48 RED CORPUSCLES AND FIBRIN-FORMATION. 



Hoppe-Seyler showed that the nucleated blood-corpuscles of birds, 

 when treated with water, give a copious precipitate which resembles 

 fibrin. Heynsius observed a similar result after the blood of fowls 

 had been acted upon by water and dilute solution of common salt, and 

 he also states that nearly 90 per cent, of the total fibrin may be 

 obtained from the washed blood-corpuscles of the horse, when the 

 corpuscles are gradually dissolved. Semmer discovered that he could 

 cause defibrinated frog's blood to coagulate by mixing it with 4 to 6 times 

 its volume of water. On adding 10 to 12 drops of a 0'2 per cent, 

 solution of soda to 1 c.c.m. of defibrinated frog's blood, Semmer and A. 

 Schmidt found that it became converted into a structureless glutinous 

 mass, in which neutralisation with acetic acid produced fibres of fibrin. 

 No fibrin was formed from serum. The same observers diluted 4 c.c.m. 

 of defibrinated frog's blood with 20 c.c.m. of water containing CO.,. 

 The haemoglobin was thereby dissolved in the water, while the colour- 

 less stromata fell to the bottom. When this deposit was mixed with a 

 solution of sodium hydrate, a similar glutinous mass was obtained, 

 which yielded fibrin on being neutralised with acetic acid. No such 

 result was obtained from haemoglobin. 



In 1874, Landois observed under the microscope that the stromata 

 of the red blood- corpuscles of mammals passed into fibrin. If a drop 

 of defibrinated rabbit's blood be placed in serum of frog's blood, with- 

 out mixing them, the red corpuscles can be seen collecting together ; 

 their surfaces are sticky, and they can only be separated by a certain 

 pressure on the cover-glass, whereby some of the new spherical 

 corpuscles are drawn out into threads. The corpuscles soon become 

 spherical, and those at the margin allow the haemoglobin to escape, 

 when the decolourisation progresses, from the margin inwards, until at 

 last there remains a mass of stroma adhering together. The stroma- 

 substance is very sticky, but soon the cell-contours disappear, and the 

 stromata adhere and form fine fibres. Thus (according to Landois) 

 the formation of fibrin from red blood-corpuscles can be traced step by 

 step. The red corpuscles of man and animals, when dissolved in the 

 serum of other animals, show much the same phenomena. 



Stroma-Fibrin and Plasma-Fibrin. Landois calls fibrin formed 

 direct from stroma, stroma-fibrin. Fibrin which is formed in the usual 

 way by the fibrin-factors he calls plasma-fibrin. The stroma-fibrin is 

 closely related chemically to stroma itself; and as yet the two kinds of 

 fibrin have not been sharply distinguished chemically. Substances which 

 rapidly dissolve red corpuscles cause extensive coagulation, e.g., injection 

 of bile or bile salts, or lake-coloured blood, into arteries (Naunyn and 

 Francken). After the injection of foreign blood the newly-injected 

 blood often breaks up in the blood-vessels of the recipient, while 



