IMMUNIZATION WITH BACTERIOPHAGE SUSPENSIONS 511 



zootic in Vienna, it had not then been incriminated as capable of pro- 

 ducing disease in the Galhnaceae. These facts have only been dis- 

 closed gradually in the course of these investigations. 



The suspensions of bacteriophage used in the immunization experi- 

 ments were prepared in the following manner: 



A culture of B. gallinarum, in Martin bouillon, aged nine or ten 

 hours, that is, very young but showing a definite turbidity, is inocu- 

 lated with a bacteriophage isolated from the excreta of a recovered 

 chicken and possessing a high virulence for the pathogenic bacillus. 

 After about 12 hours the bacterial dissolution is completely finished and 

 the bouillon is perfectly limpid. This material is filtered through a 

 bougie and distributed into ampoules which are sealed. 



The dose employed for immunization has been in all cases 0.5 cc, 

 given subcutaneously. The point of injection is of no importance for 

 the slightest local or general reaction has never been observed. 



Experiment I. The following experiments were conducted in 1919 

 and 1920 in the neighborhood of Agen with the assistance of M. Lam- 

 bert, D.V.M. 



Barnyard 1. The epizootic began in August, 1919. By October 2, 

 110 of 160 fowls had died. The 50 survivors, of which 5 were already 

 affected were inoculated with the bacteriophage. The 5 sick chickens 

 recovered and the epizootic stopped abruptly and definitely on the 

 same day as the immunization. 



Barnyard 2. The epizootic began about August 20. By October 6, 

 120 of 200 fowls had died. The 80 survivors, of which 7 were sick, 

 received an injection of the Gallinarum-bacteriophage. The 7 re- 

 covered; the epizootic immediately and permanently disappeared. 



Barnyard 3. The epizootic began October 10. By the 15th, 21 

 fowls had died. The 130 that were ahve, of which 8 were alread}^ sick, 

 were inoculated. The 8 recovered and the epizootic disappeared 

 from the day of the inoculation. 



Barnyard 4. The epizootic began about November 15. By Decem- 

 ber 1, 26 of 51 fowls were dead. The 25 survivors, among which were 

 4 which were infected, were inoculated. One of the sick animals died, 

 the other 3 recovered. The mortahty stopped from the date of the 

 inoculation. 



Barnyard 5. The epizootic began about November 25. By Decem- 

 ber 1, 7 of 60 chickens had succumbed. The 53 survivors were in- 

 oculated. Of these 4 were sick. The sick animals recovered and no 

 new cases appeared. 



