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



latter are injected after an interval of 20 hours into the same site. When 

 different sites are used, however, the production of gas gangrene becomes 

 more difficult, and it is necessary to use larger doses of the calcium salt and 

 to inject tlie spores within a short time after the calcium salts. Post-mortem, 

 examinations were made of one dead mouse in each batch. All showed the 

 typical lesion of Vih^ion septique gas gangrene in the right flank, and this 

 was the case even in the three mice where the spores had been injected on 

 the back. Only one of these three mice had the typical lesion also on the 

 back ; the two others only showed a slight serous exudate, such as is found 

 in normal mice after the injection of spores. This remarkable fact will be 

 referred to again below. 



Similar experiments were carried out with a suspension of B. Welchii. 

 With these bacteria the dose of calcium salt has to be increased to 5 mgrm. 

 if an interval of time is allowed to elapse before the injection of the 

 bacteria, and this interval of time within which gas gangrene can be 

 produced is limited to a few hours. After an interval of 24 hours, we 

 have not been able to produce gas gangrene even with a dose of 10 mgrm. of 

 calcium salt. Doses of 10 mgrm. of calcium salt are necessary when 

 different sites are used. Under these conditions, we have observed two 

 diff'erent courses which the infection may take. Either, as in the case of 

 Vih'ion septiqite, the typical lesion of B. Welchii gas gangrene is produced 

 at the site of injection of the calcium salt, and may be completely absent 

 from the site where the bacterial suspension was introduced ; or there is no 

 distinct localised gas gangrene lesion, but a B. Welchii septicaemia results, in 

 which the hsemolytic action of the infection seems to predominate. Eor in 

 such animals B. Welchii can be seen in fi^lms made from the heart blood, the 

 liver and kidney are very pale instead of showing the intense congestion of a 

 typical B. Welchii gas gangrene, and the blood is very poor in hemoglobin. 



Experiments with spores of B. tetani (Type II of Dr. Tulloch) gave 

 essentially the same results as those with B. Welchii and the spores of 

 Vibrion septique. As the Table shows, it was possible to elicit tetanus by 

 injecting the spores 2| hours after the injection of even the minimal 

 rupturing dose of the calcium salt, when the spores were injected into 

 the same site as the calcium salt. But, when different sites were used, 

 tetanus did not occur even with the biggest dose of calcium salt used. Even 

 with an interval of 24 hours tetanus was produced, but then it was delayed 

 and occurred only with larger doses of calcium salt and using the same site. 

 It must be noted, however, that for the experiments with a 24-hours' 

 interval, a different and older preparation of spores was used, which 

 appeared to have lost some of its virulence, since the spores did not 



