Many authors have attempted the derivation of fundamental equations of quantum mechanics from classical hydrodynamics. One can derive one of them, the Schrõdinger equation, assuming the non-mechanical, mezic type forces, similar to those, whose existence is supposed to exist in the relativistic hydrodynamics, to be responsible for inner sources of matter (positive or negative) in continuous electrically charged electron substance. Presuming, that the substance moves simultaneously under the influence of the electric field and at the same time diffuses opposite to the gradient of its density, one obtains a non-linear differential equation of continuity as condition for the establishment of states with discrete energies, which after linearization converts to the Schrõdinger equation.