172 COCA. 



in a firm mass upon the stick used for whipping. This mass of fibrin ' 

 M'as then cut into small bits and after having been washed well in physio- 

 logical salt solution, was pressed between layers of filter paper, once more 

 washed in the salt solution and suspended in a volume of that medium 

 corresponding to the volume of the blood from which the fibrin had 

 been derived. In a few cases the blood was not whipped, but centrifugal- 

 ized as soon as possible after being drawn, and the fibrin obtained from 

 the upper layer of coagulated plasma by simple expression of the serum. 

 Instead of salt solution, glycerin was sometimes used for the extraction 

 of the substance sought. 



Extracts of fiibrin obtained from guinea pig, rabbit, man, horse, and 

 dog, were studied, and in these extracts were sought the normal and 

 artificially produced hsemolysins (complement and immune-body) and 

 the hsemagglutinins and bacterial agglutinins. 



The results of the experiments were in every case positive, all the 

 substances mentioned being found in one or another of the extracts 

 examined. 



On the basis of these experiments Bergel recommended the local injec- 

 tion of fibrin in the treatment of abscesses and "other surgical conditions" 

 and reported that he had already obtained favorable results by this 

 practice. 



The latest study of this subject was made by Kindborg,* who ap- 

 proached it from a different standpoint from the other investigators. 



The principal purpose of Kindborg's experiments was to demonstrate 

 the power of fibrin to absorb bactericidal and hsemolytic substances of 

 specific -sera. In order to prove this he left the washed fibrin, which 

 had been sterilized by moist heat, for various lengths of time in contact 

 with bactericidal and hsemolytic serum, and determined in the sera thus 

 treated the resulting* diminution of these substances. 



The experiments with bactericidal sera showed that their power to 

 destroy the respective microorganisms was diminished by prolonged con- 

 tact with fibrin, provided that the experiment was carried out at a 

 temperature of 37° C. ; at room temperature — averaging 10° C— little 

 or no effect was produced. 



In interpreting this observation Kindborg considers only two possibi- 

 lities, namely, the absorption either of antibody or of complement. He 

 ignores the obvious possibility of substances being generated in the 

 fibrin, particularly when the latter has been Icept in contact with an active 

 serum for many hours at body temperature — substances which are 

 injurious to the labile complement. No experiments are reported in his 

 article showing directly that it is not complement which is affected by 

 contact with fibrin. 



'Centralhl. f. Bald. (1908), 48, 335. 



