Mifcellanea Curiofa. 187 



fince exploded and condemned upon ample Con- 

 viction ; and 'tis a Point yet undetermined, whe- 

 ther any Air does mix with the Blood at all in the 

 Lungs, or not. 



But fuppofing, that fbme Air may infinuate 

 it (elf into the Pulmonary Vein, it can no other 

 way dilate the Heart than by an Effervefcence 

 in the Left Ventricle, which wou'd not dilate 

 the Right. But this Opinion is contradicted 

 by Autopjie, and too laborioufly confuted by 

 others, to be brought upon the Stage again 

 herer 



There remains therefore only the grofs Body of 

 the Atmofphere to be confidered, whis is undoub- 

 tedly the true Antagonitt to all thofe Mufcles, 

 which ferve for ordinary Infpiration, and the 

 Conftriction of the Heart. This will appear 

 more evidently, if we confider not only the 

 Power, but the Neceflity of its Action upon Ani- 

 mal Bodies, as well as the want of other fuffici- 

 ent Agents. 



The Heart is a Solitary Mufcle of very great 

 ftrength, and the Intercoflal Mufcles and Dia«* 

 phragm, which likewife have no Antdgonifts, are 

 a vaft additional Force, which mud be balanc'4 

 by the contrary Action of fome equivalent Power 

 or other. For, tho' the Action of the Intercoflal 

 Mufcles be voluntary, that does not exempt them 

 from the condition of all other Mufcles ferving 

 for voluntary motion, which wou'd be in a State 

 of perpetual Contraction, notwithftanding any 

 Influence of the Will, were it not for the Libra- 

 tion of Antagonift Mufcles. This Libration be- 

 tween other Mufcles, is anfwer'd by the Weight 

 of the incumbent Atmofyhere> which prefles upon 

 the Thorax and other parts of the Body. And, 



as 



