SUBJECT INDEX 



437 



Vinegar, bacteriology of, 411/412 



oxidase, 81 

 Vital movement, 41 

 Vitamin requirement of bacteria, 70 

 Vitamins in milk, 370 



W 



WATER, catalytic action of, 66 

 chemical purification of, 349 

 cholera due to, 352, 353 

 classes of bacteria in, 345, 346 

 classification of, 340, 341 

 disease and, 351-359 

 diseases transmitted by, 352 

 drainage, nitrogen in, 237 

 dysentery due to, 353 

 ground, 341 

 importance' of , 340 

 influence of, on ammonification, 200, 



201 



on Azotobacter, 276, 277 

 on denitrification, 244 

 of food on number of bacteria in, 



344, 345 

 of light on number of bacteria in, 



343 344 



on nitrification, 226-230 

 on nitrogen fixation, 276-278 

 on Ps. radicicola, 312, 313 

 of sedimentation on bacteria in, 

 343 



Water, influence of temperature on 



number of bacteria in, 344 

 intestinal bacteria in, 347 

 natural purification of, 347, 348 

 purification of, by alum, 349 



by chlorazine, 349 



by potassium permanganate, 349 

 soil bacteria in, 346, 347 

 solvent, 66 

 stored, 341 

 surface, 341 



typhoid due to, 354, 355 

 Water-holding capacity of soil, re- 

 lationship of, to ammonification, 



201 



YEAST, action of, on phosphates, 175 



as denitrifier, 240 



difference of, from bacteria, 30 



nitrogen fixed by, 252 



production of ammonia by, 194 

 Yellow fever, 26 



Z 



ZINC, action of, on bacteria, 123, 124 



Zoogloaa, 43 



Zymase, phosphorus requirements of, 



83 



Zymases, 80 

 Zymo-excitor, 76 

 Zymogen, 76 



