MiJceUanea Curiofa. 1 8 1 



to fb narrow a compafi, and that he had given us 

 an explication at large of fo abftrufe and fo im- 

 portant a Phenomenon : Becaufe the Specific!^ Gra- 

 vity of the Bipod feems to me a caufe by no 

 means alone adequate to the effecT:, which it is 

 here fuppos'd to produce. 



For, if the Blood acts only as a weight by 

 meer gravitation, then that part of it only 

 which descends from the Parts above the 

 Heart can be employ'd in that Action. This 

 at the largeft computation can't amount to 

 Five pound weight, and mult, according to 

 the computation of Borellus, force a Machine, 

 that is able to overcome a refiftance of 135*, 

 000 /. I leave every Man to deduct what he 

 fliall upon examination find reafbnably to be 

 deducted, and yet {hall reft fecure, that it is 

 not to be effected in the leaft with fb fmall a 

 Weight. 



But neither does the Refluent Blood gravi- 

 tate in any fuch proportion, as I have here 

 aflign'd. For to make a true eftimate of its 

 Gravitation, we mujt confider the Circumftan- 

 ces of the liquor fuppos'd to gravitate ; in 

 which it very much refembles Water inclos'd 

 in a recurve Tube, of which, if the length of 

 the two Legs be equal, it may be fufpended 

 in the Air full of Water, with the Extremi- 

 ties downwards, without lofing a drop, al- 

 though the Diameter of thofe Legs fhould be ve- 

 ry unequal. The Cafe of the Arteries and 

 Veins is pretty near a parallel to a Tube, fb 

 fill'd and inverted. For, if the Arteries and 

 Veins be continued Tubes, (as by the Micro- 

 fcope they are made to appear) then (up- 

 poling their contents to have no other deter mi- 

 N 3 nation 



