In a dark attic, the old alchemist has set up a distillation apparatus. On the oven shown, partly cut to the left, there is a large copper kettle that is possibly filled with a liquid. A tube connects the top of the kettle with the glass globe that the alchemist has placed on a stool. The pipe is long enough for the steam to cool and condense. He is curiously waiting for the distillation product to start dropping into the glass globe. The large copper kettle looks like the type of still that is used in alcohol making. The construction of the distillation apparatus and the figure's red nose might indicate that he is producing liquor in secret, a process that would have been considered an alchemistic "transmutation" of the non-precious to the precious. Since Spitzweg briefly worked as a pharmacist after he had studied chemistry, he would have been familiar with this distillation process.
From the reflections on the glass globe that light up the bald forehead of the alchemist, we can assume that the light is coming through a small dormer window. Spitzweg selected a dark room and sparse light to paint the image in Rembrandt's manner; he had studied his work intensively.