velocity. 



4. The death under these conditions is due to an accumulation 

 of heat in the body. 



5. The lack of any one of the above conditions may prevent 

 death. 



6. The effect of the sun's rays alone on this monkey is com- 

 paratively slight. 



7. These monkeys on a suitable diet become acclimatized to 

 the conditions mentioned, if exposure to the conditions is gradual. 



8. A small dose of atropin will cause the death of an accli- 

 matized monkey by stopping the perspiration. 



9. The acclimatization consists in an increase in the sensitive- 

 ness of the nervous mechanism which regulates the body temper- 

 ature. The increase in sensitiveness produces an increase in the 

 rate of perspiration under the conditions named above, producing 

 in this way what may be termed an immunity. 



10. This immunity is readily lost if the monkeys are kept in 

 the shade. 



11. Some forms of sickness diminish the powers of resistance 

 to the above-mentioned conditions. 



12. Some toxins produced in the intestine lower this resistance. 



13. Rabbits showed no increase in resistance when treated 

 in the manner used to acclimatize monkeys. 



14. Healthy white men may be readily acclimatized to the 

 conditions named, that is, to the tropical climate at its worst. 



15. The amount of sweating necessary to keep the body tem- 

 perature of a healthy white man from rising above normal is not 

 excessive, even when the man is doing considerable physical 

 work in the midday sun in such a tropical climate as that which 

 obtains at Manila, provided the man has been sufficiently long 



