1 6 2 Hcemajlatks. 
hindering its Expiration at the Mouth and 
Nofe ; And as we cannot thus hold our Breath 
long, fo neither can we thus exert our utmoft 
Strength long, without fome (hort Intervals of 
Abatement. And during this draining we 
conftantly fee the Veins of our Neck, Fore- 
head and Temples much diftended \ the Blood 
being forcibly impelled into them from the 
much contrafted Abdomerty in whofe large 
Veins there is Plenty of it in ftorc ; for the 
Number and Capacity of all the Veins of the 
Body is obferved to be much greater than that 
of the Arteries. 
ly. And while the Blood is thus ftrongly 
compreded in the Veins, it muft proportion- 
ably retard its Padage out of the Arteries, 
it being therefore there accumulated, will ac- 
quire an additional Force of four Feet per- 
pendicular Height, that is in all equal to 1 
Feet in the draining Mare : And an additio- 
nal Force of twenty four Inches, equal in all 
to eight Feet and eight Inches in the draining 
Dog 5 whereby the Blood being impelled more 
forcibly into the Mufcles enables them to aft 
the more vigoroudy. 
16 , But the free natural Courfe of the arte- 
rial Blood into the Veins is not only retarded 
by 
