The resolution of fibrinous exudates,with exhibition of specimens

The purpose of the experiments which are described has been to determine the part played by enzymes in the resolution of a fibrinous exudate. When turpentine is injected into the subcutaneous tissue of the dog, an abscess results, but when an equal quantity of turpentine is injected into the pleural cavity, there is abundant exudation of coagulable fluid and the serous surfaces are covered by thick layers of fibrin. Accumulation of fluid which can be followed during life by percussion of the animal's chest reaches a maximum at the end of three days, and then gradually subsides so that at the end of six days, in most instances, the cavity contains no fluid. Fibrin, though diminished in amount, is still present, and gradually disappears, so that at the end of two or three weeks, the cavity has returned to the normal, save for a few organized adhesions.

During the early stage of the inflammation, fibrinous exudate, freed from the serum by washing in salt solution, undergoes digestion when suspended in an alkaline (0.2 per cent, sodium carbonate) or in an acid medium (0.2 per cent, acetic acid). At the end of six days, at a time when fluid has disappeared from the pleural cavity, digestion fails to occur in an alkaline medium, but occurs with great activity in the presence of acid.

During the first stage of the inflammatory reaction, when fluid is abundant and the fibrin which is present digests in the presence of alkali, polynuclear leucocytes are very numerous in the meshes of the fibrin. In the second stage, when fluid has in great part disappeared, and the fibrin contains only one enzyme digesting in the presence of acid, polynuclear leucocytes have disappeared and only mononuclear cells are ernbedded in the fibrin.