the Bile in the Process of Digestion. 343 
with this difference, however, that it became of a thicker con- 
sistence in proportion as it was at a greater distance from the 
stomach: and that, as it approached the termination of the 
ileum in the cecum, the fluid part of it had altogether disap- 
peared, and there remained only a solid substance, differing in 
appearance from ordinary feces. The lacteals contained a 
transparent fluid, which I suppose to have consisted partly of 
lymph, partly of the more fluid part of the chyme, which had 
become absorbed. 
I conceive that these experiments are sufficient to prove that 
the office of the bile is to change the nutritious part of the 
chyme into chyle, and to separate from it the excrementitious 
matter. An observation will here occur to the physiologist. 
If the bile be of so much importance in the animal economy, 
how is it that persons occasionally live for a considerable time, 
in whom the flow of bile into the duodenum is interrupted ? 
On this point it may be remarked, 1st, That it seldom happens 
that the obstruction of the choledoch duct from disease is so 
complete as to prevent the passage of the bile altogether; and 
the circumstance of the evacuations being of a white colour, 
may prove the deficiency, but does not prove the total absence of 
bile. 2dly, That in the very few authenticated cases, which have 
occurred of total obliteration of the choledoch duct in the human 
subject, there has been, I believe, always extreme emaciation, 
shewing that the function of nutrition was not properly performed. 
3dly, That the fact of individuals having occasionally lived for a 
few weeks or months under these circumstances only proves that 
nutrition may take place to some extent without chyle being 
formed. In my experiments I found that the more fluid parts of 
the chyme had been absorbed, and probably this would have 
been sufficient to maintain life during a limited period of time. 
In the prosecution of this inquiry, a circumstance occurred, 
which seems not unworthy of notice, although not imme- 
diately connected with the subject of digestion. The ligature 
applied round the choledoch duct was always a single silk 
thread, the ends of which were cut off close to the knot. If the 
animal was allowed to live, he became jaundiced. The tunice 
