PHYSICAL AND LITERARY. 279 



tory organs uninfluenced by the mind, con- 

 fiderably lefs than the weight of the at- 

 mofphere ; finc.e, if, after exfpiration, we 

 prevent the entry of the air by the glottis^ we 

 cannot dilate the thorax as in infpiration, tho* 

 there is ftill a good deal of rarefying air in the 

 lungs ? 



Do not the infpiratory organs, during 

 infpiration, overcome the refinance of the 

 expiratory organs, and likewife that fliare of 

 the preiTure of the atmofphere, which the 

 airi ruihing into the lungs, does not ba- 

 lance ? 



. Are not the ribs arched, and the fpaces 

 between them narrow, to prevent ill effedts 

 from that unbalanced part of the atmofphere 

 during infpiration ? 



Art. 



