[en] Absolute values are presented for the total cross sections for interaction of 100-MeV α particles with ⁵⁰Ti, ⁵²Cr, ⁵⁴/sup ,/⁵⁸Fe, and ⁵⁸/sup ,/⁶⁴Ni. The features of measurement of the reaction cross sections by the method of charge integration at α-particle energies --100 MeV are described. It has been observed that the total cross sections for reactions in isotopes with N = 28 decrease with increase of the mass number, while in the isotopes of iron and nickel they rise more rapidly than the geometrical size of the nuclei increases. The different behavior of the reaction cross sections in isotones and isotopes is explained on the assumption that the density of distribution of the neutrons in the boundary layer of the nucleus differs, both for isotopes and for isotones