1883.] On the Infectivity of the Blood and other Fluids. 463 



species found ; whereas in cases of infection with this specific form of 

 Davaine's septichaemia, the particular bacterium increases within 

 certainly fifteen hours, so as to outnumber many times the red blood- 

 corpuscles, here none were to be found in a materially longer period. 

 Hence it seems to me to be clear that the specific bacterium of Davaine's 

 septicha3mia does not normally exist in the blood of healthy rabbits. 

 Numerous preparations of blood from different parts were made, 

 stained, and carefully examined, with the same result in all. 



The experiment was repeated with a guinea-pig, similarly killed 

 and kept in the incubator for twenty-four hours, at the end of which 

 time it was enormously distended with fetid gases, the blood from the 

 heart and principal organs also contained a Bacillus in some numbers ; 

 this was similar in form to that found in the case of the rabbit, but 

 somewhat less in size, and spore formation was more advanced. To all 

 appearances it is identically the same as that which developes in cases 

 of peritonitis or the so-called Pasteur's septichaemia in the guinea-pig. 

 Whether or not it is specifically identical with the Bacillus that 

 developes in dead healthy rabbits or in septic diseases in that animal, 

 can only be determined by interchanging inoculations or cultivations 

 of each growth, for though there is a slight morphological difference 

 in the organisms of the two animals, it is clearly the fact that the 

 same species of Bacillus, growing in different media, varies appreciably 

 in its dimensions, as is typically exemplified in the case of the Bacillus 

 of Anthrax. 



Artificial Cultivation. 



In the first trials of cultivating the organisms here in question in 

 open tubes, both those of Davaine's and the so-called Pasteur's 

 septichaemia, I failed to obtain conclusive results with any of the 

 nutrient fluids employed, infusions of the flesh of different animals, and 

 with blood serum : in the latter the bacteria of Davaine's septichaemia 

 germinated, producing a turbidity which extended very slowly and to 

 small extent, dying out generally after about the second day ; the 

 serum used being partially solidified by evaporation in prolonged 

 heating, though still perfectly pellucid and not in any way coagulated. 

 The Bacilli in the other case behaved in much the same manner in 

 different fluids. 



In the last experiments made during the winter, as I failed to again 

 originate specific infection with Davaine's septichaemia by inocula- 

 tion with putrid blood, I have been unable to repeat the attempt to 

 cultivate these organisms. As, however, it has been stated that the 

 microphyte of Pasteur's septichaemia has been successfully cultivated 

 in vacuo in France, and it seemed probable, from the conditions under 

 which it occurs in the animal organism, that it would thrive best in 

 the absence of oxygen or atmospheric air, the experiments were 



