C 32 ] 
Organs of Speech, the Twinkling of Eye-lids, or any. 
others that are done as quick as thought, no more 
than it can be reconciled to the Nature of involun- 
tary Motion, in thofe Mufcles that are not fubjed to 
the Impulfe of the Will. 
XLII. 
His Explanation of Rarefadion, admitting we ex< 
pedcd no Ufe of it in mufcular Motion, feems to 
be very particular too 5 for we can fcarce have any . 
other Caufein View for Rarefadion or Condenfation, 
than Heat or Cold 5 which are fufficient of them- 
felves to prodace thofe Effeds in the mod homoge- 
neous Fluid, without the Ad mixtion of any other. 
Whether Rarefadion can be effeded by any other 
Caufe in the Body, will be hard to determine, if we 
do not fuppofe thofe Spirits to be an acrimonious 
Fluid, capable of caufing a Commotion with the Glo- 
bules of Blood in the Veficles, which would amount 
to a Fermentation ; but our Author fays all is done 
without Fermentation, by this methodical Nifus , 
and Attradion of the Particles of the Spirits to each 
other. 
XLIIL 
Quincf. j mu ft here infert another very remarkable 
Notion propagated by Quincy-> from a Hint 
of Belliniy as it appears in his Explanation of the 
eighth Aphorifm of Sanfforius’s fecond Sedion, 
where he owns his being led by * Belliniy in his 
Notions 
* Opvfcula de Villo (tmtraftiti. 
