After measuring the a(1) of isotope 1 of which we know the I(1) and µ(1) I would measure the a(2) of isotope 2 of which i know I(2). By looking at the ratio between the two measured a’s, a(2)/a(1), the factors that are determined by the electron cloud would cancel out leaving a ratio µ(2)I(1)/µ(1)I(2). Because we know the nuclear spins of the isotopes and we know µ(1) calculating µ(2) is now straight forward. This derivation presumes that adding neutrons to the nucleus does not alter the electron cloud, which is probably true considering the only way the electron orbits would alter is with gravitation. This will be only an incredibly small effect.