40 THE AMERICAN MONTHLY [Jan. 



had at last got them separated prevented my being ready with 

 more than the above very incomplete observations as to these 

 last two kinds. They are now, as will be seen, well differenti- 

 ated in the tubes shown, and are ready for further investigation. 



The hanging drop cultures, one of each of the three kinds 

 shown herewith, are taken from the respective tubes, and are 

 about 24 hours old. 



The media have all been slightly alkaline. Trials were made 

 on agar and gelatine media, in which fish was used instead of 

 meat, but without any difference in the result. — Walter P. 

 Shvdbolt in " Journal of the Queckett Micros. Club." 



BACTERIOLOGY. 



Staining Bacillus Tuberculosis in Milk, — While milk is 

 one of the most common sources of infection in typhoid and 

 tuberculosis, from its composition, unfortunately, it is very dif- 

 ficult to demonstrate the presence of these micro-organisms in 

 any given sample. May's process of precipitation of the casein 

 is very unsatisfactory, and in lieu thereof a writer in the Moni- 

 tore de Farmacisti suggests saponification of the fat globules by 

 the following process : A drop of milk is placed on a glass slip 

 and two or three times its volume of a 1-per-cent solution of 

 sodium carbonate is added, and the fluids mixed with the aid 

 of a plantinum wire. The slip is then cautiously held over the 

 flame of an alcohol lamp and the liquid slowly evaporated to 

 dryness. During the evaporation the butter particles are sap- 

 onified, leaving a thin layer of dessicated soap on the slip. 

 The subsequent treatment is identical with the usual process 

 (staining with fachsin, etc.)- Rapid coloration with intense ao- 

 lutions is preferable to the slower methods. 



