232 NATURAL THEOLOGY. 



VII. 



OP THE THORAX AND MECHANISM OF RESPIRATION. 



Our author might have made more use of the 

 thorax as affording proofs of his great argument. 

 We have here represented the spine, breast-bone, 

 and ribs, as the anatomist articulates them. Were 

 he to make a skeleton in this fashion, it would be 

 fragile in an extraordinary degree, compared with 

 the natural body ; and if the skeleton fell, it would 

 inevitably be broken. Let us see, then, what gives 

 protection to the bones in the natural body. The 

 celebrated John Hunter w^as much engaged in 

 showing by what means elasticity came in aid of 

 the muscular power, both in the textures circula- 

 ting the blood, and in those ministering to the play 

 of the lungs. We may observe how the same 

 principle conduces to the protection of the ribs as 

 well as assists their motion in respiration. 



The anterior part of the rib (/) which ekes out 

 the rib (F G) and joins it to the breast-bone, (C,) 

 is formed of elastic cartilaf^e ; and the rib having 

 a free articulation behind to the spine, it results 

 that each rib is possessed of elasticity. The ana- 

 tomist making no proper substitute for this in the 

 artificial skeleton, the bone breaks easily, like a 

 piece of china. We have another proof in the na« 



