126 



BACTERIOLOGY 



then pushed into the tube about i centimeter. Now allow a 

 watery solution of pyrogallic acid to run into the plug, and then a 

 watery solution of sodium or potassium hydroxide. Close 

 quickly and tightly with a rubber stopper. Wright recommends 

 that the first solution be freshly made and consist of about equal 



volumes of pyrogallic acid and water, 

 and that the second solution contain i 

 part of sodium hydroxide and 2 parts 

 of water. With 6 inch test-tubes, f 

 inch diameter, the amounts advised are 

 \ c.c. solution of pyrogallic acid and 

 i c.c. solution of sodium hydroxide. 



Hydrogen Atmosphere. The most 

 perfect anaerobic conditions are ob- 

 tained by replacing the air with hy- 

 drogen in a perfectly air-tight container. 

 The method of hermetically sealing such 

 containers full of hydrogen by melting 

 the glass in a flame is really too dan- 

 gerous to be recommended. The ap- 

 paratus devised by Novy is most con- 

 venient and has practically superseded 

 all other devices for cultivation of 

 anaerobes in hydrogen. The Novy jar 

 is especially valuable for plate cultures. 

 In using this jar, all ground-glass sur- 

 faces should be thoroughly coated with 

 a fairly stiff mixture of bees wax and 

 olive oil so as to make all joints air-tight. Rubber gascots or 

 packing should never be employed between the ground-glass sur- 

 faces, regardless of the fact that many dealers furnish them for this 

 purpose. After the plate cultures or tubes have been put into the 

 lower section of the jar, the cover is put on so that the flanges fit to- 

 gether perfectly. A heavy rubber band may then be passed around 

 the circumference of the flanges to cover the circle of contact. Fi- 



FIG. 52. Arrangement of 

 tubes for cultivation of anae- 

 robes by Buchner's method. 





