t 59 3 
XXV. 
Now there does not feem to be Occaflon for 
taking away any Blood from one Mufcle to be de- 
termined to the other j nor has the Do&or explain’d 
how it may be brought about by the Mind ; nor, 
indeed, can I conceive it poffible to hinder the 
Motion of the Blood in the arterial Trunk, leading 
to one Mufcle, while it is fent to the other 5 except 
we could fuppofe the Mind capable of making a Li- 
gature, or other Stri&ure, on the Ramification lead - 
ing to it, leaving the other open at the fame time. 
But no Nerve can have fuch a Power from the Mind 
to aft upon the main Trunk of an Artery ; and there- 
fore the EjfeEl of the Mind’s Impulfe upon the 
Nerve can only be produced, as I have faid, on the 
mod minute venal Canals j where they are capable of 
being prefs’d by the Bellies or Cells of the mufcular 
Fibres that lie by their Sides, and where alone the 
mechanic Structure of the Parts admits of it: Be- 
fides, the arterial Pulfation muft of Neceflity go on s 
to carry Blood to every Part of the Body, being 
propell’d by the fame conftant Force always, in 
healthy Bodies. Hence the Convenience of this out 
Syftem of mufcular Motion is apparent, fuice it is 
carried on at the fame time that the Heart and Ar- 
teries do their Offices without Interruption to either. 
XXVI. 
Again, if it was abfolutely necefiary to mufcular 
Motion, that Blood fhould be taken from an Anta* 
gonift, in order to be fent to the adting Mufcle to 
break the (^/Equilibrium, fome Mufcles, that ferve 
I 2 to 
