1893.] MICROSCOPICAL JOURNAL. 177 



character, the projected image being seen throiigh it, consists 

 of several sectors, mounted step-like in several different planes 

 normal to a common axis of revolution. The projected image 

 may occupy about one-sixth of the area of the screen, near to its 

 edge. The screen may be rotated by an air-jet acting on vanes 

 "or any of the other motors used for zoetropes." — The Op- 

 tician. 



BACTERIOLOGl. 



Savelieff's Method of Preserving and Examining Spu- 

 tum for Tubercle-bacilli. — The object of this process is to pre- 

 serve the sputum until examined. In 1890 Savelieff (a Russian 

 investigator) suggested a very convenient method for preserving 

 the sputum and examining it bacteriologically at a more or less 

 remote date after its expectoration. It consists in having the 

 patient expectorate in a dish containing 95 per cent, alcohol, in 

 which medium the discharge can remain for several months. As 

 the sputum is hardened in the alcohol (through dehydration and 

 coagulation), Savelieff liquefied the coagulated sputum with a 

 solution of caustic potash prior to making the cover-glass prepa- 

 rations. The technique employed was to remove a small lump 

 of the coagulum, place it upon a slide, and add a few drops of 

 caustic potash solution, which reduced the coagulum in a very few 

 minutes to a more or less pasty consistency, from which the prep- 

 arations were made. After drying, they were rinsed in water, to 

 remove the potash, and stained. The film was fixed by passing 

 the cover-glass three times through the flame of an alcohol lamp 

 or Bunsen burner. Thus prepared, the preparation was stained 

 by some familiar method. 



Yeasts and Bacteria of Natural and Artificial Wines. — 

 MM. Schaffer and von Freudenreich have reported on the micro- 

 organisms existing in natural and artificial wines, and, consider- 

 ing the method of manufacturing and composition of these latter, 

 the authors' results are not surprising. 



Of the ten natural wines examined only one contained bacteria, 

 and this one, from imperfect treatment, had always been cloudy. 

 Wines which had been several years in bottle were sterile, con- 

 taining neither yeast nor bacteria. Artificial wines contained 

 numerous bacteria, and the authors throw out the suggestion that 

 the presence of these bacteria may have some connection with 

 gastric disorders. — your. Royal Micr. Society. 



The Bacteriology of Tobacco. — In the process of " sweat- 

 ing," during which are formed many of the aromatic compounds 

 upon which the flavor of tobacco depends, the result varies 

 greatly with the kind of bacteria which take the chief part in 

 the fermentation. German growers of tobacco have tried in vain 

 to improve the quality of their crop by enriching the soil and by 



