Contents

1. Selectivity in the service of man 2. Steps in the correlation of structure with biological action 3. Differences in distribution: the first principle of selectivity 4. Comparative biochemistry: the second principle of selectivity 5. Comparativity cytology: the third principle of slelectivity 6. Chemotherapy: history and principles 7. Pharmacodynamics 8. The nature of chemical bonds Adsoroption 9. Metabolites, enzymes, and metabolite analogues 10. Ionization 11. Metal-binding substances 12. The covalent bond is selective toxicity 13. Steric factos.14. Surface chemistry The modification of membranes by surfaceactive agents 15. Biological activity unrelated to structure. Ferguson’s principle 16. The perfection of a discovery