TEXT-BOOK OF BACTERIOLOGY. 343 



Hog- erysipelas is one of those diseases in which Pasteur has 

 succeeded in producing- artificial immunity by inoculating with 

 attenuated poison. He has also two " vaccins," one of them being 

 altogether harmless ("premier"), and a stronger one ("deuxieme") 

 which is said to be applied twelve days after the first and to surely 

 protect the animals against the plague. Schtitz has shown that 

 Pasteur's inoculating matter contained, in fact, the bacilli of hog 

 erysipelas. He tested the efficiency of the French "vaccin" and 

 found that .it renders the tiogs immune; he has finally been able, 

 under the influence of high temperatures, to obtain attenuated de- 

 scendants from vigorous bacilli, these descendants possessing the 

 same properties as Pasteur's inoculating matter. 



Veterinary surgeons have long known that hogs are protected 

 against a second attack of the disease after they had recovered 

 from the first attack of erysipelas. But most of them express them- 

 selves with reserve regarding the practical value of protective inoc- 

 ulation. The " deuxieme vaccin " is by many charged with affecting 

 the animals with chronic hog erysipelas and giving rise to an unin- 

 tended and exceedingly dangerous, permanent spread of the bac- 

 teria. Additional investigations will determine the correctness of 

 this assertion. 



XXXI. MOUSE-SEPTIC^MIA BACILLUS. 



The bacilli of hog erysipelas greatly resemble, in their growth 

 upon solid media, and in their action on various animal species, the 

 bacilli of mouse septicaemia, first observed by Koch and more fully 

 described in 1878. 



Koch found, by inoculating domestic or white mice with putre- 

 fying fluids (especially blood), that a certain number of the animals 

 perished, and there could be detected in the blood and in all the 

 organs quantities of exceedingly fine rods successfully transmissible 

 to healthy mice. 



An exact description of the bacilli of mouse septicaemia would 

 necessitate almost a repetition of what has been said in reference to 

 the erysipelas bacilli and we will merely call attention to the differ- 

 ences undoubtly existing between the two micro-organims. 



The bacilli of mouse septicaemia are generally somewhat nar- 

 rower and thinner than those of erysipelas; they seem to be in- 

 capable of voluntary motion ; roundish and shining corpuscles often 

 appear in the interior of the rods, which are regarded as spores. 



They belong to those bacteria which thrive as well, perhaps 

 better, in the absence of oxygen as with a free access of air and 

 can, therefore, be numbered among the semi-anaerobic species. 



