[ 42 ] 
t: 
He begins this Explanation with the utrnoft Extend 
Eon of a Mnfcle j and endeavours to prove, that, in 
its Progrefs to Contraction, the whole Mufcle muft 
grow larger in Bulk every Way, by fhortening the 
Axes, and lengthening the Diameters of the Vefides. 
This lie calls their c Diajiole i which happens from the 
Mind’s impelling more than ordinary of the nervous 
Fluid ; but fays, That, when the Will ceafes that Re- 
cruit, the complete Contraction follows by the Nifus 
of the circular Blood -veffels towards the Centre of 
their Veficles. 
LI. 
Now one would be apt to conclude, from this 
Way of Reafoning, that the Velicles ought to lengthen, 
again by the Reftridion of the circular Blood- veffels ; 
for, as their Diameters were lengthened by the Con- 
ttadion of the longitudinal ones, fo, by the Contra- 
ction of their tranfverfe or circular Fibres, the Length 
of the Veficle ought to be increas’d again ,• and, con- 
fequently, the Mufcle ought to return to its State of 
Extcnlion. 
LII. 
Here is one fhort Particular more, that fee ms un- 
intelligible, with which we fhall clofe this Introdu- 
ction: He applies his Experiment on the Frog, to 
prove, that the complete Contradion of the Mufcle 
is excited from the Impulfe of the animal Spirits 
into it ; whereas here he fays, “ If the Mind ceafes 
V her Impulfe, the Nifus of the circular Fibres of 
5 “ the 
