ANTITOXIC PROPERTIES OF ANTIBIOTICS 169 



tumor sizes and weights in treated and untreated groups of mice bear- 

 ing sarcoma, after a period of 48 hours of growth. The groups were 

 matched as to initial size of the tumors. The selective damage said to 

 be caused by penicillin to sarcoma cells as compared with normal cells 

 (156) was later shown (567) to be due not to the pure penicillin itself 

 but to some impurity present in crude penicillin preparations. 



The hemorrhagic effect upon the tumors is highly selective, being 

 characteristic of the sarcoma cells only and does not occur in normal 

 tissues, with a few minor and slight exceptions. The phenomena of 

 hemorrhage and necrosis are followed in some cases by a complete and 

 permanent regression of the tumor. The curative effects of such treat- 

 ments are still open to question, however (94). The same may be said 

 of the effect upon tumors of trypanosomes or of the "factors" produced 

 by them. 



The effect of penatin upon sarcoma has been tested and found to be 

 negative (113). 



ANTITOXIC PROPERTIES OF ANTIBIOTICS 



The ability of various microorganisms to destroy or neutralize bac- 

 terial toxins has been definitely established. The substance involved was 

 designated as an antidotic (759). It is produced by B. subtilis and P. 

 notatum; however, isolated penicillin had no such effect, although 

 large doses of this antibiotic protected mice against the action of gono- 

 coccal endotoxin (685). Clavacin was also found (675) capable of neu- 

 tralizing tetanus toxin. 



