NATURAL THEOLOGY. 175 



quently, the greatest strength and power of resistance 

 are wanted. 



Also, the quill part is a curiosity. It consists of 

 two sets of fibres, the one running lengthwise, which 

 are those we separate when we make a pen ; and 

 the others passing around the quill, like" the ferrules 

 upon a cane, or the hoops upon a barrel. The rings 

 secure the quill from being split. The hoops are 

 a security to the staves. Hence it is, we are obliged 

 to scrape a quill before we can get a split. We must 

 in fact unhoop the barrel. 



B. How many kinds of arts we have had exem- 

 plified in the living machine ! Here, it seems, we 

 have that of the cooper. — Speaking of the the cover- 

 ing of animals, is there any design, we can perceive, 

 in the difference of color ? 



A. It is found, that heat will not escape so easily 

 through a white surface. The colors of animals in 

 very cold countries are remarkably inclined to white ; — 

 and animals are apt to become of this color, when 

 removed to a high latitude. We can assign no other 

 reason for this, but a beneficient appointment of Provi- 

 dence, for the comfort of the animal. The natives of 

 hot countries, on the contrary, are more or less of a 

 dark complexion. 



B. But does not black absorb the heat, or, as is 

 commonly said, draw the sun ? and must it not there- 

 fore be an uncomfortable color, in those regions ? 



A. There are some recent experiments which 

 seem to shew that a black color will protect the skin 

 from the scorching effects of the sun's rays ; and it is 



