136 Dr. Buchanan on the Fibrin contained in the Animal Fluids. 



ally happens, become filamentous, always affect a reticular arrange- 

 ment. This arrangement is less easily seen under the microscope than 

 with the naked eye. The coagulum of the blister liquid does ^ot show 

 it so distinctly as a loose coagulum, such as that of blood diluted with 

 water before coagulation, or the coagulum which forms in the mixture 

 of the serum of the blood with that of the serous cavities. 



6. Identity of the fibrinous vesicles and granules, with cells and cell- 

 germs. — The tendency which the fibrinous granules and vesicles have 

 to transform themselves into cellular membrane, appears to mo to 

 render it probable, that they are identical with the cell-germs and 

 cells out of which the tissues of the body are developed. According 

 to Dr. Barry, these cells are not distinguishable under the micro- 

 scope from blood-corpuscles, a character which applies exactly to the 

 vesicles of the blister-liquid. 



7. Conversion of the fibrinous vesicles into Pus globules. — When the 

 actions going on upon the vesicated surface are of a healthy char- 

 acter, as soon as the fibrinous corpuscles are sufficiently abundant, 

 they concrete into a coagulum. This coagulum hardens into a crust 

 or scab, under the protection of which the epidermis is reproduced, 

 and then the crust falls off. When, on the other hand, the actions are 

 of an unhealthy character, whether from the severity of the original 

 injury, or from the rupturo of the blister, and the consequent irrita- 

 tion by the atmospheric air of the raw surface, the fibrinous globules 

 gradually change their colour, and are converted into pus globules. 

 This change seems to be effected by the liquid contained within the 

 membranous vesicles becoming more and more opaque, and as this 

 change of colour takes place, the globules gradually lose their attrac- 

 tive power over each other ; hence the globules of laudable pus when 

 examined under the microscope appear perfectly distinct, and have 

 no tendency to aggregation. There are, however, upon all inflamed 

 surfaces globules and granules in every stage of transition, from the 

 transparent fibrinous, to the opaque purulent state. Many of these 

 are more or less adherent, and constitute the flakes and layers of 

 coagulable lymph observed upon inflamed surfaces. When these 

 are examined under the microscope, they are found to consist of 

 corpuscles of various sizes irregularly aggregated, and hence seems to 

 have sprung the notion entertained by some pathologists, that pus 

 globules are formed by the disintegration of globules of fibrin, or of 

 blood ; the former of which, from an erroneous theory (as appears to 

 me), of the mode in which they are produced, have been named 

 " exudation globules.^' This notion is best refuted by observing the 

 steps of the process described above ; and also by the size of the great 

 majority of the globules of laudable pus, thus originating, being equal 

 or little inferior to that of the blood globules or of those of fibrin. 



With respect to the process by which the transparent liquid within 

 the fibrinous capsules is converted into an opaque one, I believe it 



