[ 34 ] 
voluntary Action ; for here being no Influx of the 
nervous <^/Ether to increafe the corpufcular Attrac- 
tion, the Mufcle is fhortened only by the inherent 
mutual Attraction between the conftituent Particles 
of its Fibres, without any Matter being fuperadded. 
This kind of Contraction therefore is evidently tha 
State to which the elaflic Fibres, tend by a conti- 
nual Conatus in the component Particles to acceda 
towards each other without the Afliftance of the 
nervous <^yEther ,• fo that this natural Vis motrix 
in the mufculous Fibres is no more than what we 
mean by their Elafticity, or reftitutive Property; It 
feems however to be demonftrated from hence, that 
mpfcular Action, and Elafticity in the Fibres, , pro- 
ceed from the fame Caufe in different Degrees $ 
<viz>. from corpufcular Attraction. 
LXXV1L 
Let us now endeavour to corroborate thefe ArgiK 
ments by fome fuitable Obfervations. 
LXXVIIL 
\ft. From what has been faid we may conceive 
more readily, than we know ho\v to exprefs, that 
the Will has a Power to direct the athereal Me- 
dium contain'd in the Nerves, to any of the volun- 
tary Mufcles, with fuch a Degree of Celerixy as it 
pleafes j and to flop the Influx as fuddenlyv 
LXXIX. 
• » . I » 1 ; > i « j \ 
idly. It is evident that the Coats, or carnous Sub* 
fiance of every Fibre, mud necefiarily increafe in its 
Thicknefs, 
