532 



MICRO-ORGANISMS IN WATER 



Yeast forms, action of light on, 347 

 Yeast pink (' Rosa Hefe '), vitality 



in seltzer-water, 240 

 ' Yellow ' Bacillus (Lustig), 446 

 Yellow pigment, bacteria producing 



a, 444-449, 482, 483, 484, 498, 



503, 506, 507, 509 



Ziehl's solution, 46 



Zopfii, B,, 457 



Zurich, Lake of, bacteria in, 97, 110, 

 146 



— water supply, 144-147 



— — — typhoid fever and, 147 

 ZilrnianuTn, B., 487 



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, .LONDON 



