[«> I 
LECTURE II. 
XLIII. 
Read March 26. N my former Lecture I endeavour’d 
Principles of the mufcular Fibres, and to Ihew the 
true Caufe of their Cohefion, Tenfion, and Elafti- 
city. In this, I hope, I fhall make it appear, ift> 
That every Fibre conftituting a Mufcle is tubular , 
and of a cylindrical Shape, or very nearly fuch; 
and not a String, or Chain of Bladders, according 
to an Hypothecs which has been too long and too 
generally received, idly. That the corpufcular At- 
tradion between the component Particles of the Fi- 
bres is fo far increafed and ftrengthen’d by the In- 
fluence of the nervous r^/Ether, which is always at 
the Command of the Will, as to purfe up and 
(horten every Fibre in its Length, whereby an In- 
tumefcence arifes in the Belly of the Mufcle, though 
it is contracted in its other Dimenftons, fo as, in 
the Whole, to pofiefs lefs Room. 
Being favoured with the Ufe of a moft excellent 
Microfcope, I made the following Experiments. 
to explore the feveral conftituent 
XL1V. 
ijl, 
