[en] We have measured the ⁵⁷Fe Moessbauer spectra of the Hofmann pyridine complex Fe(pyridine)₂Ni(CN)₄ sample before and after exposure to high pressure of gaseous xenon. The temperature dependence of the high spin molar fraction has been determined from the ⁵⁷Fe Moessbauer spectra. The spin transition of the sample without the high pressure treatment occurs between 175 and 220 K with a hysteresis width of 15 K. Although the ⁵⁷Fe Moessbauer spectra suggest that the spin crossover behavior of the sample before and after the high pressure treatment are almost the same, the hysteresis of the latter sample is somewhat larger. (author)