158 Hdemafiattcs. 
7. This Vein being o.j Inch Diameter, an 
Jnch Length ojf its whole Surface will be 1.57 
fqiiare Inch 5 and a Column of Water whole 
Bafe is a fquare Inch, and its Height a hun- 
dred and forty eight Feet will weigh 
Pounds, which multiplied into the Area of 
an Inch Length of the Vein gives 5)7.7 j 
Pounds, the Weight which that Inch Length 
of Vein fuftained without burfting. And the 
Area of its greatefl: Sedion Lengthwife be" 
ing 0.5 fquare Inch, the Fibres in that Sec- 
tionfuftained 51.45 Pounds without breaking. 
8. Now fuppofe the ordinary Force of the 
Blood in the jugular Vein of a Horfe to be 
equal to twelve Inches Height of Blood, this 
will be but — of the Force which it fuF 
tained without burfting. And fince when 
the Horle ftrained to get loole the Blood rofe 
51 Inches high in the Tube fixed to his 
jugular Vein, and would have rifen fomewhat 
higher if the Tube had been longer, fuppofe 
to fixty Inches, this will be but T^th Part 
of what the Vein was able to fuftain. 
5>. I impelled Air into a Piece of the right 
jugular Vein of a Dog, to fuch a Degree as to 
comprefs the Air in the mercurial Gage^ with 
a Force equal to the Weight of five Atmo- 
fpheres^' 
