583 
EXPERIMENTS ON DIGESTION. 
which we have only seen precipitates formed similar to those which 
have taken place when an acid was poured into the bile, all these 
things combat this opinion in the most decisive manner. The pre- 
tended flocculi of chyle which are met with in the small intestines, 
are, according to our observation, nothing but collections of mucus, 
which, when the animal has been feeding, are reduced to a white 
fluid in consequence of the absorption of the liquid chyle. The 
intestinal canal cannot retain the chyle in its natural state. The 
chyle is the portion of fluid contained in the small intestine which 
the lymphatic vessels absorb. 
The pancreatic juice, containing a great quantity of albumen, 
a matter analogous to caseine, and another which has the pro- 
perty of being reddened by chlorine, contributes probably to the 
assimilation of the chyme in the small intestines, by means of its 
principal constituents, which contain a great deal of azote, mingling 
with the chyme, and being absorbed with the portion of it that is 
rendered completely fluid. Besides, we have already seen that 
the contents of the small intestine, in proportion as they travel 
along that canal, contain less and less of albumen, of the matter 
analogous to caseine, and of that which is capable of being red- 
dened by chlorine. This is an evident proof that these matters 
are absorbed with the fluidified portion of the aliment. 
It may be still farther alleged as a circumstance favourable to 
the opinion according to which the pancreatic juice assists in the 
assimilation of the alimentary substances, that the pancreas is much 
larger in animals that live on vegetables than in those that are 
nourished by animal food; and, if we may form any conclusion 
from its comparative size, much more fluid would be secreted from 
the first than from the second. Daubenton has made an observa- 
tion, which deserves some thought, on the difference in the size of 
the pancreas in the wild and domestic cat. In the latter, who 
feeds on vegetable as well as animal substances, the gland is much 
larger than in the other, who lives entirely on animal food, not- 
withstanding that, in general bulk, the wild cat considerably sur- 
passes the domesticated one. 
As to the fluid secreted by the mucous membrane of the small 
intestine and its glands, composed of flocculent and of ropy mucus 
with a watery fluid, and of which the secretion is so abundant 
during the flowing of the chyme, we may, perhaps, attribute to it 
the following offices: — 
1. It facilitates the passage of the alimentary boiullie during the 
peristaltic motion of the small intestine, by rendering the chyme 
more liquid, and by moistening and lubricating the internal sur- 
face of the intestine. It also aids the progress of the dissolved 
aliment. 
