Index and Glossary 



483 



Potash, carbonate of, 2G3; character 

 of, in soil, 290; influence of carbon 

 dioxid on, 290; relation of humus to, 

 291; relation of lime to, 291; re- 

 lation to soil bacteria, 292, 293; 

 relation to weathering, 290; salts, 

 influence of, on soil bacteria, 292. 



Prazmowski, 213. 



Preservatives, 42, 438. 



Pressure, influence of, on bacteria, 

 41, 42. 



Proteins (complex organic substances 

 containing about 16 per cent of 

 nitrogen), 32. 



Protoplasm, (the active substance of 

 living cells in which the chemical 

 reactions necessary for organized 

 life take place), 17, 27, 29. 



Protozoa (minute, one-celled animals), 

 72 



PseudomonaSt 19. 



Ptomaines, 417. 



Pugh, 193. 



Pure cultures (the growth of any sin- 

 gle species of microorganisms in 

 suitable media), in vinegar- ma king, 

 472. 



Quick vinegar method, 468, 469. 



Rancidity of butter, 412, 413. 



Reaction of soils, 44. 



Rennet, 419. 



Resistance, 11. 



Respiration and bacteria, 54, 55. 



Ripening of cheeSe, 416, 417, 419-422; 

 cream, 402, 404. 



Rivers and sewage, 105; bacteria in, 

 77; Pollution Act, 106; self-purifi- 

 cation, of 79. 



Rod-shaped forms, 15. 



Ropy wine, 460. 



Roquefort cheese, 422, 426. 



Rotation of crops, 239, 241. 



Rothamsted soils, azotobacter in, 

 204. 



Ruasel, 310, 419. 



Rye grass, 131. 

 Rye straw, 30. 



Saccharobacillus pastorianus, 459. 



Saccharomyces pastorianus, 381. 



Salting of foods, 440. 



Saltpeter, origin of, 168. 



Sand Alters, 82, 83. 



Sand vetch, 251. 



Sarcina, sickness of wine, 460. 



Sauerkraut, bacteria in, 441, 443; 

 preparation of, 442; presence of 

 lactic acid in, 443. 



Scarlet fever and r^ilk, 401. 



Schloesing, 115, 116, 168. 195. 



Schneidewind, 355. 



Schoenbein, 184, 193. 



Schroeder and Dush, 5. 



Schroeter, 7. 



Schubert, 206. 



Schultz. 242, 259. 261, 288. 



Schultze, 4. 



Schwann, 6. 



Sea-air, bacteria in, 51. 



Sedimentation (the gradual settling 

 out of solids suspended in water), 

 72, 73, 88. 



Self -purification (the natural tendency 

 for the decomposition and disap- 

 pearance of organic substances in 

 streams or other bodies of water), 

 of streams, 66, 79. 



Septic tank, 114, 117, 118, 122. 



Septic tanks (covered or uncovered 

 pits in which a large portion of the 

 organic matter in sewage is decom- 

 posed by anaerobic bacteria), in- 

 oculation of, 121; kinds of bacteria 

 in, 121. 



Settling basins (tanks, pits, or de- 

 pressions in the ground, in which 

 suspended solids in sewage or water 

 gradually settle out), 81. 



Severin, 306. 



Sewage, and rivers, 105; bacteria in, 

 103, 108; bacterial purification of, 

 112, 122; clogging of soil with, 129; 



