Dr. Reynolds will continue his investigation into the nature and origin of warm ionized gas in the interstellar medium. This gas is a major, newly identified component of the medium about which very little is known. An accurate understanding of interstellar matter and processes is going to require as thorough an investigation of this ionized component as of the other principal components of the medium. The work will concentrate on observations of the structure and kinematics of the ionized regions, the relationship between the regions of ionized gas and regions of neutral hydrogen at high Galactic latitude, and the ionization conditions within the gas. The observations will be carried out with the large aperture Fabry-Perot spectrometer at the University of Wisconsin, which has made possible the detection and study of the faint optical line emission from this gas, and which as a result has become the primary source of information about the properties of this last major component of the interstellar medium. Developments in the instrumentation will provide significant improvements in the observational capabilities and will help to open up further this new area of interstellar medium astronomy.