Nine studies and eight finished paintings from the period 1816-1856, all in oil, by the Norwegian painter J.C. Dahl, professor at the Dresden Academy, were examined by optical microscopy, infrared-photography and cross-sections, and analyzed by scanning electron microscope with an energy dispersive x-ray analyzer. The studies are done on paper, primed in various middle-tone colors, and painted <i>al prima</i> at a single sitting. Pigments identified are ultramarine (nat.); Prussian blue; yellow ochre; chrome yellow; Naples yellow; vermilion; iron oxide red; red ochre; organic reds; madder (?) and cochineal (?); black; lead white; quartz, chalk and barytes. The finished pictures are done on commercially prepared canvases with light primings. Underdrawings are in Chinese ink. The execution is generally <i>al prima</i>, and in bigger paintings the progress of the work can be followed through the overlappings of the * 2giornate*1. Pigments identified are ultramarine (art.); Prussian blue; lead monoxide; yellow, brown and red ochres; vermilion; organic red (madder?); bone black; lead white; bone white, barytes and chalk. The technique of the finished pictures is comparatively more uniform than the varied and unconventional structures of the studies. -- AATA