A noted anatomist, born at Copenhagen, where he studied medicine and kindred sciences with great enthusiasm; became widely known in European medical circles by his important investigations into the natural functions of glands (salivary and parotid), the heart, brain, &c.; in 1667 became physician to the Grand-Duke of Tuscany, residing at Florence, where he renounced Lutheranism for Catholicism; made valuable geological investigations, but finally gave himself up to a religious life; was created a bishop, and in 1677 Vicar-Apostolic of North Germany; chiefly remembered for his contributions to anatomical science (1638-1687).