CHEMICAL COMPOSITION. 29 



-was mainly seated in the pale corpuscles,* which abound in the washed 

 clot and the buffy coat, and are present in the serum ; and that their 

 efficacy depended on their organisation as elementary cells. In harmony 

 with this latter view, he found on trial that the organised tissues, such 

 as muscle, skin, and spinal marrow, possessed the same power, though 

 in a less degree than the pale corpuscles, in which, as primary cells, the 

 metabolic power is more energetic. 



The remarkable phenomenon described by Buchanan did not 

 obtain the consideration it deserved, and the coagulation of liydrocele- 

 fluid, under the conditions stated, was commonly ascribed to some 

 catalytic action of the substance added, which induced liquid liliriu 

 present in the fluid to solidify. In 1861, however, A. Schmidt, ot 

 Dorpat, apparently unaware of Buchanan's observations, fell upon 

 facts of the same kind, and pursuing the investigation by an elaborate 

 scries of experiments, not only with hydrocele-fluid, but with peri- 

 cardial, peritoneal, and other serous fluids and effusions, which give a 

 like result, has satisfactorily shown that fibrin has no existence in a 

 li(|uid state, but that when it appears as a coagulum in a fluid, it is 

 actually produced then and there by the union of two constituents 

 present in solution, and forthwith shed out as a solid matter. One of 

 these constituents which contributes in largest measure to the product, 

 he n£ime& _fibri?iof/c no lis substance, the other fibnnoj)Iastk substance. In 

 the coagulation of hydrocele-fluid, the former, ov fibrinogen, is already 

 there, while the fibrinoplastin is supplied from the blood. It is not 

 that the latter converts albumin into fibrin, for, after a certain amount 

 of fibrin has been coagulated from the serous fluid, no farther addition 

 will generate more, although abimdance of albumin remains ; and 

 again, a given quantity of fibrinoplastin will not coagulate with equal 

 rapidity and intensity any amount of fluid containing fibrinogen. In 

 short, the fibrinoplastic substance seems to operate not by catalysis, 

 but by combining with the other necessary ingredient. Xow Schmidt 

 has shown that the fibrinoplastic matter presents all the chemical 

 characters of paraglobulin, and is, in fact, nothing else than that 

 substance. This paraglobuliu is not restricted to the red corj^uscles ; 

 it is found in the serum after separation of the clot, and doubtless 

 exists also in the pale corpuscles. Nor is it confined to the blood. 

 From chyle and lymph, and from various organs and tissues of the 

 body, a substance may be obtained having the same reactions and the 

 same fibrino-plastic power. Fibrinogen may be obtained from hydro- 

 cele-fluid in the same manner as paraglobulin from blood-serum {vide 

 infra) ; it very closely resembles paraglobulin in its chemical relations, 

 only it is less soluble in acids and alkalies, and less energetic in all its 

 re-actions. Of course, it exists in blood-plasma, and in the process of 

 coagulation of the blcod combines with paraglobulin to form the fibrin 

 of the clot.f 



* This idea or one similar, has beeu recently re\dved by Alantegazza, who conceives the 

 fibrin to be derived from the pale corpuscles, or at least that their presence is necessary 

 for coagulation to take place. Compare also Burden Sanderson, Handbook for the Physio- 

 logical Laboratory, p. 173. 



t Schmidt, Alex., in Reichert & Du Bois Reymond's Archiv fiir Anat. u. Physiol. 

 1861 and 1S62. For a lucid account of this subject, founded on a confirmatory repeti- 

 tion of Buchanan's and of Si^hmidt's fundamental experiments, see an article on "the 

 Coagulation of the Blood,"' fby Dr. Michael Foster], in the Natural -History Reviewfor 

 1864, p. 157. 



