An Alchemist,' by Adriaen van Ostade, 1661.The old belief that alchemists could turn base metals into silver and gold survived until the 18th century, and other Dutch paintings of the 17th century satirised the same theme. Here, the paper beside the stool bears an inscription from the treatise 'De Re Metallica' by Agricola (1556): 'oleum et operam perdis' ('oil and work is wasted'). Prominence is given to the still life of varied utensils in the foreground, while the alchemist's family - a mother wiping her baby's bottom - is relegated to the background.