238 SCIENCE PROGRESS. 



alone, with inoculations of either bacillus anthracis, bacillus 

 tuberculosis, or bacillus mallei, and thirdly with doses of 

 phloridzin and inoculations of these bacilli. The experi- 

 ments with anthrax and tubercle were negative ; but of 

 white mice treated with phloridzin by the mouth and 

 intraperitoneal injections of bacillus mallei forty-seven out 

 of forty-nine individuals died within three to nine days, and 

 among" forty-eight mice treated with phloridzin alone, none 

 succumbed. The conclusions drawn from these experiments 

 are that the blood of white mice contains a bactericidal 

 substance and this power is injured by the presence of 

 sugar or of phloridzin in the blood. Charrin and Roger (i 8), 

 working on the well-known immunity presented by rats to 

 anthrax, have also shown that fatigue is capable of inducing 

 susceptibility. Like fatigue, currents of cold air will pro- 

 foundly affect the metabolism of the body (19), and in the 

 case of rabbits and guinea-pigs these agents increased the 

 natural susceptibility to anthrax. Feeding- these animals on 

 liquid food also augmented their susceptibility (20). The 

 normal resistance of rats to anthrax is stated by Feser to 

 be considerably weakened when these animals are fed on 

 a vegetarian diet, and Hankin (21) has confirmed these 

 results, using groups of animals which fed on meat and 

 bread, and on bread alone; in the latter case the susceptibility 

 was induced and the spleens of these animals contained 

 only traces of defensive proteid, while the spleens of the 

 first group yielded abundance of this substance. 



The necessity of the vital concurrence of micro-organisms 

 for the production of infective diseases has long been a theo- 

 retical conception, and with regard to the infection by bacil- 

 lus maligni cedematis and bacillus tetani this appears to be 

 verified. It has been shown that the pathogenic properties 

 of the former are not marked, owing to non-development, 

 unless some of the culture material is also introduced, or if 

 there is an admixture of the proteus vulgaris or micro- 

 coccus prodigiosus. Under these circumstances both the 

 non-pathogenic and pathogenic microbes develop, and an 

 active infection with characteristic symptoms of oedema and 

 gas formation at the place of injection occurs. Further,, 



