NATURAL THEOLOGY. 161 



perfect and connected whole. You may describe the 

 heart. 



A. The heart, with its connected machinery the 

 arteries and veins, is the immediate contrivance by 

 which the blood is distributed. It is as perfectly 

 artificial as any machine whatever for conducting or 

 forcing water. The arteries are the blood vessels 

 which convey the blood from the heart to every part 

 of the body. The veins are the vessels by which it 

 is collected and returned ; while the heart is the en- 

 gine which is continually throwing it out in one di- 

 rection and receiving it in another. 



T. How is all this performed ? 



A. The heart is a hollow muscle, divided on* 

 into several rooms, — and is made upon the principle 

 of a fire engine. 



T. You have mentioned a striking comparison. 

 We have found almost every kind of apparatus in the 

 human frame ; — but one would hardly have thought 

 of hearing of a fire engine. 



B. 1 believe it is not an imaginary resemblance, 

 however. 



T. By no means : there is a most extraordinary 

 similarity ; and to evince the wisdom of the Creator 

 more perfectly, and observe how exactly one of the 

 most ingenious productions of art has been anticipated 

 in the living structure, you may describe & fire engine. 



A. A fire engine requires, in the first place, to 

 have a room to recieve the water, which in the best 

 engines, is carried to it by a hose or leathern tube. 

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