522 Messrs. W. E. Bullock and W. Cramer. On a New 



Vihrion septique, obtained by inoculating meat broth with fragments of 

 breast muscle from pigeons which had been inoculated four hours previously 

 with a broth culture of these organisms to which calcium chloride had been: 

 added, was not more virulent than a culture from a pigeon which had been 

 infected with broth cultures alone of these bacteria. 



It is clear, therefore, that the action of calcium chloride is not due to a 

 change in the essential properties of the bacteria so as to make them 

 individually more virulent. This conclusion is confirmed by the observation,, 

 to which reference has already been made, that a direct contact between the 

 bacteria and calcium salts is not essential for the production of the kataphy- 

 lactic effect. There remains the other alternative, that the effect of calcium 

 salts might be to make the animals more sensitive to the action of the 

 bacteria. Now it is known that the bacteria of gas gangrene and of tetanus 

 owe their pathogenic effect to the formation of a toxin. The correctness of 

 the second alternative can therefore be tested by determining whether the 

 injection of calcium chloride diminishes the minimal lethal dose of these 

 toxins. This test was applied to the toxin of B. Welchii. It was found that 

 the injection of calcium salts did not make an animal more sensitive to the 

 action of this toxin. What, then, is the explanation of the phenomenon 

 described in this paper if it cannot be attributed either to an increased 

 sensitiveness of the infected animal or to an increased virulence on the part 

 of the infecting bacteria ? A partial answer to this question is given by the 

 experiments, in which the injections of calcium salts and of bacteria were 

 separated in time or in space. 



Gas gangrene will result if Vihrion septique spores are injected into an 

 animal which some hours or days previously has received an injection of 

 calcium salts. This result is obtained, most readily if the two materials are 

 injected into the same site, and in that case the interval between the two 

 injections may extend over several days if a large dose of calcium salt has 

 been given. Thus in two different experiments the following results were 

 obtained : 2 '6 mgrm. Ca salt given two hours before Vihrion septique spores : 

 injected into same site into eight mice. Result. — All mice dead within 

 24 hours. 10 mgrm. Oa salt given three days before Vihrion septique spores : 

 injected into same site into nine mice. Result. — All mice dead within 

 24 hours. Even if the two materials are inoculated in two different sites, 

 gas gangrene may follow, although not in every case. 



The following experiment may be given to illustrate the result of 

 separating the sites and times of injecting the bacteria and the rupturing 

 substance. In this experiment 36 mice, in 12 batches of 3 mice each, 

 received at the same time injections of calcium nitrate in varying doses. 



