Matter is pictured as a primitive fluid substratum having the fundamental property of fluctuating at a constant frequency. From this are derived the discrete properties of space and time, and it follows that, at the microlevel, talk of pure space and pure time involves us in ambiguities. A new interpretation of Planck's constant emerges according to which it is a quantum of matter-time combination. Thus, a quantum of matter-space combination should exist. On pursuing further the hydrodynamic model, such a constant (...) is in fact discovered as the drag-quantum of the quantum fluid. A fourth-degree differential equation is considered which, with the help of this new constant, generates spectra of frequency, mass, and fine structure constants. The theory seems to answer some important fundamental questions. (shrink)