REACTIVITY TO VARIOUS MICROORGANISMS 5I 



tain the reactions by the use of a pneumococciis filtrate ^vhen the 

 cells were not disintegrated. In a limited ntmiber of experiments, 

 it appeared to these authors that specificity of the pneumococciis 

 could be demonstrated by means of the phenomenon. In 44.4 per 

 cent of the experiments, prepared sites reacted only to the intra- 

 venous injection of homologous preparations. In 13.8 per cent of 

 the experiments, positive reactions were obtained with combined 

 intradermal intravenous injections of heterologous types of pneu- 

 mococci. 



In my investigations of 1931-1932 additional attempts were 

 made to obtain the pneumococciis acti\e principles from aerobic 

 and fully and j)artially anaerobic fluid cultures of \'arioiis hydro- 

 gen-ion concentrations and containing various sugars and other 

 enriching substances (Shwartzman, 1932/) . 



The experiments may be summarized as follows: 



The ^ariolls preparations employed ^vere totally devoid of skin- 

 preparatory factors inasmuch as reactions were not obtained when 

 pneumococciis preparations were used for the skin injections. 

 The phenomenon could be elicited, however, when rabbits were 

 prepared ^vith B. typhosus "agar washings" filtrates of high skin- 

 preparatory potency and pneumococcus filtrates were injected in- 

 travenously. The experiments thus demonstrated that it is pos- 

 sible to obtain pneumococciis filtrates potent in reacting factors. 



Most of the work was done with pneumococciis Type III 

 strains. Fairly consistently potent preparations were obtained 

 under the following conditions: 



In the late afternoon pneumococciis Type III was seeded into 

 100 c.c. of meat infusion broth, pH 7.8, containing 0.2 per cent 

 glucose and 0.3 per cent maltose. The container was an Erlen- 

 meyer flask of 200 c.c. capacity (partial anaerobiosis) . The cul- 

 ture was incubated at 37° c. until the following day, when the 

 pH was adjusted to 7.8 and 0.2 per cent glucose and 0.3 per cent 

 maltose were added again. This was repeated for three consecu- 

 tive days. After the last readjustment of pH, the culture was in- 

 cubated for one more day and after this centrifuged until the 

 supernatant fluid became clear. The supernatant fluid ^vas fil- 

 tered through a Berkefeld "\'" candle. The rabbits prepared by 

 the intradermal injection of 0.25 c.c. of a heterologous potent 

 bacterial filtrate reacted to the intravenous injection of 1 to 2 

 c.c. ])er kilo of body ^veight of the pneumococciis filtrate. Type I 

 pneumococcus culture filtrates made in the above manner proved 



