TOL. XLIII.] PHILOSOPHICAL TRANSACTIONS. 6l 



ingly chills the air brought by the winds over them ; and of the nature of the 

 soil, which variously retains the heat, particularly the sandy; which, in Africa, 

 Arabia, and generally where such sandy deserts are found, make the heat of the 

 summers incredible to those who have not felt them, as the learned Dr. Halley 

 has remarked. Whence it will appear, that the heat or influence of the sun is 

 not always the same in the same latitudes, as those imagine who start this objec- 

 tion to this proposition; but that in Africa, where the people are black, the soil 

 is as intemperately hot as the climate, occasioned by the scorching heat of its 

 sands. This heat of the soil must much increase the heat of the sun, and its 

 power on the body ; and if the sun is the cause of blackness, must make the 

 people blacker in such places than any where else; which we see to be true of 

 the negroes in Africa, who are much blacker than the Indians of Asia or Ame- 

 rica, who live in the same climate, but inhabit more temperate countries. This 

 power of the sun will be much increased in such sandy soils. 



2. By the scarcity, if not entire absence, of large, spreading, succulent plants; 

 which afford, in other moist and more fertile soils in hot countries, agreeable 

 cooling shades, or a moist cool atmosphere, from their exhalations, which take 

 off much of the scorching heat of the sun. 



3. The want of water must much increase the heat of the body, if not of the 

 sun ; and conspires to the same effects as the more immediate heat of the sun it- 

 self. This is well known to be the case in Africa, from the many caravans that 

 perish for want of water in travelling through its midland parts : besides, it rains 

 $o seldom in many places of Africa, as to make it generally believed formerly, 

 that it never rained there at all ; which must much more exsiccate the body, and 

 parch the skin more powerfully, in those sandy regions, where no rain ever falls, 

 but at a certain season or two in the year, than in more temperate regions, though 

 in the same latitude. 



4. The ways of living in many hot countries, particularly in Africa, very much 

 contribute to increase the influence of the sun on the body, or to thicken and 

 harden the skin, on which its blackness depends. These customs are — 



1. The custom of going naked among most of the nations of Africa, especially 

 those that are black, both in former times and at present. 2. Living not only 

 without cloaths, but also without houses, in a very barbarous and rude manner, 

 little better than the wild beasts. 3. The custom of wandering up and down in these 

 sandy deserts, in the scorching heat of the sun, stark naked, with no house or 

 cool shade to retire to, nor water to refresh themselves with, or cool their bodies 

 in. 4. The custom of most people in hot countries of anointing their bodies 

 with some greasy and unctuous epithems, to defend their skins from the scorch- 

 ing heat of the sun, will be found likewise to increase the darkness of their 

 colours. 



