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CONTENTS: 1. Geometry of Molecules as Revealed by Diffraction Meth-ods. 2. Behavior of Molecules in Electric and Magnetic Fields. 3.Molecular Spectra. 4. Primary and Secondary Valences. 5. CrystalStructure and Crystal Forces. 6. Crystal Structure and Symmetry. 7.Liquids, Mesophases and the Amorphous-Crystalline Character of Poly-mers. 8. Thermodynamics of Solutions. 9. Kinematics of Liquids andSolutions: Viscosity, Diffusion, and Ultracentrifugation. 10. MechanicalBehavior of High Polymers. 11. Step Reaction Polymerization. 12. ChainReaction Polymerization. 13. Degradation of High Polymers.

* STRUCTURE OF MOLECULES AND THE CHEMICAL BONDBy Y. K. SYRKIN and M. E. DYATKINATranslated and revised by M. A. Partridgeand D. 0. Jordan. 1950. 6 x 9*. 519pages, 87 illus., 174 tables. $8.75

CONTENTS: 1. The Hydrogen Atom. 2. Periodic Classification of theElements. 3. The Homopolar (Covalent) Bond. 4. Saturation and Di-rection of Valency Bonds. 5. Resonance of Valency Structures. 6Resonance of Covalent and Ionic States. 7. Methods of MolecularOrbitals. 8. Spectra of Diatomic Molecules. 9. Vibrational Frequenciesand Interatomic Distances in Polyatomic Molecules. 10. Dipole Moments.11. Bond Energies. 12. Intermolecular Attraction. 13. The ChemicalBond in Crystals. 14. Complex Compounds. 15. The Structure of theBoron Hydrides. 16. The Solution of the Three Electron Problem UsingSlater's Method. 17. The Polyelectron Problem and Resonance Energy.18. Mathematical Appendix. Formula and Radical Index.

ADVANCES IN COLLOID SCIENCE - Volume IIIEdited by H. MARK, Brooklyn, N. Y. andE. J. W. VERWEY, Eindhoven, Holland1950. 6 x 9. 396 pages, 180 illus., 36 tables.$7.50

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SCIENCE, Vol. 112

FOREIGN PERIODICALScovering the war years

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