Data on the relationship between the electrical conductivity and the chemistry of ice cores from the polar regions are summarized. The electrical conductivity measurement is used as a proxy for dc conductivity, while dielectric profiling gives high-frequency conductivity. The dc conductivity seems to be controlled entirely by the acidity of the ice, with a secondary effect of the accompanying anion. There is no positive response when huge excesses of sea salt, ammonium, or calcium are present, except in ice where brine is present. The high-frequency conductivity is controlled by acidity, ammonium, and chloride. This finding can be accommodated within Jaccard theory, but the relative response at high frequency to the three ions seems puzzling. The possibility that dc conduction may be through grain boundaries can also not be discounted.