The Magnetic Susceptibility of Oxygen, Hydrogen and Helium

The method used was that of balancing the gas magnetically against an aqueous solution of nickel chloride. By varying the concentration of the solution it could be given a susceptibility approximately the same as that of the gas; then by varying the pressure of the gas or the temperature of the gas and solution, both could be given the same susceptibility. A manometric balance of great sensitivity enabled the observer to tell when the susceptibilities of the gas and the solution were the same. For both paramagnetic and diamagnetic gases, formulas are derived from which the susceptibility may be calculated from pressure and temperature observations on the gas when it is magnetically neutral against the solution. The volume susceptibility under a pressure of one atmosphere at the temperature 20^ was found to be +0. 144710^-6 for oxygen; -1. 6410^-10 for hydrogen, and -0. 8110^-10 for helium. The result found for helium is about 25 times less than T\"anzler's value, but when substituted in the formula derived by W. Pauli Jr. for the diamagnetic susceptibility of a monatomic gas, it yields a result bearing on the dimensions of the atom which is compatible with our knowledge obtained from other sources.