48 RESEARCHES OF A. SCHMIDT. THE FIBRIN-FERMENT. [BOOK I. 



statement of the way in which the two bodies which he believed to 

 be fibrin-generators, associated themselves in the formation of fibrin. 

 He however believed that he had proved the actual co-operation of 

 paraglobulin in the formation of fibrin by shewing that the amount of 

 fibrin which separates from a solution containing paraglobulin is to a 

 certain extent influenced by the amount of paraglobulin added to 

 that fluid. 



The Fibrin-fmnent. 



Such were the principal facts published by A. Schmidt anterior 

 to 1872, and the views which he based upon them. It will be seen 

 how widely these views differed from those of Buchanan and of Denis, 

 each of whom was acquainted with many of the most important facts 

 independently discovered by the Dorpat professor. But in their turn 

 the views of Schmidt soon received from their author most important 

 modifications. 



Schmidt's theory of coagulation postulated that when a fluid 

 containing fibrinogen did not coagulate spontaneously, this was due 

 to an absence of the fibrinoplastic substance. But he discovered 

 that the two fibrin-generators may be present in the same fluid and 

 yet coagulation not occur. Hydrocele fluid is for instance by no 

 means free from paraglobulin and may sometimes contain considerable 

 quantities of that body, without coagulating spontaneously, though the 

 addition of blood or of blood serum will lead to its coagulation. Does 

 blood or blood serum then contain some constituent other than 

 paraglobulin which exerts a fibrinoplastic action ? 



It appears so, and this body Schmidt believes to be of the nature of 

 a ferment which is liberated after the blood is removed from the blood- 

 vessels, and which in an impure condition he prepares as follows 1 : 



Schmidt's Blood or, still better, serum separated from the clot of 

 coagulated blood, is treated with twenty times its volume 

 soTutto^of ^ a l con l a]Q d the mixture set aside in a stoppered bottle 

 Fibrin-fer- f r a t least a fortnight, but preferably for a period of three 

 ment. months. The alcohol coagulates the proteid matters of the 



plasma and corpuscles as well as the haemoglobin contained in the 

 latter, and by the prolonged action of alcohol these various matters are 

 for the most part rendered insoluble in water. The insoluble matter 

 is then collected on a filter and dried over sulphuric acid, and, when 

 dry, finely pulverized. The powder is treated with water ; the aqueous 

 solution is found to contain the so-called fibrin-ferment. 



Such a solution when added to a liquid which contains fibrinogen 

 and paraglobulin but which does not coagulate spontaneously, often 

 rapidly gives rise to a coagulum. The amount of fibrin which 

 separates is, according to Schmidt, in no respect influenced by the 



1 A. Schmidt, "Neue Untersuchungen iiber die Faserstoffgerinnung." Pfliiger's 

 Archiv, Vol. vi. (1872) p. 445. 



