424 INFECTION AND RESISTANCE 



(antigenic) proteins. We have not been able as yet to study the 

 matter extensively, but we have carried out a few experiments. 



Typhoid bacilli from twenty-four agar cultures were weighed as 

 a moist mass, ground up with salt, and then taken up in distilled 

 water to isotonicity. After the addition of 0.2 c.c. of N sodium 

 hydroxid to 100 c.c. the suspension was heated to 60 C. for 30 

 minutes to prevent autolysis, and was then shaken for 4 to 5 hours 

 with a motor, at room temperature. After filtration through a 

 Berkefeld candle the clear solution gave a definite cloud after boiling 

 and adding acetic acid. The filtrate was treated with heat and acid 

 to remove coagulable protein. On the advice of Professor Gies the 

 suspension was first brought to a boil and then small amounts of 

 acid were added to prevent possible hydrolysis which might have oc- 

 curred had the acid been added first. The filtrate from this was 

 then half saturated with ammonium sulphate. Again a definite cloud 

 was obtained, and when this was filtered clear, a second turbidity 

 could be produced by complete saturation with the sulphate. 



Although we have not yet obtained toxic reactions with these 

 substances after isolation, perhaps because of the difficulty of obtain- 

 ing them in sufficient amount, the presence of albumoses, substances 

 which have often been found to possess primary toxicity for animals, 

 suggests the possibility that their existence in the bacterial body 

 might indeed contribute to the injury done by injections of bacteria. 

 We found albumoses in extracts of typhoid bacilli not only when 

 the bacteria were grown on the ordinary peptone media but also on 

 agar made without peptone to which nutrose or sodium casemate has 

 been added as an enriching substance. 



Moreover, we have also had the experience with the typhoid 

 bacillus which is referred to repeatedly by Vaughan when dealing 

 with the colon bacillus ; namely, that bacterial suspensions sub- 

 jected to boiling are quite as toxic and often more so than are the 

 unheated and living suspensions. 



Thus, if three guinea pigs are injected with equal amounts of 

 typhoid suspensions, one with the living bacteria, the second with 

 bacteria heated to 60 C. for 15 minutes, and the third with bacteria 

 boiled for 5 minutes, the guinea pig receiving the boiled bacilli will 

 often be the first one to grow sick and die several hours before the 

 others. 



This may mean, of course, as Vaughan suggests, that the heated 

 protein is more promptly split by the ferments of the body. It 

 also suggests, however, that in addition to this the heating has left 

 unchanged non-coagulable toxic constituents of the cell. 



It still remains for us to consider certain experimental facts 

 which have had some influence upon extending and altering the con- 

 ceptions of anaphylatoxin formation which we have just outlined. 



