Cholera Suis, Hog Cholera, ete. 45 



Recovered cases after the disease caused by a pure culture of hog 

 cholera bacillus do not show such immunity. It would appear, 

 therefore, as if the hog cholera bacillus were an attendant com- 

 plication, though by no means a harmless one, whilst the pri- 

 mary infecting factor is the, as yet unseen, infinitesimal organism. 



Of 21 pigs herded with pigs that had been injected subcutem 

 with /'Mrs cultures of Bacillus Cholera Suis, only one showed any 

 sickness, and that very slight. The blood of the injected pig to 

 which this was exposed, though injected intravenously into a 

 healthy pig, had no ill effect, showing the absence of both the 

 B. Cholerm Suis and the unseen infinitesimal organism. The 

 one which had slight sickness, when afterward penned with casual 

 cases of hog cholera, proved immune. 



Eighteen of the above 21 pigs, exposed to swine injected with 

 pure cultures of the Bacillus Cholerse Suis, were afterward put in 

 a pen with cases of casual hog cholera and 16 sickened. The 

 rate of mortality in these 16 is not mentioned. The two other 

 pigs were evidently immune. One had shown slight illness as 

 named above, when exposed to hogs injected with pure cultures 

 of Bacillus CholercB Suis, and both resisted infection when 

 penned with hogs suffering from casual hog cholera. 



Of II pigs, injected subcutem, with blood from hogs sick from 

 administration of pure Cultures of B. Cholerce Suis, none sick- 

 ened, and of 10 of these, exposed to infection in a pen with casual 

 cases, 9 sickened and 7 died. 



Of 19 pigs injected subcutem ^iih. pure Cultures of B. Cholerce 

 Suis, 3 only died and 8 showed no illness. Of 2 fed with the 

 same B. Cholerce Suis in pure cultures, both sickened and recov- 

 ered. Of the 18 survivors, placed in a pen with casual hog chol- 

 era cases, 16 sickened and died. Six of these had already shown 

 sickness from injections of pure cultures and 2 from being fed on 

 them, while 8 had shown no illness as the result of these cul- 

 tures. The 2 survivors had both sickened from injections of the 

 pure cultures. 



Two sound pigs injected subcutem with blood from a case of 

 casual hog cholera, and the blood taken at intervals from the tail, 

 and in each instance disposed of, ist by injecting a sound hog sub- 

 cutem, and 2d by culture in neutral bouillon, it transpired that 

 blood proved infecting to the two hogs on the second day, while 

 the bouillon was not successfully inoculated with the B. Cholerce 



