[ 57 ] 
Will * or otherwife Cramps and Convulfions would 
perpetually happen. But in thofe which fupply the 
Heart, the Motion of the ^yEther through them 
cannot have any Affiftance or Impulfe from the 
Will, as nor being in the leaft under its Influence 5 
fo that the Vibrations of the Meninges of the Brain, 
and the Dilatations of the Arteries may be fuppofed 
to be the Agents which propel the cyEther towards 
the Heart. 
CXXXII. 
Hence then it feems to follow, that the alternate 
Contractions of the Heart may proceed from the 
alternate Imprellions made on the Nerves, by the 
Meninges of the Brain, and Dilatations of the Arte- 
ries. 
CXXXIII. 
Upon opening the Sculls of living Animals, the 
*Dura Mater may plainly be feen to have its Syfto- 
les and "Diaftoles correfponding to thofe of the Ar- 
teries 5 but fince the Heart continues to beat after 
the Head is cut off, or even after it is taken out of 
the Body, where there cannot be any alternate Suc- 
cuflions made on the Nerves by the Meninges of 
the Brain, or by the Pulfation of the Arteries, it 
feems reafonable to believe that this Alternation is 
occafion’d by fome Impediment being given to any 
further Influx of the o 'Ether into the mufcular 
Fibres of the Heart, when it is fully contracted 5 or 
otherwife, the Heart would conftantly remain in a 
H State 
