January 6, 1921] 



NATURE 



603 



retaining power, even of the wet material. In 

 tropical climates there is particularly a great dis- 

 advantage in clothes which lessen evaporation. 

 Heat-stroke is due to excessive heat stagnation. 



In regard to indoor conditions, these should 

 approximate as near as possible to the outdoor 

 conditions of an ideal day. 



Successful ventilation not only prevents heat 

 stagnation of the body, but also keeps the tem- 

 perature such thai it stimulates the worker without 

 producing uncomfortable cooling of the body. 



In the British climate, of mist and cloud, radiant 

 heat is always preferable to convected heat, hence 

 the superiority of the open fire and the modern 

 gas-stove. Radiant heat makes up for the absence 

 of sunlight. Buildings should always, so far as 

 possible, be warmed in such a manner as to keep 

 he feet warm and the head cool. The judicious 

 ' mployment of fans to impart Air movement will 

 frequently make all the difference between good 

 and bad ventilation. Dr. Hill's kata-thermometers 

 prove of the greatest service in investigating the 

 ventilation conditions of any building, and it is 

 certain that they must be extensively employed in 

 future to ensure satisfactory conditions, particularly 

 in large buildings. 



The question of the bodily heat regulation in 

 the tropics is one of vital importance to the 

 colonising white man. F'"or years past there 

 has been discussion as to whether it is possible 

 for the white man to adapt himself efficiently to 

 tropical climates, or whether this can be done only 

 by pigmented races. Many authorities have in- 

 clined to the latter view. 



The effect of the tropics is largely due to the 

 action of the sun's visual rays, particularly those 

 if the blue end, which, if sufficiently powerful and 

 prolonged in action, have a lethal effect upon 

 ()rotopIasm. The ultra-violet rays are filtered out 

 by the horny layer of the epidermis. The scales 

 of the skin reflect diffusively many of the visual 

 rays, particularly when the skin is wet with sweat. 



The function of pigment is to absorb the visual 

 rays, thereby protecting the blood and living 

 tissues from dangerous effects. The pigmented 

 man can, therefore, have a thinner horny layer 

 to his skin, and lose heat well through flushed 

 blood-vessels, without risks of injurious effects 

 from ground glare and sky shine. The view 

 which attributes a higher heat-emissive power to 

 the skin of the negro is erroneous. Despite the 

 above advantages, however, pigment puts an extra 

 tax on the heat-regulating mechanism of the body, 

 since it has to get rid of the heat into which light 

 rays are converted. 



The great value of pigment is that it protects 

 man from sunburn, and enables him to go naked 

 and secure the full cooling power of the environ- 

 ment by losing heat by radiation, convection, and 

 evaporation. The white man wears clothes to pro- 

 tect himself from sunburn, and the ill-effects of 

 tropical climates are largely due to the wearing of 

 unsuitable clothing, frequently from custom or 

 from an idea of caste distinction. The white man 

 also usually indulges in an unsuitable diet, which 

 sets his heat production at too high a level. For 

 this reason it is imperative that the white man in 

 the tropics shall be suitably clothed and adjust his 

 diet to the climate, resting during the hot hours, 

 and taking exercise freely during the cool of the 

 day. 



The efficiency of the yellow races in hot climates 

 shows that climatic adaptation to the tropics does 

 not depend solely on pigmentation of the skin. 

 .\s shown above, such adaptation seems to depend 

 upon the correct correlation between the meta- 

 bolism and the heat-losing mechanism of the body. 

 Given proper sanitary measures against infectious 

 disease, much can be done to promote the effi- 

 ciency of the white race in hot climates by getting 

 rid of the stagnant moist environment produced 

 by clothes and houses. These in particular tell 

 at present against the health of while women. 



M. F. 



The Discovery of Fossil Remains of M 



By Prof. k. 



pKOI . I.K.K.NK DUBOIS, the discoverer of 

 i Pithecanthropus, has recently published* an 

 .i< count of fossil remains of man found in a deposit 

 Ml Java, which he regards as of Pleistocene age. 

 In 1890, the year before he made his first find of 

 the remains of Pithecanthropus at Trinil, Prof. 

 I )ulMiis was led to search for traces of ancient 

 man in the district of Wadjak, which lies some 

 sixty miles to the south-east of the site where 

 his more famous discovery was made. His atten- 

 tion had been directed to the Wadjak district by 

 the discovery there of a fossilised human skull in 

 i88<). Further excavations of the terrace-like 

 '■ "'sii in which the first skull had bceti found 

 • rl Prof. Dubois in possession of fragments of 



■ " Dc Proco.AnalralJKlM rai«i>l« Mantch van W«di>k (J**a) A ', 

 AkMtl. vmm H'tifmfck. tt AmiltrH^m AftftetiHr^ May ■«. igtix 



NO. 2671. VOL. lofSl 



an in Java, Australia, and South Africa. 



Keith, F.R.S. 



the jaws and cranium of a second individual, which 

 I were in the same state of mineralisation as the 

 skull which first came to light. 



Prof. Dubois has only now published a full 

 account of these discoveries, made thirty years 

 ago. He finds that the remains unearthed at 

 Wadjak indicate that Java was at one time in- 

 habited by a people very like the blacks of .\u%- 

 I tralia, but in some respects even more primitive 

 than they- The publication of an account of a 

 fossil human skull foimd at Talgai, Queensland, 

 by Dr. Stewart .\. .Smith* in i<)i8 has appar- 

 ' entlv induced Prof. Dulwis to reinvestigate the 

 fossil remains from Wadjak, and to compare them 

 with the ancient Talgai skull. Thus for the first 

 time it is possible for anthropologists to compare 



• Phil, TrAn«.. i9if, iKf. B, vol. ccviii. , p. iti 



