Inorganic acids or their alkali-metal or alkaline-earth salts are rather insoluble in ice. Ammonium ion, however, enhances the uptake of a variety of anions into the ice matrix. In the specific case of the fluoride this has been known for almost 50 years and attributed principally to isomorphism between the NH4F and ice crystal lattices. We report here that ammonium also enhances the solubility in ice of anions that do not fit easily into the ice structure. With the species pair HCl/NH4Cl we document specific effects of ammonium on anion uptake, static conductivity, and dielectric conductivity in ice. Other ion species for which comparable results have been obtained are mentioned. Possible implications for atmospheric processes are briefly discussed.