CONTENTS XVll 



Effect of Ultraviolet Radlvtion Upon Active Principles .... 65 

 Effect of Dissolution and Arioi.vsis Upon the Active Prin- 

 ciples 65 



Meningococcus Preparations; B. Typhosus Preparations. 



Fluctuations in Potency of Active Principles 70 



Filtration and Dialysis of Active Principles 71 



Formalin Detoxification of Active Principles 75 



Use of Methods of Ecker and Rimington for Concentration 



and Purification of the Active Principles 75 



Ammonium Sulphate Precipitation of B. Typhosiis Active 



Principles 76 



Purified and Preserved Streptococcal Reacting Factors .... 78 



Purification of B. Coi i Preparations 79 



Chemical Studies on Active Principles of Vibrio Choler.e .... 81 



Chemical Studies on Active Principles of B. Pestis 82 



Nucleoprotein of B. pestis; Capsular Material of B. pestis. 



Chemical Studies on Active Principles of B. Dysenterle 83 



Attempts at Fractional Precipitation of Potent Bacterial 



Filtrates 84 



Recapitulation 87 



Chapter IV 



IMMUNOLOGICAL BEHAMOR OF ACTR E PRINCIPLES 



OF THE PHENOMENON OF LOCAL SKIN 



REACTIVITY 



Effect of Immune and Normal Sera Upon Skin-Prepar.\tc^ry 

 Factors 8g 



Effect of Normal and Immune Sera Upon Reacting Factors 93 

 Effect of Bacterial Variation Upon the Specificity of 



Active Principles 101 



Description of Strains and \'ariants; Serum Neutralizability 

 of Reacting Factors of Variants of B. typhosus and B. coli: 

 Morphological Appearance of Colonies and the Neutraliza- 

 bility of Reacting Factors; Serimi Agglutinabilitv of Various 

 Stock Strains and \'ariants of B. typhosus and the Neutraliza- 

 bility of Reacting Factors; Serum Precipitability of Culture 

 Filtrates of Various Stock Strains and Variants of B. typhosus 

 and Neutralizability of Reacting Factors; Virulence of B. 

 typhosus \'ariants and Neutralizability of B. typhosus React- 

 ing Factors. 



