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the circulation of the blood through the whole body 
and extremities ; in real fifhes, the force of the heart 
is alone capable of fending the blood to every part, as 
they are not furnifhed with limbs or extremities ; but 
in the others mentioned, being all furnifhed with 
extremities, refpiration is an afliftant force to the arte- 
ries in fending blood to the extremities, which, being 
fo remote from the heart, have need of fuch afiiftance ; 
otherwife the circulation would be very languid in 
thefe parts; thus we fee, that in perfons fubjed to 
aflhmatic complaints, the circulation grows languid, 
the legs grow cold and oedematous, and other parts 
fufter by the defed in refpiration. 
A fecond ufe of breathing is that, in infpiration, the 
variety of particles of different qualities, which float 
always in the air, might be drawn into the lungs, to be 
infinuated into the mafs of blood, being highly necef- 
fary to contemperate and cool the agitated mafs, and 
to contribute refined pabulum to the finer parts of it, 
W'hich, meeting with the daily fupply of chyle, ferves 
to afiimilate and more intimately mix the mafs, and 
render its conflitution the fitter for fupporting the life 
of the animal. Therefore it is, that valetudinarians, 
by changing foul or unwholefome air for a free, good, 
open air, often recover from lingring difeafes. 
And a third principal ufe of refpiration is, to pro- 
mote the exhibition of a voice in animals ; which all 
thofe that live on the land do according to their fpeci- 
fic natures. 
From thefe confiderations it appears, beyond 
contradidion, that thephocae of every kind are under 
an abfolute neceffity of making the land their prin- 
cipal refidence; but there is another very convincing 
argument 
