NATURAL THEOLOGY. 169 



breathing ;— through the mouth, and by the nostrils. 

 But for the latter, we could not breathe without diffi- 

 culty, in taking our food. The infant would find it 

 impossible. 



COVERING OF ANIMALS. 



T. You have now taken a general survey of the 

 internal structure. You may close with a brief ac- 

 count of the admirable covering with which the 

 whole is invested. 



A. The skin is a protection from the air, which 

 we know from experience, would occasion insup- 

 portable suffering, if it were immediately in contact 

 with the flesh. For this and other purposes, there is 

 a three-fold provision : there are three skins. The 

 first, called the epidermis, or scarf skin, possesses 

 no feeling, and covers the body, like a glove. It is 

 this skin which is raised by a blister. The next is 

 the seat of the color ; — in Africans black, — in the 

 European, white, Sic. This is called the retc 

 cosum. Last of all, is the true skin ; the anatomical 

 expression is cutis, which in Latin signifies skin. 



T. Another use of the skin is to prevent 

 body from , being overheated, and to preserve * an 

 equal temperature in the system. 



B. This must be some extraordinary contrivance. 

 A. There are innumerable little orifices, termed 



pores, in every part of the skin, though invisible ro 



