8o 



MANUAL OF BACTERIOLOGY. 



above the bottom, and the stopper, smeared with paraffin, is 

 inserted. The mixture of pyrogalUc acid and potassium hy- 

 droxide possesses the property of absorbing oxygen. 



Wright's Modification oj Buchner's Method: The tube of 

 culture-medium is to be plugged with absorbent cotton, using a 



plug of large size. The cul- 

 ture-medium is inoculated in 

 the usual way. The plug is 

 cut o£f close to the neck of 

 the tube, and is then pushed 

 into the tube about i centi- 

 meter. Now allow a watery 

 solution of pyrogaUic 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 pyrogaUic acid and 

 water, and that the second so- 

 lution 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 pyrogaUic 

 acid, I c.c. solution of sodium 

 hydroxide. 



Cultivation of Anaerobic Bacteria under Hydrogen: Method 

 of Liborius Modified by Frdnkel: A test-tube containing a large 

 amount of the liquefied culture-medium is closed with a steri- 

 lized rubber stopper, through which pass two sterihzed glass 

 tubes, bent above the stopper at a right angle. One of these 



Fig. 26. — Arrangement oe 

 Tubes eor Cultivation oe 

 Anaerobes by Buchner's 

 Method. 



