304 LEO LOEB. 



effect. The fibrin of these latter animals was used as the fibrin 

 of the lobster, or in some instances was for two hours put into 

 lobster serum previous to the experiment, so that substances 

 present in the fibrin which might inhibit coagulation were 

 removed. Lobster fibrin, treated in this way, was active ; the 

 fibrin of rats and rabbits was without effect. If, however, to the 

 lobster serum previously treated with fibrin of rabbits, fibrin of 

 lobster was added, the serum coagulated ; therefore, no substance 

 inhibiting coagulation had been extracted from the mammalian 

 fibrin. 



Small pieces of the pancreas-liver of the lobster entirely pre- 

 vented, as was to be expected, coagulation. 



After pieces of the first lobster fibrin had been put for ten 

 minutes or longer into absolute alcohol, then washed and dried, 

 they lost almost entirely their power to produce coagulation. 

 A trace of the second gelatinous coagulum, however, was some- 

 times still formed around such pieces. Control experiments 

 showed that alcohol passing into the serum was not the cause of 

 this loss of efficiency. 



Pieces of fibrin put into chloroform water over night and even 

 for three days, may still be very efficient, though not quite as 

 active as fresh fibrin. Put into chloroform water for five days 

 they lost to a large extent their efficiency. The addition of i 

 cc. of chloroform water to 4 or 5 cc. of serum, or of a few drops 

 of pure chloroform, to the serum had no more influence on the 

 coagulation than the addition of an equal amount of water. 



Heating of the fibrin in the water-bath to 46 or 47 for 30 

 to 40 minutes, destroyed its efficiency to a great extent, though 

 not completely. Heating up to 5 154 for 40 minutes, destroyed 

 its efficiency entirely or almost so. 



Heating of the serum to 46-50 during 30 minutes, usually 

 prevented the spontaneous coagulation of the serum. If, how- 

 ever, one adds to such serum previously heated, fresh fibrin, the 

 serum coagulates almost as rapidly as normal serum. 



The addition of I cc. of glycerine to 4 cc. of serum did not 

 have any specific inhibiting influence. Also the addition of i 

 cc. of a weak solution of pure gelatine did not have any specific 

 influence. 



