PROPERTIES OF THE BACTERIOPHAGE 283 



digestion. In a more recent communication*'^*' he admits that the 

 destruction is only partial, and that it is more or less complete depending 

 on the race of the bacteriophage used. 



With reference to the many publications, announcing the discovery 

 of the bacteriophage in enzyme-containing products, a subject to which 

 we will return, I have performed a variety of experiments to determine 

 the nature of the action of papaine and of trypsin on the bacteriophage. 

 I have never been able to find any manifest changes when a suspension 

 of one or the other of these ferments was combined with the bacterio- 

 phage. On the contrary, when I mixed trypsin or papaine with a 

 bacterial suspension inoculated with the bacteriophage, I observed a 

 very sharp inhibition, but, in view of the former experiments, I am not 

 able to attribute this inhibition to a destruction of the corpuscles by the 

 ferment, but rather to an action of the ferment on the bacterium, an 

 action which interferes with bacteriophagy. Among other experiments 

 having a similar significance, we will see that an antibacterial serum 

 has no action whatever upon the bacteriophage, but that it exercises an 

 inhibitory action upon bacteriophagy with the homologous bacterium. 

 The surface of the bacterial body must be modified in some way, both 

 by the antiserum and by the proteolytic enzymes, so that it is not sus- 

 ceptible to the adhesion of the bacteriophage corpuscles. It may be 

 mentioned, however, that in any case the inhibition is relative only; 

 bacteriophagy is retarded but it still takes place. 



2. CONSERVATION OF THE BACTERIOPHAGE CORPUSCLE 



Before undertaking an analysis of this phase of the subject of bac- 

 teriophagy it may be well to call attention to a very important point, 

 which applies as well to the effect of the passage of time as to that of 

 any agent, physical or chemical. We find that a suspension of the 

 bacteriophage contains a number of corpuscles which we may designate 

 as "x." We subject this suspension to the action of any agent whatso- 

 ever and when the action is completed we find, for example, that the 

 number of corpuscles has become x/10. We conclude immediately that 

 9/10 of the corpuscles have been destroyed. Is this deduction beyond 

 question legitimate? By no means. We can detect the bacteriophage 

 only because of the fact that it causes bacteriophagy, that is, we detect 

 its 'Virulence." Death of the corpuscle or the loss of its virulence would 

 lead to the same effect, the absence of bacteriophagy. Let us observe 

 that through the action of time, through increases in temperature, or 



