XVI CONTENTS 
Bacteriophage 636 
Resistance of Phage to Physical and Chemical Agents 637 
The Nature of Phage 638 
Rickettsia Bodies 638 
Typhus Fever (Tabardillo, Brill 's Disease) 640 
Trench Fever (Wolhynian Fever, Fievre de Volhynie, Werner-Hiss 
Disease) 644 
Rocky Mountain Spotted Fever 646 
Diseases of Unknown Etiology 648 
Measles 648 
Rabies 649 
Trachoma 653 
Smallpox (Variola) and Vaccinia 654 
Mumps 659 
SECTION IV. 
GASTRO-INTESTINAL BACTERIOLOGY. 
CHAPTER XXIX. 
Gastro-intestinal Bacteriology. 
General Considerations 661 
The Gastro-intestinal Flora of Normal Infants, Adolescents and Adults . . 663 
Distribution of the Intestinal Flora of the Normal Nursling .... 665 
Distribution of the Intestinal Flora of Artificially-fed Infants . . 666 
Distriblition of the Intestinal Flora in the Adolescent and Adult . . 668 
Significance of Intestinal Bacteria 670 
Bromatherapy 677 
SECTION V. 
APPLIED BACTERIOLOGY 
CHAPTER XXX. 
Bacteriology of Milk. 
Sources of Bacterial Contamination of Milk 684 
Estimation of the Bacterial Content of Milk 684 
Identification of Bacteria in Milk 687 
Milk in Its Relation to the Public Health 689 
Cellular Elements of Milk 693 
CHAPTER XXXI. 
Bacteriology Of the Soil, Water and Air. 
Soil 694 
Water and Sewage 698 
Bacteriological E.xaniination of Water 700 
Collection of Sample 700 
Bacteriological Analysis of Water 700 
Counting Bacteria 701 
Technique of Plating 701 
Interpretation of Bacterial Count 701 
Bacteria of the Air 703 
