De. Buchanan on the Fibrin contained in the Animal Fluids. 137 



to bo analogous to the process by which serum exposed to the air is 

 converted into an opaque liquid, which collects at the bottom, and 

 which resembles pus in all its sensible qualities, but consists of irre- 

 gular flocks instead of globules ; and it is not improbable, that some 

 of the less healthy forms of pus which are more flocculent than glo- 

 bular, originate in a similar way within the body. 



I believe that pus is never formed, as many maintain, in inflamed 

 vessels and secreted from them. The formation of pus is most dis- 

 tinctly observed in blisters upon the skin, in which we can watch the 

 whole steps of the process, by which effused serum is converted into pus. 

 Tho same gradual conversion of effused scrum into pus is observed in 

 inflamed serous cavities. It may also be observed in the clear liquid 

 which exudes from ulcerated surfaces, and which speedily thickens 

 into pus. 



V. — COAGULABLE LYMPH. 



The fluid named coagulable lymph, is, probably, in every respect 

 similar to the blister liquid, except in this, that in the latter, one 

 of tho two serous elements necessary for the development of the 

 fibrinous corpuscles, is effused in a greatly disproportionate quantity, 

 and hence the production of organized fibrin goes on comparatively 

 slowly. In coagulable lymph, on the other hand, the two elements 

 are effused in exactly the necessary proportions. Organized fibrin is 

 formed therefore with great rapidity, and hence the utility of coagu- 

 lable lymph in repairing solutions of continuity, and loss of substance 

 of tlie body. The fibrinous globules developed in coagulable lymph, 

 are either entirely converted into new tissues, as in wounds which heal 

 by the first intention, or simple fractures of the bones ; or they are 

 partly converted into granulations and partly into pus, as in healing 

 ulcers and abscesses ; or they may bo entirely changed into pus of 

 various character, by the process described above. The corpuscles 

 observed in coagulable lymph, vary more in size, and are less regular 

 in form than those of the blister liquid. 



VI. — LYldPn OF THE LYMPHATIC SYSTEM. 



All those who have observed the lymph drawn from the thoracic 

 duct and lymphatic vessels, describe it as possessing the property of 

 spontaneous coagulability. Gerber represents it as not being coagu- 

 lable in the extreme lymphatic vessels, and only to acquire that pro- 

 perty as it passes towards the heart 



The account given of its appearance under the microscope varies ; 

 but most observers agree that it contains corpuscles more minute than 

 the corpuscles of the blood. There is much reason to think, that the 

 description which has been given of it, by one of the most eminent 

 physiologists of the present day, (see Midler's Physiology : Translation, 

 p. 259,) ought to bo applied to the coagulable lymph from a small 



