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Published online by Cambridge University Press: 14 August 2015
In whatever physical state the gas is found, observations of the interstellar medium in elliptical galaxies are of considerable interest. This is particularly true in the case of radio galaxies where we believe that the gas is an indespensable part of the cause of nuclear activity and plays a role in the origin and the evolution of the radio galaxy phenomenon. In a few cases we are fortunate to find some of the gas to be ionized with a temperature of about 104 K where optical spectroscopy allows us to deduce something about the excitation/ionization mechanism, about its chemical composition and about its state of motion. Here I wish to summarize observations of three Southern radio galaxies which show optical emission lines from regions tens of kiloparsecs in extent.