434 



SUBJECT INDEX 



Nitrification, influence of calcium on, 



142 



carbonate on, 139 

 of chloroform on, 210 

 of crop on, 231, 232, 233, 324, 325 

 of cultivation on, 230, 231 

 of fallow on, 231-233 

 of green manure on, 156-159 

 of gypsum on, 142 

 of iron sulphate on, 142 

 of light on, 230 

 of lime on, 141 

 of magnesium salts on, 143 

 of manganese salts on, 143, 144 

 of manure on, 153, 154, 155 

 of moisture on, 154, 155, 226-230 

 of organic matter on, 211, 222 

 of potassium salts on, 144, 145 

 of reaction on, 218, 219 

 of season on, 234 

 of sodium salts on, 144, 145 

 of temperature on, 230 

 of water-holding capacity of soil 



on, 228, 229 

 isolation of organisms concerned, 



211-215 



stimulation of, by salts, 147 

 toxicity of salts on, 149 

 Nitrifying ferments, distribution of, 



217, 218 



function of, in soil, 215 

 influence of depth of soil on, 218 



of heat on, 226 

 isolation of, 211-215 

 metabolism of, 223, 224 

 Nitrite nitrogen in soil, 228 

 Nitrobacter, 214, 216 

 morphology of, 226 

 sources of energy for, 214, 215 

 Nitrogen in crops, 320, 321 

 cycle, 183, 184 



fixation, chemical theory of, 249, 250 

 early theories of, 290, 291 

 energy for, 312 

 influence of aeration on, 312 

 of arsenic on, 120 

 of combined nitrogen on, 250 

 of cultivation on, 283 

 of fertilizers on, 313 

 of green manures on, 156-159 

 of heated soil on, 131 

 of manure on, 151 

 of moisture on, 312 

 of season on, 282 

 of temperature on, 279, 280, 313 

 mechanism of, 306-312 

 in soils, 34, 35 



fixed by Azotobacter, 264, 265 

 in legumes, 323, 324 

 liberation of, by bacteria, 243 

 losses in nitrification, 225 

 in nodules, 309 

 soil gains in, 287, 315, 316, 352 



Nitrogen, soil losses of, 239 



sources of, for bacteria, 68 



in Utah soils, 320, 325 

 "Nitrogen," 318 



Nitrosococcus, morphology of, 226 

 Nitrosomonas, influence of, on phos- 

 phates, 175 



media for, 220 



morphology of, 214, 225, 226 



sources of nitrogen for, 221 

 Nodule, ash of, 311 



bacterial growth of, 304, 305 



composition of, 309 

 Nuclein, action of bacteria on, 174 



OIDITJM lactis, action of, on lactic acid, 



87 



influence of pressure on, 107 

 in milk, 376 



Oleomargarine, tubercle bacilli in, 389 

 Organic compounds, action of, on 



Azotobacter, 259, 260 

 on denitrification, 243 

 in bacteria, 58 



as energy for Azotobacter, 262, 263 

 bacteria, 159 

 of soil, 193 

 manures, speed of decomposition, 



199 



Osmotic pressure, 67 

 on bacteria, 106 

 influence of, in soil, 149 

 Oxidation, of acids, 87 



incomplete, 82 

 Oxidizing enzymes, 79, 81 

 Oxygen, influence of, on bacteria, 105 

 requirements of bacteria, 69 



PATHOGENIC bacteria in cheese, 390 

 Peat, bacterized, 286 



denitrification in, 241 

 Penicillium, influence of salt on, 67 

 Peroxidascs, 81 

 Phosphate, action of bacteria on, 176 



reaction in soil, 175 



required by zymase, 83 

 Phosphoproteins, action of bacteria 



on, 174 



Phosphorus, action of cellulose fer- 

 ments on, 334 



cycle, 184-187 



requirements of Azotobacter, 257- 



258 

 of bacteria, 64 



in soil, 173 



in Utah soil, 320 



