Note 33 — Prop. IV.—That some few remedial agents act locally on the mucous surface, either before absorption, or without being absorbed at all. That they are chiefly as follow:—

Possibly some parts of the bile, besides the colouring matter, are truly excrementitious. But part of it is needful in the animal economy, as has been proved by experiment. M. Schwann found that when the contents of the bile-duct in dogs were caused to discharge themselves externally through a fistulous opening in the wall of the abdomen, the animals quickly wasted away and died. In some cases of jaundice, the constituents of the bile appear to be vicariously excreted by the kidneys; and perhaps the great depression produced by that disorder maybe partly accounted for by the impossibility of the re-absorption into the blood of these substances, naturally formed by the liver. Having passed into the urine, there is no provision to enable them to return.