190 



QUAKTERLY JOURNAL. 



The fibrin is the constituent of the blood on which its property 

 of coagulation depends. So long as the blood circulates in the 

 living vessels, the fibrin remains dissolved in the serum; but when 

 the blood is drawn, the fibrin coagulates and entangles in its meshes ' 

 the red disks, so that the clot is composed of the fibrin and red I 

 disks. Coagulated fibrin, free from red disks, is a straw colored I 

 tough, stringy mass. 



When, by the act of coagulation, the red disks and the fibrin i 

 have been abstracted from the blood, there remains a colorless, 

 transparent fluid, in which the coagulum floats. This is the serum.{ 

 It resembles in appearance the liquor sanguinis, but as it contains^ 

 no fibrin, it does not coagulate at the temperature of the atmos- 

 phere. Serum consists of water, holding in solution the saline in- 

 gredients of the blood, and albumen. When serum is heated to 

 167° F. the albumen it contains coagulates, but not in a fibrous 

 form like fibrin. The white of egg presents a familiar example of 

 albumen. It is a protein compound, nearly identical in composi- 

 tion with fibrin, and like fibrin, it coagulates, but not in exactly 

 the 5.<ine circumstances. As we shall presently see, albumen has 

 to pass through the form of fibrin before it can be converted into 

 organized tissue. 



The following table shows the ingredients of the blood : 



red disks. 



Blood, composed of, { 



liquor 

 sanguinis. 



fibrin. 



f albumen, 

 serum, < salts, 



( water. 



Or the following diagram of Dr. Mandl, ingeniously shows t 

 composition of the coagulum : 



Blood. 



R. Disks. 



Coagulum. 



