428 THE AMEHICAN MONTHLY [Dec 



and cloak were literally alive with them. To brush them 

 off was a matter of some time, and when my fellow trav- 

 eler at length thought himself free, he was dismayed to 

 find a mouse in each of his trouser pockets." Doubtless, 

 all bacteriologists are familiar with the experiments of 

 Loeffler, Lazare and Merezhkovski ; but it may not be 

 amiss to mention that, besides certain morphologic dis- 

 tinctions the differences between the bacillus typhi mu- 

 rium of Loeffler and the bacillus derived from mice by 

 Merezhkovski consist mainly in this, that the mice die 

 sooner when infected with Merezhkovski's bacillus than 

 with that of Loeffler. Experiments with the infection 

 of mice by means of Merezhkovski's bacillus were car- 

 ried out by himself in his laboratory. As regards the 

 typhi murium of Loeffler, besides the experiments of 

 exterminating mice in the fields carried out by Loeffler 

 himself in Greece, similar experiments were made by 

 several E,ussian laboratories, among others, by that of 

 the Odessa bacteriologic station in the provinces of Cher- 

 son and Podolia. These experiments were made in the 

 fields and in the places where there was grain in stacks, 

 and gave satisfactory results. These cultures of Loe- 

 ffler's bacteria are customarily sent out in tubes of agar- 

 agar, where they retain their vitality during the course 

 of several months. The contagium of typhi murium pre- 

 sents itself in the shape of a gray film on the slanting 

 surface of the jelly in testing tubes. For the purpose 

 of using it, the film must be mixed with water in which 

 pieces of white bread are soaked ; the transparent remain- 

 der of the contents of the tube must be distributed, to- 

 gether with the pieces of bread, in the localities where the 

 mice prevail. The details of this manipulation are as 

 follows : 



1. A .5 per cent, solution of table salt in water (one 

 teaspoonful of salt is taken for five glasses of water) is 



