THE PHILIPPINE 



Journal of Science 



B. Tropical Medicine 



Vol. XII JANUARY, 1917 No. 1 



EXPERIMENTAL ACCLIMATIZATION TO THE TROPICAL SUN ^ 



By Alfred Ogle Shakleb 



(From the Laboratory of Pharmacology, College of Medicine and Surgery, 

 University of the Philippines, Manila) 



INTRODUCTION 



After a series of exposures of monkeys to the sun, Aron * 

 concluded that the monkey was more susceptible to the action 

 of the sun than any other animal with which he was acquainted, 

 "including even the white man," and that monkeys exposed to 

 the sun in a, garden or on a roof in Manila die within seventy 

 or eighty minutes, even though exposed in the early forenoon, 

 in the coolest months of the year. 



If this be true, the monkey ought to be an especially favor- 

 able subject for a study of acclimatization. I began such a 

 study in October, 1911. 



During the course of the experiments four objects were kept 

 in view: (1) To see if the monkey gradually exposed to the sun 

 would undergo a change which would enable it to live in the 

 sun throughout a hot day; (2) if this change should take place, 

 to learn its nature; (3) to determine the relative importance of 

 the various meteorological factors which may combine to in- 

 fluence acclimatization; (4) to learn in how far extraneous 

 factors, such as work, excitement, clothing, drugs, diet, and 

 disease, may influence the course of events. 



The monkeys used in this study were of the kind commonly 

 obtainable in Manila. They are of two sizes and may be of 

 two species. Probably both belong to the genus Pithecus.^ 



' Received for publication September 29, 1916. Read before the Philip- 

 pine Islands Medical Association, November, 1912. 



' This Journal, Sec. B (1911), 6, 110, 130. 



' For the scientific names of Philippine monkeys, see Hollister, This 

 Journal, Sec. D (1912), 7, 37; and Proc. U. S. Nat. Mus. (1914), 46, 328. 



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