32 



BACTERIOLOGY 



a centrifugal machine, or centrifuge, to be driven by hand. 

 This contrivance carries a metal frame or a disc with several 

 apertures in which are fixed metal cases for the reception 

 of small glass tubes. The fluid to be examined is poured 



Fig. 20.— Stesbeok's Centrifuge (after Jakscli). 



into the small tubes, which are provided at their lower end 

 with a little reservoir communicating with them through 

 a conical constriction, and in which the precipitate gathers 

 when thrown to the bottom. This centrifugal machine 

 has been several times modified by Von Jaksch (fig. 20). 



