The Neutron-Hydrogen Mass Difference and the Neutron Mass

Data in the literature leading to the neutron-hydrogen mass difference and the neutron mass are summarized. The disintegration energy of the deuteron together with the HH-D mass spectroscopic doublet separation apparently yields the best value of $n-H=0.755\mathrm{}\pm 0.016$ Mev and a neutron mass of 1.008,941±0.000,02 mass units. Other transmutation-radioactivity cycles check this value. Several inconsistencies in these data and their possible explanation are pointed out. Experiments of interest for improvement in accuracy and reliability of these values are noted.