22 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



of students located in countries where the rate of exchange is un- 

 favorable have told me that it was impossible for them to make a study 

 of bacteriophagy because of the price of filter candles. We will see in 

 a moment, however, that even this difficulty can be circumvented. 



With regard to porosity the most useful candles are those which 

 correspond to the Chamberland L3 filters, which are impermeable to 



Fig. 1. Filter Assembled According to the Method of Martin 



all bacteria. But let me state once more and finally, that a candle 

 capable of heat sterilization and repeated use is perfectly suitable no 

 matter what the make. I simply mention the Chamberland as indi- 

 cating a type and because they are the filters which I have used here- 

 tofore. 



Another question having a certain practical importance is the arrange- 



