Another version of this composition is signed and dated 1652 which suggests that this is the date of the present painting. The alchemist is a favourite subject of the period as it offers a chance to paint an interior with a innumerable inexplicable utensils (this is less crowded than most). The figure of the alchemist himself is usually (as here) an intense old, scholarly fool, lost in books and futile (though no doubt expensive) experiments. The owl is a symbol of folly and the hour-glass of the passage of time. A similarly satirical view of the over-complicated cant of alchemists is provided by Ben Jonson’s 1610 play of that name (especially act II, scene iii).