ENDOTOXIN. 



125 



On close study of the above experiment, it will be noted that even in those 

 cases in which the animals died of the infection, bacteriolytic phenomena 

 were not altogether absent. They occurred particularly in the beginning 

 and were incomplete. This can be considered as evidence of the fact that 

 even normal animals possess a certain supply of bacteriolysins which are, 

 however, readily exhausted. This amount of normal bacteriolysin in serum 

 varies greatly with the species of animal; thus the sera of man and rabbit 

 contain very little normal bacteriolysins for cholera and typhoid, while 

 horse's serum is well supplied with the same. 



According to Kolle, a loopful of virulent cholera vibrios is destroyed in the peritoneal 

 cavity of a guinea-pig, by 



0.005 to o.oi c.c. of normal horse's serum, 

 o.oi to 0.02 c.c. of normal ass serum, 

 o 02 to 0.03 c.c. of normal goat's serum, 

 o.i to 0.3 c.c. of normal rabbit's serum. 



The protective action of bacteriolytic sera differs very essentially from 



that of antitoxic sera. For the latter, the law of multiple proportions holds 



true; a stronger dose of toxin is neutralized by a proportionately larger 



amount of antitoxin; to bacteriolytic sera this rule does not 



Endotoxin. apply. If the bacteria are increased beyond a certain quantity, 



their dissolution can indeed be accomplished by the addition of 



sufficient amounts of (bacteriolysin), but the animal dies nevertheless. Its 



peritoneal cavity examined during life or post-mortem may be absolutely 



sterile. Pfeiffer's explanation for this phenomenon is that the endotoxins 



within the bacteria are liberated by bacteriolysis and kill the animal. Fatal 



results from endotoxin follow in a similar manner when dead instead of 



living bacteria are injected. 



Since endotoxins can continue their effective action in spite of the serum, 

 it is evident that the usual bacteriolytic serum lacks the power to neutralize 

 the poisons of the endotoxins. Many investigators have attempted to sup- 

 ply this deficiency. (This will be considered later). 



While bacteriolysis may take place without any resulting protective action, 

 on the other hand a serum may be curative in spite of the absence of bacterio- 

 lysis. This is well demonstrated in Metschnikoff's experiment. 



A marked leucocytosis in the abdominal cavity of a guinea-pig 

 Metschnikoff's is produced by the intraperitoneal injection twelve hours 

 Experiment, previously of 5 to 10 c.c. of aleuronat solution or sterile 

 bouillon. Pfeiffer's experiment is then performed. As a rule, 

 bacteriolysis occurs also here up to a certain point, particularly when chol- 

 era vibrios are used; most of the bacteria, however, retain their form and 

 are taken up by the leucocytes. 



Metschnikoff used this experiment to uphold his theory of the signifi- 



