CULTIVATION OF ANAEROBIC BACTERIA. 133 



above the other in the rack c, and covered with the bell- 

 glass A. Liquid paraffin is poured in the dish B until it 

 is about half full. From a Kipp's apparatus hydrogen 

 gas enters the little rubber 

 tube #, subsequently escap- 

 ing by the tube b. When 

 only pure hydrogen escapes 

 the rubber tubes a and b are 

 withdrawn, and the appa- 

 ratus remains filled with hy- 

 drogen. Lest a little oxygen 

 should remain, it is best to 

 have the dishes at the top 

 and bottom of the neck filled 

 with alkaline pyrogallic acid. 

 Tetanus can be cultivated in 

 this apparatus. 



Roux has suggested the 

 simplest method of cultivat- ^ . . , ^ , 



FIG. 34. Botkm's apparatus for mak- 

 ing anaerobic bacteria. The ing ana e ro bic plate- cultures, 

 germs are distributed through 



freshly boiled, still liquid, gelatin or agar-agar, as in 

 making the dilutions for plate-cultures, then drawn into 

 a long, slender sterile piece of glass tubing of small 

 calibre. When the tube is full the ends, which should 

 have been narrowed, are closed in a flame, and the cul- 

 ture is hermetically sealed in an air-tight chamber. The 

 chief difficulty is in transplanting the growing colony. 

 To do this the tube must be opened with a file or a dia- 

 mond at the point where the colony desired is observed. 



