[ 59 ] 
are fo far weaken'd and deftroyed, that the tyEtloer 
has a Power of flying into the mufcular Fibres 
without any Impulfe or Diredion from the Will, 
after the fame manner it does into the Heart. If 
therefore no Interruption was to be given to the 
Influx of the nervous <^/Ether by the Mufcles 
themfelves, when they were contraded, it would 
follow, that if the Flexors of any Limb were to 
be firft contraded, the Extenfors would not be able 
to recover the Equilibrium , and to be contracted 
in their Turn, without the Afllftance of the Will, 
for if our DoCtrine be right, *viz. that mufcular 
Motion proceeds from the condiment Particles of 
the Fibres being drawn into clofer Contads by the 
attractive Influence of the nervous <iyEther 7 it ne~ 
ceflarily follows, that if the fame Quantity of <^yEther 
was continually to fly into a Mufcle already con- 
tracted, it would have a greater Influence on the 
component Particles fo approximated, than on 
others in the antagonift Mufcles, which are diftraded, 
and confequently touch each other in fewer Points. 
CXXXVIL 
Hence it feems to be evident that fome Impedi- 
ment is given to the Influx of the nervous cl yEther 
when the Mufcles are contracted, or otherwife that 
they would always remain fo* for, though the Will 
may be able to remove fuch little Impediments, and 
to keep the voluntary Mufcles in a State of Con- 
traction for a confiderable Time j yet flnce the vo- 
luntary Mufcles, when affeded with a Palfy, are re- 
gularly and alternately contraded, and have their 
H z Syftoles 
