  Experimental values of Coulomb sums for q > 2 fm^(-1) are considered.
Assuming that a part of nucleons is modified in the nucleus, an approach is
offered, in the framework of which the calculation is in agreement with the
experimental data. It gives the nuclear matter density value, above which the
nucleon changes its properties. The radius of a modified proton is estimated,
the possibilities for a further investigation into its properties are
discussed.
