68 



Scientific Proceedings (52). 



attempts were made to determine whether or not the specific 

 antibodies, upon which the intraperitoneal lysis may be supposed 

 to depend, are present in the circulating fluids. 



To test this, guinea-pigs, rabbits and dogs were made tubercu- 

 lous by inoculating them subcutaneously with tubercle bacilli. 

 After an interval of from five to eight weeks, these animals were 

 bled and their blood tested in vitro and in vivo. In a number of 

 these experiments direct transfusion of the blood was made from 

 the tuberculous animals into normal animals, an amount o blood 

 often as great as three quarters of the total blood-volume being 

 thus passed into the circulating system of the normal animals, the 

 normal animals having been previously bled to free them as much 

 as possible from normal blood. The transfused animals were sub- 

 sequently tested by intraperitoneal injections of tubercle bacilli. 



Neither in the test-tube experiments, nor in normal animals 

 injected subcutaneously, intravenously or intraperitoneally with 

 tuberculous serum, nor even in the normal animals directly trans- 

 fused with large quantities of the unaltered blood of tuberculous 

 animals, has the reaction thus far been obtained. The substances 

 responsible for the heightened peritoneal resistance, therefore, 

 apparently do not exist in appreciable quantities as circulating 

 antibodies, at least at the stage of the disease studied. The 

 heightened tuberculous resistance, therefore, is apparently due to 

 substances held in fixed tissue cells. 



Evidences of tuberculolytic substances have, however, been 

 obtained in the peritoneal fluids of tuberculous guinea-pigs, soon 

 after the introduction of tubercle bacilli. If these fluids are with- 

 drawn, centrifuged free from formed elements and then introduced 

 into the peritoneal cavities of normal guinea-pigs, they confer 

 upon the normal peritoneal cavities a slight power of destroying 

 tubercle bacilli. It is suggested, therefore, that fixed tuberculolysins 

 are set free by the peritoneal cells in response to the presence of 

 tubercle bacilli, and that these lysins account for the heightened 

 resistance to intraperitoneal reinoculation with tubercle bacilli. 



