The origin of bands in the spectra of hardwoods and lignin is discussed and assignments are summarized. Eucalyptus regnans samples were progressively delignified by the sulfate, soda, and NSSC processes, and spectroscopic examinations were made at various stages on sections, milled wood, and thin paper sheets enclosed in potassium chloride pellets. The paper-in-KCl technique offers a reliable method of obtaining sharp and reproducible spectra of partially delignified pulps. Some aspects of the mechanism of NSSC pulping were studied, including the effect of temperature and the manner of fiber separation. The spectra of lignins recovered from the liquors and of Klason and Halse lignins from the pulps were also examined. Questions to which spectroscopy contributes include the presence of lignosulfonic acid in NSSC pulps, the nature of the sulfur linkages in sulfate lignin, and the lignin-carboydrate bond in wood. -- CCI