viii CONTENTS 



8. Salmonella Antigens 103 



Endotoxins 103 



The Salmonella . 105 



Chemistry of the Polysaccharide Component of 



Salmonella Antigens 107 



Relation of Structure of Salmonella Antigens to Specificity 108 

 Cross-Reactions 112 



9. Union of Antibody with Antigen: Thermodynamics 118 



Forces Involved 1 18 



Energy 124 



Entropy 127 



Free Energy 129 



Free Energy and Equilibrium 131 



10. Energy of Antibody-Antigen Reactions 134 



Direct Calorimetry 134 



Free Energy from Equilibrium Measurements 135 



Significance of Thermodynamic Constants 140 



Heat of Reaction of Isoagglutinins 145 



Index 1 5 1 



