VITALITY OF PUTREFACTIVE ORGANISMS. 139 



it,' as shown at a, fig, 12. Two-thirds of the cylinder 

 were occupied by the infusion. After the introduction 

 of the latter, the neck of the bulb was plugged with 

 cotton-wool, and hermetically sealed above the plug, 

 as at B, fig. 12. The bulbs were afterwards plunged in 

 water deep enough to cover their necks. The water was 



Fig. 12. 



gradually raised to the boiling-point, and maintained 

 at the boiling temperature for ten minutes. They 



• I have called them ' pipette-hulbs ' because they are formed 

 by hermetically sealing one shank of a pipette, close to the bnlb, 

 leaving the other shank open for the introduction of the infusions. 

 German pipettes, on account of their cheapness, were at first com- 

 monly used ; but in cases of long-continued boiling, explosions 

 were so frequent that bulbs of English glass of specially resistant 

 quality were resorted to. 



