( 12 17 ) 
II. A Vifcoufje concerning fome Infuencecf Rcfpira- 
tion GM the Motion of the Heart, hitherto 
ohferved. J. Drake, M. D. F. R. S. 
T Ho divers accurate Treatifes of the Hearty arid its aSi- 
on, have been written by Learned Men of feveral 
Nations, efpecially by two of our own Country ^ the Great 
Dr Harvey, to whofe happy Sagacity this Nation owes the 
Glory of tiie Invention of the Circulation of the Blood 
and the incomparable Dr Lower ^ to whom we are behold- 
ing for a compleat difplay of the Mechanical Strud^Hre of 
the Hearty and a raoft ingenious Rationale of its Aftion. 
Yet there remain feveral doubts and difficulties about it (in 
my opinion) not fufficiently accounted fior, towards there- 
folving fome of which I fhall offer what my own thoughts 
have foggefted to me, and leave it to the confideration of 
the Reader. 
The Learned Dr Lomr ( whofe accurate piece on this 
Argument will infure his Reputation fo long as Phyfical 
knowledge (hall laft in efteem) has fo well accounted for 
the Sjijiole, or Contraftion of the Heart from tliQ Mechamr 
cal Scrufture of it, that he feems almoft to have exhaufted 
the fubjeft, and had he been ai happy in difcovering the 
true caufe of the Diajiole, he had left little room for the 
Induftry and Sagacity of others about this Vifcus. • 
But having judicioufly and folidly explain d the SjiJloL\ 
he contents himfelf to afcribe the Diajiole to a motion of 
^ Rejlimion, which account gives me no fatisfaftion : Be- 
caufe the S)>Jlole being the proper, and (as himfelf confeffes) 
the only motion of the Heart, a ftate of Cojitra&ion feems 
to be the natural ftate, and confequently v/ithout external 
violence, it fliou'd have no Diajiole at all. 
Cccccccc This 
