54 



Scientific Proceedings (iio). 



after heating to 70 0 for 30 minutes, and in 3 other experiments 

 heating to from 75 0 to 8o° for 30 minutes almost completely 

 destroyed the toxicity of 6 and 12 hour typhoid nitrates. 



There was, thus, marked similarity between the influenza and 

 the typhoid substances, in all these particulars. 



With both of these organisms experiments were now done with 

 growths on solid media. 



Cultures on various solid media were allowed to grow 6 hours 

 in the case of the typhoid bacilli, in order to prevent as far as 

 possible any bacterial cell death. Filtrates from such washings 

 regularly produced sickness analogous to that described above. 



Although acute death was sometimes obtained, in general the 

 filtrates of washings of typhoid cultures as young as these have 

 not killed, producing only marked illness after the regular incuba- 

 tion time. 



With the influenza bacillus it was necessary, because of the 

 nature of the organism to grow the cultures on chocolate agar. 

 The shortest period of growth of these organisms on solid media 

 was 12 hours. 



Isolated experiments were done with other bacteria. Toxic 

 filtrates were obtained from a 23-hour meningococcus culture on 

 horse-serum-hormone-broth; from a 53^-hour culture of prodigio- 

 sus on rabbit-serum-hormone-broth, and mild reactions were 

 obtained with a similarly prepared 23-hour Shiga bacillus culture 

 filtrate. 



With solid media washings, we produced definite sickness 

 after the ordinary incubation time, and death in 18 hours with a 

 filtrate from the washings of a 20-hour prodigiosus culture on 

 hormone agar, and 2 deaths (in 2 and 2> l A hours, respectively) 

 with filtered washings of 5^ hour B. coli cultures on similar media. 

 Mild but definite illness followed in two cases after the injection 

 of filtered washings of 5}^-hour cultures of the Flexner bacillus 

 on hormone agar. 



In a few isolated experiments we failed to obtain any indica- 

 tions of the formation of the poisonous substances with staphylo- 

 coccus and pneumococcus, Type I. 



All attempts to establish specificity or non-specificity in im- 

 munological experiment by treating rabbits with filtrates of the 



