The first part presents the life and historical contributions of Maria
n Smoluchowski to the foundations of atomic theory of matter. Remainin
g parts are devoted to the presentation of the original derivation and
present applications of the Smoluchowski equations. Commonly used in
various physical, chemical, etc., problems is the kinetic Smoluchowski
equation, being the high-friction limit of the full Fokker-Planck equ
ation. Of less use so far has been the functional Smoluchowski (called
also Chapman-Enskog or Bachelier) equation. Within the scope of moder
n theory of stochastic processes this equation is an identity equivale
nt to the definition of a Markovian process. It is argued that, in the
view of the growing interest in non-Markovian stochastic processes, t
he functional Smoluchowski equation may become the most natural and ef
fective tool for checking the Markovian vs. non-Markovian character of
a considered process, especially when applied to experimental data. S
ome examples are given.