1 86 Mijce llama Curiofa. 



towards the Deprejfwn of them, and Co balance the 

 Account. But the chief ufe of thefe is in violent 

 Refpiration : In ordinary Refpiration their (hare 

 is fmall. 



Such a real Power (which may in the leaft be 

 fufpe&ed of any fhare in this Action) is hard, 

 perhaps impoflible to be found in the Machine of 

 any Animal Body ; and yet without fbme fuch 

 Antagonift, it is as impoflible the Circulation of 

 the Blood fhould be maintain'd. All the En- 

 gines yet difcover'd within the Body, confpire to- 

 wards the Conftri&ion of the Heart, which is the 

 State of Quiefcence, to which it naturally tends. 

 Yet we find it alternately in a State of Violence, 

 that is, of Dilatation j and this upon neceflity, 

 becaufe upon this Alternation depends all Animal 

 Life. 



Some fufficient Caufe External muft there- 

 fore be found, to produce this great Phtfnome* 

 von , which Caufe muft be either in the Air, 

 or Atmofphere, bccaufe we have no conftant and 

 immediate Commerce with any other Medi- 

 ums* 



Some great Phyficians obferving this, and that 

 deprw'd by whatfbever means of Communication 

 with the external Air, we became inftantly ex- 

 tincl:, have imagin'd, that in the A& of Infpira- 

 tion certain purer parts of the Air, mixed with the 

 Blood in the Lungs, and was convey 'd with it to 

 the Heart, where itnourifh'd a fort of Vital Flame, 

 which was the Caufe of this reciprocal Alftus of 

 the Heart. Others not quite fo grofs, rejecting 

 an AHual Flame, have fancied, that thefe fine 

 Parts of Air mixing with the Blood in the Ventri- 

 cles of the Heart, produc'd an Effervescence which 

 dilated it. But thefe Fancies have been long 



fince 



