PROCKEDIXGS OF SECTION P. 599 



time by the once white inhabitants, after they have become colored 

 in the course of generations, being subdued as an inferior race by a 

 fresh influx of whites from temperate latitudes. 



The first competent writer on the subject I will cite in favor of 

 colored labor in the tropics and sub-tropics is Major Charles Woodruff, 

 a surgeon in the United States Army. He has conducted elaborate 

 investigations in the Philippines and in the Southern States of America 

 bordering on the heat-belt, and has published the results of his labors 

 in an able book on the effects of light on white men in the regions 

 referred to. His contention is that the disorders which, sooner or later, 

 afflict our race in tropical and sub-tropical latitudes are caused, not by 

 excess of heat, but by excess of light. It is well known that those 

 actinic rays which are of a short wave length — the violet, indigo, and 

 ultra-violet rays — are highly penetrative, and produce what amounts 

 to a chemical action on the human body. Referring to the chemical 

 phenomena produced by those waves, Sir William Crookes, a former 

 president of the British Association for the Advancement of Science, 

 says, " We have actually touched the borderland where matter and 

 force seem to merge into one another." Dr. Woodruff holds that 

 tropical and sub-tropical exhaustion, loss of memory, tropical and sub- 

 tropical asepsia, nem'asthenia. several obscure skin diseases, and some 

 curious fevers are due to the action of the actinic rays on a body which 

 has not sufficient pigmentation to resist them. The same wTiter found 

 in the Philippines that a large proportion of Americans from northern 

 cities in the United States, who become residents in those islands, 

 and who at first praise the climate, are themselves numbered amongst 

 its victims within two years after landing. In proof of the marked 

 sensitiveness of the white man's constitution when transferred from 

 the temperate zone to even the fringe of the sub-tropics, Dr. Woodruff 

 shows that the Scandinavians who have emigrated to the northern 

 States of America become liable to alarming disorders and nervous 

 irritability, and die out in the third generation. The main line of his 

 argument — which seems impregnable— is that the world is divided 

 into color-zones, and that each climate is exactly suited hy natural 

 law to the particular human racial tyj)e evolved under its influence, but 

 cannot be adjusted to any other. He denies that in a permanent change 

 of residence from a temperate to a tropical or sub-tropical zone, accli- 

 matisation is possible, except after a long period, and then only by the 

 very rare " survival of the fittest." Nor, in this case, is the " fittest " 

 the healthiest or the most adventurous, but the darkest man. 



Ten years ago, von Schmaedel, in a paper read before the Munich 

 Anthropological Society, stated that the black man's skin has, in the 

 process of evolution, developed the dark tint as nature's protection 

 against the disease-bearing actinic rays. Animals, too, unless pro- 

 vided with thick pelts or black skins, cannot resist the short actinic 

 rays, and avoid the light. According to the same authority, a blonde 

 skin is adapted to a northern climate, where the sunlight is pale and 

 where many of the short rays are absorbed in the tropical sun. Even 

 brunette races, in sub-tropical climates, exclude as much light as 



