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 tht, 

 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, &c. This is called the rete mu- 

 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 the 

 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 



jpores, in every part of the skin, though invisible to 



F 



