576 THE BACTERIOPHAGE AND ITS BEHAVIOR 



immediately after this removal to inject the suspension of bacterio- 

 phage. Needless to say, the bacteriophage injected should be of maximum, 

 or at least very high (+ + + + ) virulence. 



If the temperature shows a progressive fall after this initial injection 

 I would advise that no further treatment be given. But if the tem- 

 perature still remains high on the day following the first treatment, a 

 second injection should be given, and, if necessary, a third on the next 

 day. If, as was the situation in Case 4 reported above, after the tem- 

 perature shows an initial fall it again rises, make a second injection. 



If buboes are not present, as in the case of septicemic or pneumonic 

 plague, intravenous injection of the bacteriophage should be tried. 

 From the nature of the effects observed in the few patients which I have 

 treated it would seem that, aside from the bacteriophagy which occurs 

 in vivo due to the inoculated bacteriophage, the injection of the sus- 

 pension exerts an antitoxic effect. I have already called attention to 

 this same fact in connection with the injection of suspensions developed 

 at the expense of B. dysenteriae Shiga. 



9. APHTHOUS FEVER 



It may not be out of place to mention here the studies of Meier^^^ 

 on aphthous fever, although it has not been demonstrated that the 

 bacteriophage is definitely responsible for the results. 



Impressed by a number of resemblances between what I have de- 

 scribed in connection with immunity in barbone of the buffalo and what 

 he had observed in aphthous fever, Meier undertook the studies indi- 

 cated below. He procured some of the excreta from a cow which had 

 had aphthous fever and which appeared to be recovering and from this 

 he prepared a filtrate. A few cubic centimeters of this filtrate were 

 injected into cows which were already infected and definitely sick and 

 into other animals which presented suspicious symptoms of the disease. 

 The results were decisive — the sick animals recovered quickly, the 

 suspected ones failed to develop the disease. 



Furthermore, the curative effect showed the features of a serial action. 

 Thus, the sick cows inoculated with the initial filtrate derived from the 

 naturally convalescent animal recovered promptly (within a few hours 

 (4) in some cases). Twelve hours after the inoculation he collected 

 feces from these treated cows (incidentally, during this period the char- 

 acter of the feces had changed, both in consistency and in color) and 

 prepared fresh filtrates. These also had a curative effect, causing a 

 very prompt improvement in condition when injected into sick animals. 



