When bacteriophage is precipitated by alcohol at room temperature its activity rapidly and progressively decreases until it is totally destroyed, between 6 and 24 hours after exposure.
If the percipitation is carried out at 7°C. the destruction of lytic activity is considerably slower; measurable traces may be detected even after 4 weeks exposure to alcohol. Although the major portion of the lytic activity is found in the precipitate, the supernatant alcohol carries a measurable amount of lytic principle which remains active for several days.
In all cases the residual lytic activity was found to be transmissible in series. In no instance were we able to observe the non-transmissible action ascribed by d'sHérelle to the enzyme.
The persistence of traces of active principle after many weeks of exposure to alcohol at low temperature is not found to be due to the existence in the original filtrate of a fraction relatively resistant to the effect of alcohol.
The inactivation of bacteriophage by alcohol seems, therefore, analogous to the alcoholic inactivation of certain enzymes and toxins.