136 



SACTERIOLOGY 



part of sodium hydrpidde and 2 parts of water. With 6 inch test- 

 tubes, % inch diameter, the amounts advised are 3^ 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 hydro- 

 gen in a perfectly air-tight container. 

 The method of hermetically seahng 

 such containers full of hydrogen by 

 melting the glass in a flame is really 

 too dangerous to be recommended. 

 The apparatus devised by Novy is 

 most convenient and has practically 

 superseded all other devices for culti- 

 vation of anaerobes in hydrogen. The 

 Novy jar is especially valuable for plate 

 cultures. In using this jar, all ground- 

 glass surfaces 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 be- 

 tween the ground-glass surfaces, re- 

 gardless 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 together perfectly. A heavy rubber band may 

 then be passed around the cirfumference of the flanges to cover 

 the circle of contact. Finally two or three clamps, the jaws of 

 which are cushioned with cork or with rubber, are fastened on 

 the flanges, pressing them firmly together. The jar is now 

 attached to a source of pure hydrogen so that the gas enters at 

 the top of the jar. The other opening is connected with a wash 

 bottle containing water which serves as a valve. Hydrogen is 



Fig. 54. — Arrangement of 

 tubes for cultivation of anae- 

 robes by Buchner's method. 



