CONTENTS 



CHAPTEK 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- 

 ologyNatural Purification of Water Artificial Purification of Water 

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



CHAPTER 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 CO 2 in the Atmosphere : in Workshops, in 

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



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