  We study the topological and fermionic vacuum structure of four-dimensional
QCD on the lattice by means of correlators of fermionic observables and
topological densities. We show the existence of strong local correlations
between the topological charge density and the quark condensate, charge and
chiral density. By analysis of individual gauge configurations, we visualize
that instantons (antiinstantons) carry positive (negative) chirality, whereas
the quark charge density fluctuates in sign within instantons.
