THE CULTIVATION OF BACTERIA. 85 



and to the right. When two tubes are being used at the 

 same time, as is often necessary, they are placed side by side 

 between the thumb and forefinger of the left hand. The 

 two plugs are held between the second and third and the 

 third and fourth fingers of the left hand, respectively. The 

 wire may now, be passed into the first tube, which we will 

 suppose to hold some material containing bacteria, and a 

 little of this material may be removed on the tip of the wire 

 from the first tube to the second. When the needle is intro- 

 duced into or removed from either tube it should not touch 

 the side of the tube at any point, and should only come in 

 contact with the region desired. After inoculation of the 

 second tube has been effected the wire is to be heated to a 

 red heat in the flame, the necks of the tubes are to be passed 

 through the flame, and the plugs are to be returned to their 



FIG. 19. 



Manner of Holding Tubes. 



respective tubes. When the wet wire is to be sterilized in the 

 flame it should be approached to the flame gradually, so as 

 to dry the material on it before burning it, in order to avoid 

 "sputtering" (see page 33). It is well from the start to 

 train one's self to sterilize the platinum wire every time it is 

 taken from the table and before it is laid down again. The 

 platinum wire loop may be used in the same manner as the 

 straight wire, especially when a substance containing a small 

 number of bacteria is being handled. 



