[ 42 I 
inconfiftent with many Things relating to the Ani- 
mal Oeconomy, and contrary to Tome known Ex- 
periments, might give Rife to the vibrating Scheme, 
where the Exiftence of the animal Spirits is denied* 
and where it is fuppofed that both Senfation and 
mufcular Motion may be performed merely by the 
Elafticity of the Nerves, and Contractions firft of 
all begun in the Brain, and fo communicated to 
the fleffiy Fibres : But this is fo immechanical a 
Notion as not to deferve an Anfwerj it being im- 
poffible for a vibrating Motion in one Cord or 
String, were it ever fo elaftic, to caufe a Contrac- 
tion in another without the Intervention of fom^ 
Fluid, 
XCYIIL 
!i' 
' hfernari 
Old 6 w thill 
I (hall conclude this LeCiure therefore. with oB* 
ferving, that the Exiftence of an atheredl Medium 
in the Nerves is paft all manner of Doubt > it being 
otherwife contrary to the known Laws- of Nature 
for the Nerves to be the Caufe of mufcular Mo- 
tion if they were folid, or did not admit the moft 
lubtil Fluid, fecreted by the Glands pf the Brain, to 
pafs through them* 
i 
XCIX. 
And fince it is known from Experiment, that 
the Mufcles grow lefs in. Adion, and, confcqucntly, 
the conftituent Particles of every Fibre mud run, 
nearer together before fuch a Thanomenon can hap- 
pen ; we think it very manifed that this Property of 
Condridion arifes from the Ptmciple of corpufcu- 
