[ 57 ] 
their Diameters, while the Veins are fqueezed quite - 
empty, and the whole Mufcle is fliortened, and its 
Action performed. 
XXII. 
The Degree of Contraction in a Mufcle is always 
as the Force neceffary to perform fuch or fuch an 
ACtion ; and this is determined by the Degree of the 
Inflation of the Cells $ that is, if the Force required 
be but inconfiderable, then the Impulfe of the Mind 
will be but inconfiderable, and confequently the Cells 
will have but an inconfiderable Inflation ; therefore 
the Preffure of the Cells on the minute Veins will 
be in Proportion : So that of the arterial Blood, tho 3 
it flows, always in the fame Quantity into the Muf- 
cle ; yet, becaufe the Preflurc of the Cells on the 
Veins is but fmall, a proportional Part will go on, 
and return by the Veins 5 and therefore the Reple- 
tion of the Mufcle, and its Contraction, can be but 
inconfiderable: Whereas, when a violent Motion is 
to be performed, then the Degree of Inflation of the 
Cells will be very great, the Blood totally flopped in 
the Veins, the Arteries increafed in Diameter, and 
the Mufcle fhortened even to its ultimate State of 
Contraction, if requifite. 
XXIII. 
While the Circulation is thus hindered in the act- 
ing Mufcle, there can be no Diforder occafioned, 
either in the Oeconomy of the Circulation in other 
Parts of the Body, nor in the particular Conftitution 
of the Mufcle itfelf. The former Cafe is certain from 
our daily Experience of Amputations ; wherein, 
I tho’ 
