! 



II 



FIG. 104. BACTERICIDAL TEST (LOOPED PIPET METHOD OF WRIGHT). 

 The pipet shown on the extreme left contains the mannite-litmus broth and an 

 equal volume of patient's serum and emulsion of typhoid bacilli; the second pipet 

 shows the serum and bacillary emulsion mixed; the middle pipet shows the serum- 

 bacillary mixture cultured in the broth; the fourth pipet shows acid production in 

 the broth by living bacilli which escaped destruction after twenty-four hours' incuba- 

 tion; the fifth pipet (extreme right) is the serum control. The broth, being clear 

 and unchanged, shows that the serum was sterile. 



