282 



PHILIP HADLEY 



seven to ten days with forty-eight-hour broth cultures of strain 

 48, killed by heating at 63° for one-half hour.^ 



S, subcutaneous (in the neck). 



M, intramuscular (in the breast muscle). 



* Reinforced with 0.000,01 cc. culture 48, March 30. 



No reactions followed the immunizing inoculations with killed 

 cultures. Two weeks after the last immunizing dose all the 

 principals together with two controls were infected with 0.000,01 

 cc. of culture 48, as shown in the table, and with the results 

 indicated.' 



These protocols are similar to many others on record and 

 indicate how free the B. avisepticus cultures were from anything 

 that could be regarded as bacterial toxins. One can readily 

 imagine the results that would follow had B. diphtheriae or 

 some other toxic culture been used in these experiments in place 

 of the fowl cholera bacterium 



The instances mentioned above involved the use of killed 

 cultures and the doses were not administered intravenously as 

 was the case in Dr. Bull's tests on rabbits and dogs in which he 

 obtained results that suggested acute intoxication. In order 



2 In this particular test, in order to obtain a more concentrated suspension 

 of bacteria, the cultures were centrifuged and two-thirds of the supernatant 

 medium poured off. The sediment was re-suspended in the remaining one-third 

 and injected. 



' These data will be presented at a later date in connection with the subject of 

 immunization by means of killed cultures. 



