[ 30 1 
LXVIII. 
" rj , . f . f i » ’> " ; P 5 ’ • ! 'i r|7 J jL' 
The delicate Texture of the Nerves, as well as 
that of the Brain, implies that the Fluid they convey 
to the Mufcles muft be exquifitely fine. Indeed 
when a Nerve is wounded, there flows from it a 
fweet, fofr, clammy, balfartiic Juice, which no 
doubt is carried, at all other by the evanef- 
cent Nerves to their ultimate Divifions, in order to 
nourifh and preferve the moft minute FibriUa, and 
all their Expsnfions ; and this may properly be 
called the Succus nutritius of the Nerves. But I 
cannot conceive that this vifible Juice has any thing 
to do with the immediate Caufe of voluntary Mo- 
tion i for fo vifcous a Matter could never admit of 
fuch fudden Viciffitudes, as are in mufcular Aftion, 
if it was capable of performing it in other Re- 
fpeds. 
LXIX. 
There are Abundance of Conltderations which 
evince the Exiftence of fome fubcil Spirit in the 
Nerves, much finer than to be the Objeft of our 
Scnfes. We have no Proof, either from Experiment 
or Reafon, of any other inftrumental or phyfical 7 
Caufe of Senle or Motion, but this animal ^yEther 
which is elaborated from the Blood. 
ixx 
