t 11 3 
Nerve which is inferted and difpetfed thro' its Auri- 
cles, and caufing it to propel Blood more eopioufly 
to the Mufcle. 
XV. 
The Ufe he makes of this is, That a third con* 
curring Caufe of Motion in a Mufcle fhould be 
brought in, in order to render it more complete ; 
and that is, A Fermentation produced by the Animal 
Spirits of the Nerves, and what he calls, the Spirits 
of the Blood ; which he compares to that of any two 
chymical Liquors mixing together : And that when this 
Agitation is begun in the Membranes of the Mufcles, 
the Fluids will be driven, by Their Nifus, in right 
Lines towards the Extremities of the Mufcle , but 
that, finding the Spaces much narrower in them than 
in the Belly of the Mufcle, they are driven back to 
the Middle into the Mufcular Flefh, where the Pores 
are larger, and more lax ; which makes the Mufcle 
fwcll, by the Particles endeavouring to recede from 
each other, and occupy a larger Space 5 as, fays lie, 
happens in all Fermentations : From hence, as the 
Spaces are made larger in this Mufcle, there is Room 
made for the Accefs of more Blood from the Artery 
in the moving Mufcle. Thus Mufcular Motion is 
performed (according to our ingenious Author) by 
three conjund Caufes ; viz. Animal Spirits flowing 
to the Mufcle, Arterial Blood determined in greater 
Quantity than ordinary, and a Fermentatio?i * raifed 
by 
* We fhall find this learned Author’s 'Fermentation , as it Serves to 
account for Mufcular Motion, feix’d on by moft of thofe that followed 
him, without giving him Thanks for it. 
C a 
