2S6 



Subject Index. 



Oxgyen, effect on stored samples, 



35- 

 Oxygen, effect on viability of bac- 

 illi in water, i8, 19. 



Paracolon bacilli, iii, 116, 166, 



167. 

 Paracolon group, 127. 

 Paratyphoid bacilli, 163. 

 Paratyphoid organisms, 116. 

 Parietti's solution, 67. 

 Pathogenes in water, 67. 

 Peptone, effect of kind on counts, 



39- 

 Phenol agar, 8g. 

 Phenolated gelatin, 68. 

 Plating, procedure, 36, 37, 38. 

 Polluted waters, acid producers 



in, 60. 

 Polluted waters, body temperature 



count, 60. 

 waters, examination of, 60. 

 Porous tops, 59. 

 Potato gelatin^ 68. 

 Precipitants for typhoid isolation, 



_7S; 

 Precipitation methods, 69. 

 Preliminary cultivation, 213. 

 Preliminary enrichment for B. 



coli, 89. 

 Presumptive test, correctness of, 



144- 

 test, effect of temperature on, 



I4S- 

 test in absence of B. coli, 145. 

 test, with highly polluted waters, 



144. 

 test, interpretation, 143. 

 tests, 176. 

 tests for B. coli, 141. 



Progressive pollution, 179. 

 Proteus group, 168. 

 Protozoa, effect of, 15. 

 Pumping, effect of, 31. 



Quantitative bacteriological exam- 

 ination, 25. 



Rain water, bacteria in, 6. 



Ratio of acid producers to total 



count, 64. 

 Record blank, 106. 

 Recording counts, 44. 

 Red colonies, count of, 175. 

 Reduction processes in sewage, 



201. 

 Relation of total count to body 



temperature count, 61, 62, 63. 

 Results, interpretation of, 46. 

 River waters, bacteria in, 8. 



Sample, growth of bacteria in, 33, 



34, 35- 

 Sampling, 29. 



at great depths, 32. 

 effect of size of bottle, 35. 

 surface waters, 32. 

 Sand filters compared with me- 

 chanical filters, 54. 

 Sand filtration, 52. 

 Sanitary analysis, interpretation 



of, 183. 

 Seasonal distribution, 65. 

 variation of bacteria in streams, 



7,8. 

 variation in reservoirs, 11. 

 Sea-water, bacteria in, 13. 

 Sedimentation, 14, 15. 

 Self-purification, 19, 125. 

 agencies, 14. * 

 in Chicago drainage canal, 182. 



