Adam Walker, Natural Philosopher, Performing Scientific Experiments

A coloured etching after Gillray shows a hook-nosed lecturer hunched over a green-draped demonstration table crowded with flasks, retorts, wine glasses, and chemical apparatus. Above him float medallion portraits labeled Priestley and Franklin—the era's celebrity scientists—alongside a burning candle and a serpent coiling past alchemical symbols, mock-credentialing the showman below. The target is Adam Walker, a popular itinerant science lecturer whose paying audiences Gillray found ripe for ridicule: a charlatan dressed as a philosopher. Gillray's hand-coloured etching technique—acid-bitten line sharpened by burin, then tinted with watercolour wash—gave caricature a mass-print life that Hogarth had pioneered and Rowlandson extended. This tradition of numbered, sold-in-shops satirical prints is the direct commercial and visual ancestor of the comic strip panel: sequential wit compressed into a single charged image.