THE CLOT. 201 



albumen may form either a gelatinous and milky, or a flocculent, 

 or a membranous coagulum, without having experienced any alter- 

 ation in its elementary composition, we cannot admit the necessity 

 of regarding the buffy fibrin of the inflammatory coat as chemically 

 different from that which is separated, in a crumbling or flocculent 

 form from tar-like blood. 



The form of the coagulum mainly depends upon the relations of 

 the blood-corpuscles to which we have already referred. We 

 have seen that, under certain conditions, the blood-corpuscles are 

 disposed to approximate to one another by their flat sides, thus 

 assuming a cylindrical form, and that in this manner they 

 more readily displace the column of fluid which supported them, 

 and sink more rapidly ; whilst those cells which are of a jagged, 

 twisted, or spherically distended form, impede such a cohesion, 

 and give rise to a more prolonged suspension of the molecules. 

 The different forms of the clot must, therefore, obviously depend 

 upon the different sinking capacity of the blood-corpuscles. 



The rapidity or slowness with which the fibrin is separated and 

 consolidated, exerts in the same manner a determinate influence on 

 the form of the clot. The differences existing in these proximate 

 causes prove how difficult it is to explain in a special case the 

 remote causes which may give rise to any definite form of the 

 clot. If we here take into account the two proximate causes of 

 difference, namely, the time of coagulation of the fibrin and the 

 sinking capacity of the blood-corpuscles, we find two cases 

 especially which give rise to a different conformation of the clot, 

 namely, rapid coagulation of the fibrin with little tendency of the 

 corpuscles to cohere, and slow coagulation of the fibrin with rapid 

 sinking of the corpuscles. 



Henle first drew attention to the fact that the red sediments 

 of blood-corpuscles, which are often deposited from the blood 

 when there is a dense clot, are owing to the fibrin coagulating and 

 becoming contracted before the corpuscles had assumed the roll- 

 like or nummular form; on the contraction of the gelatinised 

 fibrin, a large number of the loosely connected or wholly isolated 

 blood-corpuscles are again expressed, by which means the serum 

 is for a time rendered turbid and red, until they afterwards separate 

 into the above mentioned sediment, which readily admits of being 

 again disturbed. Zimmermann, who confirmed this view of 

 Henle's by a microscopical examination of the red deposit, found, 

 moreover, that besides this sediment there was always present a 



