Hcemajlatics. 5 5 
thro’ the cut Orifices of the converging Ar- 
teries. 
1 8. Hence we fee how greatly the Velocity 
of the Water is retarded in paffing thro’ the 
feveral Branchings of the Arteries, notwith- 
ftanding the Sum of the Areas of their rrani- 
verfe Scftion is confiderably greater than that 
of the Aorta. And this Retardation mull be 
ftill greater to the Blood which is both a grof- 
fer and more vifeid Fluid than Water, and 
that efpecially in the extream capillary Arte- 
ries which branch off at right Angles, and 
which are about TjTsdi part of an Inch in 
Diameter, fo fine that only fingle Globules of 
Blood can pafs them. 
19. And to this Refillance which the Blood 
meets with in paffing the capillary Aiteries^ 
is owing the great Difference of the Foice of 
the Blood in the Arteries to that in the Veins, 
^iz. as 10 or 12 to I • 
2,0. For iho’ the Velocity of the Blood at its 
firft Entrance into the Aorta, depends on the 
Proportion the Area of its Orifice bears to the 
Quantity thrown into it at each Sjjiok, and 
alfo on the Number of thofe Sjfloles in a giv- 
en time : Yet the real Force of the Blood in 
the Arteries, depends on the Proportion, which 
E 4 
