He was born in London on 10 April 1816, the third son of Charles Penney, a wholesale stationer.
[2] He served an apprenticeship under Henry Hennell at Apothecaries' Hall, London 1833 to 1838 then went to Giessen University in central Germany where he obtained a doctorate (PhD) in 1839.
Then, on the recommendation of Thomas Graham he was appointed Professor of Chemistry at Anderson's College in Glasgow.
[3] He was an expert forensic witness in several famous murders where poison was suspected, including Madeleine Smith (1857) and Dr Edward William Pritchard (1865).
He married Miss Perry and had two daughters, one possibly from a previous relationship.