CULTIVATION OF ANAEROBIC BACTERIA. 



77 



Hesse covers the surface of the inoculated medium with 

 sterile olive oil, more effectively to exclude oxygen. 



Smith fills the tube with sterile gelatin, thus burying the 

 culture. He uses an ordinary fermentation-tube for this pur- 

 pose. A test-tube answers as well. 



Liborius expels the air from the tube and medium by 

 boiling. The liquid medium is inoculated and then hard- 

 ened in ice water. The tube (Fig. 29) is sealed with the 

 blowpipe. 



FIG. 30. 



Fraenkel's method for the cultivation of anaerobic bacteria. 



Esmarch makes a roll culture, and then fills the tube with 

 sterile gelatin. 



Buchner absorbs the oxygen with pyrogalliG acid. 1 

 gram of pyrogallic acid and 10 c.c. of a 6 per cent, solution 

 of potassium hydroxide are placed in a large dissolving tube. 

 The tube containing the culture is stood inside of the large 

 tube, which then is corked and sealed with paraffin. 



