( ^34 ) 
pos'd the Heat of the Stomach to be the great Gaufe of 
the Digeftion of the Food. 
There are others that make the Stomach it felf to be 
the great Inftrument of Digeftion, but in a different 
manner : And they fuppofe it to be performed by an At- 
trition, as if the Stomack, by thofe repeated Motions, 
which are the neceffary ESkds of Refpiration, when it 
is diftended by the Aliment, did both rub or grind off" 
fome minuter Particles from the groffer Parts, and by 
continually agitating the Mafs of Food, make thofe 
Parts, which are not contiguous to the Stomack, ftrike 
one againft another, and break one another in pieces, 
until they are all attenuated. It is evident enough, that 
the fides of the Stomack do in Expiration prefs upon the 
Contenta, fo as to oblige, at leaft fome Parts of them, 
every time the Mufcles of the Abdomen are contraded, 
to move and fliift their Places. So in Infpiration, when 
the Diaphragme and Liver prffs upon the upper Part of 
the Stomack, the Aliment muft be moved again. So 
that by thefe reciprocal Motions, that part of the Food, 
which is contiguous to the Stomack, and moves in a 
Line parallel to it, muft rub againft it : And all the other 
Parts being moved by fuch aComprefTion, as gives them 
a different Tendency, it is certain they muft be conti- 
nually ftriking one againft another. And for Bread, 
and fuch Things as are made of Flower, that will be 
foften'd and diflblv'd with any common Liquid, that 
Agitation of the Stomack, which moves them in Re- 
fpiration, might (eem fufficient to break and diflblve 
them, when they are fufficiently moiften'd with a Fluid. 
Yet this cannot be thought enough to break and digeft 
Fle(h-meat, Fruits, or any other thing that will not be 
foftned and diftolv'd in Water, or (bme fuch Liquid. 
But altho' this Motion of the Aliment, caufed by Refpi. 
latton^ does not adually digeft it, yet it has a great 
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