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Hemm YeldXdiur^ & fanguine a Venk influente rurfus difiendi* 
fur 5 a nullo entm cordis motu^ nifi tenfionem fuam remit- 
tente, & ah irraente fanguine Diaftole ejus libratis adeo viri- 
bus fuccedit. 
I have tranfcribed the entire Paragraph, becaufe it con- 
tains his whole FIjpothefs of the Diajhlc^ and all the notice 
that he takes of it thro his whole Work- But how flender fo- 
ever this may prove, it is the moft fubflantial that I have 
any where met with, except a late one of Mr Cowper.v^hkh is 
properly an improvement of this, and fhall be confidered in 
the fequel. 
But, if Contraftion be the loleAftion of thefe Fibres fas 
this Great Man confeiTes it to be) and as indeed it is of all 
MnfcuUr Fibres, I wonder hov/ lo ja.dicioiis a Writer came 
to flip into fuch an abfurdity, as to call their Diftenfion 
( vulgarly but improperly called RelaxationJ a Motion of 
Re(litution, For from the Nature of tliofe Fibres, and their 
difpofition in the Strufture of the Heart,, the Natural State 
of the Heart appears manifeftly to be Tonical^ and its Dila- 
tation a State of Violence 3 and confequently the Con- 
ftriftion is the true motion of RefiHution^ and the State to 
which it will fpontaneoujlj return, when the Force is taken 
off, which is the work of the Intercojid Mufcles and D/V 
phragm. 
Thus we are left ftiil to feek for the true caufe of the 
Diafiole, v/hich feems to me to be the main and moft diffi- 
cult Phmiomemn^ relating to the Heart and the Circulation 
of the Blood. But in MvCor^pers ingenious hstrodtiBion to 
h\s Anatomy ofHtimm Bodies, I find the Share which Dr 
Lomr hints the Blood to have in that Aftion, further pro- 
fecuted, and improvM into the main Inftrument of the Di 
latation of the Heart, wherein I agree entirely with him. 
But as to the manner, and reafons of its being fo very iii- 
ftrumental, I can't be fo perteftly of his mind. 
The Heart (fays this accurate AnatomiftJ of an Animd 
hears a great . Analogy to the Vendulums of thofe Artificid 
Ji3it-3' 
