Recent work on the secondary electron emission properties of solids with less than 1/100 of a monolayer of adsorbed gas on the surface is reviewed. The solids were cleaved in a high vacuum so that secondary emission measurements could be completed in a time that was short compared to the monolayer adsorption time. The solids include graphite, NaCl, KCl, NaBr, KBr, and KI. The gases released from the alkali halides at the moment of cleavage were analyzed with a partial pressure analyzer.