This journal provides immediate access to some articles. Volume 6(12); December 1920 Chemistry Hydrogen Ion Concentration of the Contents of the Small Intestine PMCID: PMC1084695 Geology The Kilauea Volcano Observatory PMCID: PMC1084702 Mathematics An Application of the Porism of Four Tangents of a Twisted Cubic PMCID: PMC1084700 Pathology Blood Concentration Changes in Influenza PMCID: PMC1084696 Physics Luminescence at High Temperatures PMCID: PMC1084697 Experiments with the Tube Resistance Furnace on the Effect of Potential Difference PMCID: PMC1084699 Zoology Preliminary Report on Pterergates in Pogonomyrmex Californicus PMCID: PMC1084694 Functional Regulations in Animals with Composite Spinal Cords PMCID: PMC1084698 Studies on the Transformation of the Intestinal Flora, with Special Reference to the Implantation of Bacillus Acidophilus: II. Feeding Experiments on Man PMCID: PMC1084701 Corrections The Influence of Ions on the Osmotic Pressure of Solutions PMCID: PMC1084703 Corrects: The Influence of Ions on the Osmotic Pressure of Solutions. Proc Natl Acad Sci U S A. 1920 April; 6(4): 211–217. On Kummer's Memoir of 1857 Concerning Fermat's Last Theorem PMCID: PMC1084704 Corrects: On Kummer's Memoir of 1857 Concerning Fermat's Last Theorem. Proc Natl Acad Sci U S A. 1920 May; 6(5): 266–269. On the Class Number of the Field Ω(e2iπ/pn) and the Second Case of Fermat's Last Theorem PMCID: PMC1084705 Corrects: On the Class Number of the Field Ω(e2iπ/pn) and the Second Case of Fermat's Last Theorem. Proc Natl Acad Sci U S A. 1920 July; 6(7): 416–421. Journal Matter Original table of contents page Administrative content — journal masthead, notices, indexes, etc. | ||