Test of the linear relation between T-H (homogeneous ice nucleation temperature) and T-m (melting temperature) was carried out for aqueous HCl and H2SO4 solutions. It is shown that the linear relation does not hold for aqueous H2SO4 solution. Enhancement of the ionization of sulfuric acid with decreasing temperature is the most likely cause for the curved relation between T-H and T-m. In addition, close examination of the T-H and T-m data for aqueous HCl solution indicates that the T-H versus T-m relation for aqueous HCl solution seems very weakly curved. (C) 2011 Elsevier B. V. All rights reserved.