He was head of Theoretical Physics at Jagiellonian University from 1899 to 1935. He published a series of papers on the problems of thermodynamically irreversible processes, gaining him recognition in the rapidly growing field. He was the first to take into account the distinguishability of photons in the statistical analysis of elementary processes, being a precursor of the notion of quantum indistinguishability - he discovered a quantum statistics, rediscovered 11 years later by Satyendra Nath Bose and generalized by Albert Einstein - the so-called Bose-Einstein statistics. 
^Max Jammer (1966). The conceptual development of quantum mechanics. McGraw-Hill. p. 51. ISBN0-88318-617-9.
^Natanson, Władysław (1911). "On the statistical theory of radiation". Bulletin de l'Académie des Sciences de Cracovie (A): 134–148. Natanson, Władysław (1911). "Über die statistische Theorie der Strahlung". Physikalische Zeitschrift. 12: 659–666.