A determination of the thermal relaxation time of protons in pure water gives the value 3.6±0.2 sec, in very good agreement with theory. The ${\mathrm{O}}_2$ molecule in aqueous solution seems to have a ${\mu }_{\mathrm{eff}}$ of 1.2 Bohr magnetons for the relaxation processes.

• Received 2 November 1953

DOI:https://doi.org/10.1103/PhysRev.93.1241