This journal provides immediate access to some articles. Volume 6(6); June 1920 Astronomy Studies of Magnitudes, in Star Clusters: XI. Frequency of Curves the Absolute Magnitude and Color Index for 1152 Giant Stars PMCID: PMC1084525 Chemistry Alkyl Amides of Isothiocyanacetic Acid PMCID: PMC1084524 Anomalous Osmose PMCID: PMC1084528 Genetics The Relative Importance of Heredity and Environment in Determining the Piebald Pattern of Guinea-Pigs PMCID: PMC1084532 Geology Fossil Plants from the Late Cretaceous of Tennessee PMCID: PMC1084533 Mathematics On the Distortion in Conformal Mapping When the Second Coefficient in the Mapping Function Has an Assigned Value PMCID: PMC1084526 Conformal Mapping of a Family of Real Conics on Another PMCID: PMC1084530 National Research Council Notes from the Minutes of the Meetings in January and February, 1920, of the Executive Board and Interim Committee of the National Research Council PMCID: PMC1084534 Report of the Meetings of the International Research Council and of the Affiliated Unions Held at Brussels, July 18-28, 1919 PMCID: PMC1084535 Report on the Organization of the International Astronomical Union PMCID: PMC1084536 Physics On the Springfield Rifle and the Leduc Formula PMCID: PMC1084523 On the Connection of the Specific Heats with the Equation of State of a Gas PMCID: PMC1084527 A Photographic Method of Finding the Instantaneous Velocity of Sound Waves at Points Near the Source PMCID: PMC1084529 Experiments on the Vibration of Air in Conical Horns PMCID: PMC1084531 Statistics On the Rate of Growth of the Population of the United States since 1790 and Its Mathematical Representation PMCID: PMC1084522 Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||