[ c 2 9 1 
XXXIX. 
This being pre-fuppofed, fays he, the Particles of 
the fpirituous Juice of the Nerves are fo very fubtile, 
delicate, and tender, that their Spicula , which at the 
mod gentle Touch are blunted, are only capable 
of opening the mod minute Pores of the Particles 
of the Blood, from which immediately that more 
fubtile elafiic Aura , that was condenfed before, 
rufhes forth, and expands itfelf, thereby dwelling the 
Whole at once ; but, becaufe of the exceeding Mi- 
nutenefs of its Particles, it freely breaks out thro’ the 
open Pores of the Mufcle, and flies off into the am- 
bient Air. Hence the Mufcle muft of Neceflity grow 
lax in a Moment after its Jntumefcence * unlefs new 
Drops of the nervous Juice continually fall into ir, 
creating a Succeflion of Fermentations, and fo keep 
it in a conftant State of Inflation *. 
XL r 
This is the Sum of the Opinion of that great Ge- 
nius the famous Bernouilli , touching the Manner in 
which mufcular Motion is performed : The next is 
that of one as eminent, the learned Keill, but whofe 
Sentiments of the Matter agree well with thofe be- 
fore him. He defines a Mufcle to be “ a Bundle of 
“ parallel Plates of flcfhy Fibres, which are com- 
“ pofed of other fmailer Fibres, and each final ler 
4 “ Fibre 
* We fhall find the following Author fays no more than Bernou.- 
plb explaining it only a different Way, 
