CONTENTS 



CHAPTEE I 



THE BIOLOGY OF BACTERIA 



PAGE 



Early work — Place of Bacteria in Nature — Biology of Bacteria ; Morphology, 

 Composition, Reproduction, Influence of External Conditions — Light 

 — Modes of Bacterial Action — Seed and Soil — Specificity of Bacteria 

 — Association, Antagonism, Attenuation — Bacterial Diseases of Plants 1-32 



CHAPTER II 



BACTERIA IN WATER 



Quantity of Bacteria in Water — Quality of Water Bacteria: (a) Ordinary 

 Water Bacteria ; (6) Sewage Bacteria ; B. coli communis ; (c) Patho- 

 genic Bacteria in Water — Interpretation of the Findings of Bacteri- 

 ology — Natural Purification of Water — Artificial Purification of Water 

 — Sand Filtration — Domestic Purification of Water . . . 33-72 



CHAPTEE III 



BACTERIA IN THE AIR 



Methods of Examination of Air — Conditions of Bacterial Contamination of 

 Air : (1) Dust and Air Pollution ; (2) Moisture or Dampness of Surfaces : 

 Bacteria in Sewer Air ; (3) the Influence of Gravity ; (4) Air Currents. 

 The Relation of Bacteria to CO2 in the Atmosphere : in Workshops, in 

 Bakehouses, in Railway Tubes, in the House of Commons . . 73-91 



xill 



