COLOUR. 339 



quite, as hot as the surrounding air, evaporation will be 

 checked, except from the exposed parts, the temperature 

 of the skin will rise, and the cooling process of radiation 

 will be more or less stopped. In this case, any gain which 

 may be obtained in lessening the absorption of heat, by 

 wearing white, as persons do in hot countries, will be 

 a direct gain. During the summer months in tropical 

 latitudes, the hair on a horse's body will, usually, be so 



Photo hy] [M. H. H. 



Fig. 406. — Captain Woolnier's Indian country-bred, Minden. 



short and thin, that its presence will offer no impediment 

 to the action of the skin. Agreeably to the foregoing 

 observations, we find that black and brown horses stand 

 heat best ; and that white — especially if they have pink 

 skins — and grey animals sustain it comparatively badly. 

 I have frequently observed on hot days in tropical climates 

 that, other things being equal, grey horses sweated far 

 more readily and profusely than those of darker shades. 



22* 



