Resistivity data as a function of temperature and composition have been obtained for solid solution alloys of &bgr;‐AgCd and &bgr;‐AuCd. Silver substitution for gold in &bgr;‐AuCd produces a lowering of the temperature of the diffusionless transformation and changes the nature of the transformation for the higher cadmium concentration alloys. Small substitutions of gold for silver in &bgr;‐AgCd also lower the transformation temperature while larger substitutions raise it. Ordering of gold and silver near the composition AgAuCd2has been observed by x‐ray diffraction and confirmed by residual resistivity measurements. This ordered structure is identical to that of the Heusler alloy; at lower temperatures ordered AgAuCd2transforms to a more complex phase. Separate disorderings involving the gold‐silver sublattice and the cadmium sublattice have been observed. Away from the composition AgAuCd2, residual resistivity measurements show the expected parabolic behavior. Some of these phenomena can be qualitatively explained in terms of ion‐core and electro‐negativity differences.