INDEX 



237 



Phosphorus losses from „ manure, 



212 

 Phosphorus requirements of plants, 



88 

 Pigments, bacterial, 50 

 Plant food, in water, 222 

 Plant requirements, 87, 171, 172 

 Plants, bacteria in, 1 6 

 Plants, classes of, 13 

 Plants, mutual relation of, 60 

 Plants, stimulated by antiseptics, 



203, 204 

 Plaster, 192, 193 

 Plasmolysis, 68 

 Poisons, influence on bacteria, 69, 



200-209 

 Potassium, in feeds, 210 

 Potassium, in manure, 211 

 Potassium, in soil, 82 

 Potassium, in Utah soil, 173 

 Potassium, in water, 223 

 Potassium requirements of plants, 



88 

 Potatoes, influence on nitrification, 



128 

 Pressure, influence on bacteria, 68 

 Priestley, 156 

 Protozoan theory, 205 

 Protista, 13 

 Pteridophytes, 13 

 Ptomaines, 48 



R 



Reaction, in ammonification, 1 1 5 



Redi, 3 



Reproduction, 25, 26, 27 



Residual Soils, 83 



Rotation, 174, 175 



Rothamsted Experiments, 135 

 with manure, 213 

 rotation, 174, 175 

 soil gain in nitrogen, 153 



Rontgen rays, 67 



Russell and Hutchin's Theory, 

 205 



s 



Salts, carried by water, 220, 225 



Schloesing and Mutz, 9, 1 20 



Schonbein, 119 



Schroeder, 6 



Schtilze, 6 



Shaking, effect on bacteria, 67 



Size of bacteria, 27, 28 



Soil alkali, influence on bacteria, 



190-199 

 Soil, bacteria in, 14 

 Soil bacteria, factors Influencing, 



92 

 Soil bacteria, number in soil, 91 

 Soil bacteria variation with depth, 



94 



Soil bacteriology, development of, 



l-ii 



Soil bacteriology, early history of, 

 8-1 1 



Soil, cellulose in, 183, 184 



Soil classes, 83 



Soil, durability of, 90, 173 



Soil fertility, influence of cellu- 

 lose on, 187, 188, 189 



Soil fertility, influence of legumes 

 on, 171-181 



Soil fertility, how maintained, 

 1 80-1 8 1 



Soil formation, 71-82 



