

STUDY X. 8$ 



This, too, is very remarkable, and of confe- 

 quential importance to the ufe which Nature 

 makes of thefe colours, to the North, and to the 

 South; namely, that in all countries, the whiteft 

 part of the body of an animal is the belly, becaufe 

 more heat is wanted there for promoting digeftion, 

 and carrying on the other animal functions : and, 

 on the contrary, the head is nniverfally moft 

 ftrongly coloured, efpecially in thofe of hot coun- 

 tries, becaufe, in the animal economy, that part 

 (lands moft in need of being kept cool. 



It cannot be maintained, that the bellies of ani- 

 mals preferve their whitenefs, becaufe that part of 

 the body is fheltered from the Sun ; and that their 

 heads affume ftrong colouring, from being more 

 expofed to his influence. It might appear, from 

 reafons of analogy, that the natural efFeft of light 

 ought to be, to inveft with it's luftre all the ob- 

 jects which it touches ; and that, conformably to 

 this, the foil, the vegetables, and the animals of 

 the Torrid Zone ought to be white ; and that 

 darknefs, on the contrary, acting for feveral months 

 together on the Poles, ought to clothe every ob- 

 ject, within thofe regions, in robes of mourning. 

 But Nature fubjects not herfelf to mechanical 

 Laws. Whatever may be the phyfical effect: of 

 the prefence of the Sun, or of his abfence, (he has 

 contrived, toward the North, toimpofe very black 



g 3 fpots 



