William Haseldine Pepys (1775-1856), English scientist. Pepys was born in London and at 14 was apprenticed to his father as a cutler. Working in his father?s company allowed him to do research in his leisure hours. In order to keep contact with fellow scientists, he was a founder of many societies, including the Askesian Society, Geological Society of London and the London Institution. His own work included studies of electrochemistry and electrostatics, the properties of carbon dioxide and ammonia and the chemical phenomena of respiration. He invented the mercury gasometer and a type of eudiometer and was elected fellow of the Royal Society in 1815.