RELATIONS. 
151 
it waits to undergo a great chemical action, which we call 
digestion: when digested, it is delivered through an orifice, 
which opens and shuts as there is occasion, into the first 
intestine; there, after being mixed with certain proper in¬ 
gredients, poured through a hole in the side of the vessel, 
it is farther dissolved; in this state, the milk, chyle, or 
part which is wanted, and which is suited for animal nour¬ 
ishment, is strained off by the mouths of very small tubes, 
opening into the cavity of the intestines: thus freed from 
its grosser parts, the percolated fluid is carried by a long, 
winding, but traceable course, into the main stream of the 
old circulation; which conveys it, in its progress, to every 
part of the body. Now, I say again, compare this with the 
process of a manufactory; with the making of cider, for ex¬ 
ample ; with the bruising of the apples in the mill, the squeez¬ 
ing of them when so bruised in the press, the fermentation 
in the vat, the bestowing of the liquor thus fermented in the 
hogsheads, the drawing off into bottles, the pouring out for 
use into the glass. Let any one show me any difference 
between these two cases, as to the point of contrivance. 
That which is at present under our consideration, the “ re- 
’ation” of the parts successively employed, is not more 
clear in the last case, than in the first. The aptness of the 
jaws and teeth to prepare the food for the stomach, is, at 
least, as manifest, as that of the cider-mill to crush the 
apples for the press. The concoction of the food in the 
stomach is as necessary for its future use, as the fermenta¬ 
tion of the stum in the vat is to the perfection of the liquor. 
The disposal of the aliment afterwards; the action and 
change which it undergoes, the route which it is made to 
take, in order that, and until that, it arrive at its destina¬ 
tion, is more complex indeed and intricate, but, in the 
midst of complication and intricacy, as evident and certain, 
as is the apparatus of cocks, pipes, tunnels, for transferring 
the cider from one vessel to another; of barrels and bottles 
for preserving it till fit for use, or of cups and glasses for 
bringing it, when wanted, to the lip of the consumer. The 
character of the machinery is in both cases this, that one 
part answers to another part, and every part to the final 
result. 
This parallel, between the alimentary operation and some 
of the processes of art, might be carried farther into detail. 
Spallanzani has remarked* a circumstantial resemblance 
between the stomachs of gallinaceous fowls and the struc- 
* Diss. I. Sect liv. 
