Antiferments and Ferments 17 



against the urea-splitting ferment of Micrococcu* ureae, demonstrating the presence 

 of anti-urease in their serum. Although normal serum and urine antagonize urease, 

 the normal antagonistic substance is distinct from anti-urease. I will further 

 mention that Sachs (1902) has iu a similar manner succeeded in obtaining anti- 

 pepsin, and Gessard (1902, cited above) anti-tyrosin. 



Anti-coagulins have been discovered by Bordet and Geugou (in. 1901). These 

 investigators injected rabbit serum, or plasma, into guinea-pigs and found that the 

 serum of the guinea-pigs acquired the property of preventing the coagulation 

 of rabbits' blood. They attribute the greater part of the anti-coagulating action 

 to the neutralization of the rabbit's fibrin-ferment. The anti-coagulin is specific, 

 or nearly so, in its action, and the experiments made therewith indicate that the 

 fibrin-ferments of different animals possess a different constitution, although 

 capable, all of them, of producing coagulation of the same fibrinogen. The anti- 

 coagulin resists heating to 58-5 0. The authors cite Camus (1901) as having also 

 worked upon anti-coagulins. 



The anti-coagulating action of leech-extract studied by Haycroft, then by 

 Dickinson (1870) and others, can be counteracted by a coagulin. Thus Wendelstadt 

 (1901) found that if he injected leech-extract into rabbits he obtained an anti- 

 body which impeded the anti-coagulating action of the leech-extract. According 

 to this author, the coagulin is chiefly formed in the pancreas, then in the liver and 

 kidneys. The source of these different anti-ferments will doubtless vary consider- 

 ably, depending on their nature. 



