DISCUSSION. 



DISCUSSION ON THE PAPER, AN EXPERIMENT WITH ORANGE-RED 

 UNDERWEAR," BY DR. J. M. PHALEN. 



Dr. Aldo Castellani, professor of tropical medicine and lecturer on 

 dermatology, Ceylon Medical College, Colombo, delegate from the Govern- 

 ment of Ceylon. — Doctor Chalmers arid myself have made some experi- 

 mental researches on the subject in Ceylon. "We have compared the results 

 obtained by exposing some rabbits directly to the sun-rays and by pro- 

 tecting others by placing white, red, etc., cloths on the cages. Those 

 protected by red cloth, or by cloth, white outside and red inside, survived ' 

 the longest. We also had good result by using Doctor Sanborn's "solaro" 

 cloth. However, I frankly admit that experiments on man as made by 

 Doctor Phalen are of more practical importance than experiments on 

 rabitts as carried out by Doctor Chalmers and myself. 



Dr. W. P. Chamberlain, major, Medical Corps, U. S. Army, president 

 of the United States Army Board for the Study of Tropical Diseases as 

 They Occur in the Philippine Islands. — These experiments do not show 

 that khaki cloth is as protective as orange-red against the chemical rays 

 that affect the photographic plate. 



Dr. Victor 67. Heiser, Director of Health for the Philippine Islands, 

 professor of hygiene, Philippine Medical School, Manila, P. I. — The 

 data given in this paper are indeed interesting. As I understand it, 

 these experiments were carried out with soldiers who wore khaki outer 

 clothing and controls wearing the same clothing. Furthermore, if I 

 undertand correctly, the author states that he has observed individuals 

 who have been in the Tropics for six years or more and who wore 

 khaki clothing continuously, and that in such persons the protected 

 skin showed no pigmentation, from which he inferred that the tropical 

 light was effectively excluded by khaki. If this is the cause, it would 

 seem that in order to draw correct deductions, it would have been 

 better to make these experiments with soldiers who wore white outer 

 clothing and orange-red underwear and with controls who wore white 

 outer clothing and white underwear, or that one regiment should have 

 been dressed entirely in white and compared with a regiment that was 

 dressed in khaki. 



56D 



