¥he Circulation of the Blood . 119 
many of the Veftels are fo fmall, that even 
fingle Globules cannot poffibly find aPafifage 
thro’ them without being comprcfied into 
oval Shapes : and yet thefe Vefiejs are large 
in Companion of the fined: VeiTels of all, to 
pafs through which, the Globules muff be 
divided and fubdivided into their fmalleft 
and moil: minute component Globules. 
t 
It is amazing to obferve how careful 
Providence has been to prevent the Blood 
from coagulating, or cohering in Mafifes dan¬ 
gerous to Life, by the very Difpofition of 
the Vefiels it runs through : which, whether 
feparating or uniting, are fo contrived as to 
caufe the Globules to come frequently to¬ 
gether with a brifk Collifion, or finking 
againft each other. The Arteries^ for Ex¬ 
ample, which convey the Blood from the 
Heart to the Extremities of the Animal, 
and in their Progrefs continually leffen their 
Diameters, and divide into imaller Branches 
aim oft ad infinitum ; in thefe Arteries , X 
fay, at every fuch Divifion, many of the 
Globules of the Blood muft rufh, with a 
Cpnfiderable Force, againft an Angle direct¬ 
ly in theipWay; whence recoiling back on 
tjiofe immediately behind, they muft ftrike 
Upon one another, and caufe a Kind of 
Commotion, ere the Current can . divide 
readily into the two fmaller Branches. See 
pig. III, Plate —Ifi the Veins s which. 
