This journal provides immediate access to some articles. Volume 13(4); April 1927 Astronomy On the Correction to Saha's Formula for Small Deviations from Thermodynamic Equilibrium PMCID: PMC1084922 Chemistry Chemical Constants and Absolute Entropy PMCID: PMC1084923 On Chemical Activation by Collisions PMCID: PMC1084924 A Case of Negative Catalysis in a Homogeneous System PMCID: PMC1084925 On the Determination of the Apparent Diameters of the Ions in the Debye-Hückel Theory of Strong Electrolytes PMCID: PMC1084926 Engineering Bending of a Quasi-Ellipsoidal Shell with Special Reference to Rigid Airships PMCID: PMC1084939 Influence of Iron Content on Mortar Strength PMCID: PMC1084940 Genetics Nucleus and Cytoplasm in Relation to Differential Pollen-Tube Growth PMCID: PMC1084935 Abnormalities in Pollen-Tube Growth in Datura Due to the Gene “Tricarpel” PMCID: PMC1084936 Magenta-Alpha—A Third Frequently Mutating Character in Drosophila Virilis PMCID: PMC1084937 Pollen-Tube Growth in Lythrum Salicaria PMCID: PMC1084938 Mathematics On the Expansion of Harmonic Functions in Terms of Harmonic Polynomials PMCID: PMC1084921 Physics New Infra-Red Absorption Bands of Methane PMCID: PMC1084927 On the Nature of Light PMCID: PMC1084928 Bands in the Extreme Ultra-Violet Spectrum of a Helium Discharge PMCID: PMC1084929 White-Light Interference Fringes with a Thick Glass Plate in One Path: Part II PMCID: PMC1084930 Molecular Space Array in Liquid Primary Normal Alcohols: The Cybotactic State PMCID: PMC1084931 Pinhole Probe Measurements with Massive Cylindrical Air Columns PMCID: PMC1084932 Atomic Lattices and Atomic Dimensions PMCID: PMC1084933 The Magnetic Dipole in Undulatory Mechanics PMCID: PMC1084934 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||