174 



BACTERIOLOGY. 



ing the wire. Now pass the inoculated wire into the tube, 

 and thoroughly mix the bacteria thus introduced, with the 

 gelatin. Then withdraw the wire, replace the cotton plug, 

 and sterilize the platinum wire in a flame. 



With a colored wax pencil, mark the tube thus inocu- 

 lated, 1. Likewise, mark another liquefied gelatin tube, 2. 

 Place tube 1 in the left hand, in the same position as be- 

 fore, and then place next to it tube 2 (Pig. 30). Remove 

 the cotton plug of tube 2, and place it between the adjoin- 

 ing index and middle fingers. Then remove the cotton plug 

 of tube 1, and place it between the ring and little finger. 

 Touch the flame of a burner to the necks of the tubes, in 

 order to burn off any loose cotton. Now, with a sterilized, 

 cooled platinum wire, the end of which is provided with a 

 small loop, transfer a loopful of gelatin from tube 1 to tube 

 2, and mix well. Return the same platinum wire to tube 1, 

 and again transfer a loopful of gelatin to tube 2. Repeat 

 this once more, so that all told, three transfers of inocu- 

 lated gelatin have been made. Replace the cotton plugs 

 in their respective tubes, sterilize the platinum wire and set 

 the tubes in a tumbler, the bottom of which is covered with 

 a layer of cotton. 



Fig. 30. Inoculation from tube to tube when diluting. 



Mark another liquefied gelatin tube, 3. Then place 2 

 in the position in which No. 1 was just held, and next to it 

 place tube 3. Remove the cotton plugs, place in their re- 

 spective positions, and flame the necks of the tubes as 



