[A Philosopher Shewing an Experiment on the Air Pump] / Jos. Wright Pinxit. 1768; J. Boydell, excudit ; Val. Green fecit, Londini 1769. - [2nd state]. - 1print: mezzotint [cut to] platemark 48.7x59.2cm, image 45.2x59.2cm. in wood veneer and gilt frame, 76x85.5x4cm. - After the oil painting by Joseph Wright of Derby, 1768. - Subject: A dramatic moment in a night scientific lecture on pneumatics; the inevitability of laws of nature, and assorted human responses, reflected by light source of candle behind glass jar with skull, traditional symbols of mortality; on table, a pair of Magdeburg hemispheres, etc; dominated by air pump apparatus with white cockatoo almost lifeless at base of glass receiver, from which air pumped out; lecturer's l.hand poised on stopcock, r.hand gesturing to skull, looks direct to viewer; moment of choice and uncertain (divine) outcome