Ergodicity, ensembles, irreversibility in Boltzmann and beyond
  The implications of the original misunderstanding of the etymology of the word "ergodic" are discussed, and the contents of a not too well known paper by Boltzmann are critically examined. The connection with the modern theory of Ruelle is attempted 
Giovannni Gallavotti (Dipartimento di Fisica, Universita' di Roma,   Roma)