A somewhat systematic attempt is being made to study the effect on electrical resistivity of zinc of small amounts of dissolved metallic impurities. In order to do this sets of single crystals have been made, each set containing a known percentage of some one impurity. The resistivities and some temperature coefficients of resistivity have been measured. The resistivity results include at the present data on sets of crystals containing 0.125, 0.25, 0.50 per cent of copper, gold, or silver, and 0.005% and.01 per cent iron. In all cases the resistivity increases with increase of added metal but not in a linear fashion. Iron has the most marked effect,.01 per cent iron producing as much increase as 0.5% copper. The temperature coefficient is lowered, depending on the added impurity. The ratio of principal resistivities, Q0/Q90, is about the same as for zinc crystals, i.e. with no added impurities
