246 THE BACTERIOPHAGE 



Experiment V. This test was conducted with the assistance 

 of Dr. Ormieres at Carcassonne. 



The epizootic began during the month of August. By October 1, 80 

 chickens had succumbed. The 120 survivors were immunized. The 

 epizootic stopped immediately and no further cases appeared after the 

 date of the immunization. 



Experiment VI. This experiment was conducted with the 

 assistance of M. Mesnard, Departmental Veterinarian at Angou- 

 l&ne. In these experiments the chickens were immunized by 

 the ingestion, on bread, of about 1 cc. of an antigallinarum 

 bacteriophage. 



A. On July 2 the 50 chickens surviving in a poultry-yard where typhosis 

 had been prevalent for six weeks, with a daily mortality of 2 or 3 fowls, 

 each ingested about 1 cc. of the bacteriophage culture. Seven months 

 later no new case had developed since the time of the ingestion. 



B. The same test was performed on October 15 on about 100 chickens on a 

 neighboring farm where typhosis had been present fro several months. 

 The epizootic was immediately and completely checked. 



In both of these cases the disease continued to spread throughout the 

 neighboring poultry-yards that were held as controls. 



It appears needless to multiply such examples. In all cases 

 the picture has been the same. The epizootic disappeared from 

 the time that the culture of bacteriophage virulent for the patho- 

 genic bacterium, the cause of the epizootic, had been introduced 

 into the organism of the susceptible animal, whether this was 

 brought about by injection or ingestion. We will see later that 

 this last mode of administration is somewhat less efficient than 

 injection. 



On the contrary, injections of cultures of a bacteriophage 

 active for B. gallinarum, the specific cause of typhosis, had in 

 general, no effect when the epizootic was a paratyphosis, par- 

 ticularly in the case of infections due to B. pfaffii. In practise, 

 it is only necessary to inject a mixture of different strains of 

 bacteriophage active for the various pathogenic bacteria that 

 may produce the epizootic. This mixture should also include a 

 strain active for chicken cholera. It will be very easy to accom- 

 plish this, for the dose of 0.5 cc. which I have arbitrarily adopted 



