Data are given on the thermoelectric power and on the resistivity of the dilute alloys, Cu☒Si, Ni☒Si, and Fe☒Si, from −195° to +500°C (and higher for some of the alloys). The Cu☒Si thermopower at first decreases with increasing Si content and then again increases, the minimum being at about 2 or 3 atomic percent Si, depending on the temperature. The Cu☒Si resistivity is typical of Cu‐base alloys, the resistivity increases per atomic percent Si changing from 7.2 μΩ cm at −190°C to 8.7 μΩ cm at 840°C. The thermopower and resistivity curves for Ni☒Si show a characteristic knick at the Curie temperature of each alloy. The Fe☒Si thermopowers are positive at lower temperatures and become negative at a temperature T0 which decreases with increasing Si content. Furthermore, T0 changes from about 300°C for pure iron to about +70°C for 2 atomic percent Si. The resistivity of Fe☒Si alloys increases faster than linearly with temperature, and this is also the case for the Ni☒Si alloys below the Curie temperature. Above the Curie temperature, the Ni☒Si resistivities vary linearly with temperature. The increase in resistivity per atomic percent Si in Fe is 10.5 μΩ cm at all temperatures within the measured range.