THE CULTIVATION OF MICRO-ORGANlSMg 1 29 



Veillon Tube Cultxires.— Isolated colonies of anaerobic bac- 

 teria may be obtained by a modification of this tube method of 

 Liborius, which seems to have been used first by Veillon. The 

 principle of the method has been given on page 116. 



Fermentation Tube.— Anaerobic bacteria grow excellently 

 in the Smith fermentation tube filled with glucose broth, especially 

 if a small piece of naturally sterile liver or kidney from a small 

 animal, or a few cubic centimeters of naturally sterile defibrinated 

 blood be added to the medium in the tube. Glucose gelatin 

 to which litmus has been added also furnishes a medium in which 

 anaerobes will grow abundantly without any special precautions 

 to protect them from oxygen or from the air. 



Removal of Oxygen. — Anaerobic conditions may be furnished 

 by pumping out the air from a container in which the cultures 

 have been placed, a method employed by Pasteur. The oxygen 

 may be absorbed from the air by a mixture of pyrogallic acid 

 and alkali. Buchner's method is carried out as follows: Into 

 a bottle or jar, which can be tightly stoppered, pour 10 c.c. of a 

 6 per cent solution of sodium or potassium hydroxide, for each 

 100 c.c. of air contained in the jar. Add one gram of pyrogallic 

 acid for each 10 c.c. of solution. The culture-tube is placed 

 inside of the larger bottle or jar, supported above the bottom, 

 and the stopper, smeared with paraffin, is inserted. The mix- 

 ture of pyrogallic acid and potassium hydroxide possesses the 

 property of absorbing oxygen. 



Wright's Modification of Buchner's method: The tube of cul- 

 ture-medium is plugged with absorbent cotton, using a plug of 

 large size. The culture-medium is inoculated in the usual way. 

 The plug is cut off close to the neck of the tube, and is 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 

 sohition be freshly made and consist of about equal volumes of 

 pyrogallic acid and water, and that the second solution contain i 



