German army physician; born in Frankfort-on-the-Main (where his father was a physician), and took his degree at a German university. In 1753 he applied to the council of Frankfort for permission to practise, but the petition was refused. In 1760, however, he was appointed military physician of the imperial infantry regiment, under general master-of-ordnance Count von Macquard, whose regimental commander, Angelo de Pasquali, commended Mayer highly. Debates on the subject of the right of Jews to practise medicine took place for years between the council and the Jewish congregation.