Gerard "Gerrit" Leendertszoon Blasius (Amsterdam, 1627 – Amsterdam, 1682 ) was a Dutch physician and anatomist. He was the eldest son of Leonard Blasius (-1644), who had worked as an architect in Copenhagen. Gerard started his studies there, but the family moved to Leiden, after his father died. Around 1655 he became a physician in Amsterdam. In October 1659 Blasius was appointed at the Athenaeum Illustre but without being paid. In the next year he became the first Amsterdam professor in medicine. At his home or in the hospital corpses were dissected. In 1661 he claimed the discovery of Stensen's duct by his pupil Nicolas Stensen.
Blasius had married Cornelia van Ottinga in 1653.His younger brother was the poet Joan BlasiusA list of works:
Disputatio physica de principatu cordis, etc Praes Albertus Kyper (1655)Impetus Jacobi Primerosii doctoris medici, in Vop. Fort. Plempium ... retusus / a Gerardo Leon. Blasio (1659)Commentaria, in syntagma anatomicum ... Joann. Veslingii / Ger. Leon. BlasiusOratio inauguralis de iis quae homo naturae, quae arti, debeat. / Gerardus Leon. BlasiusAnatome contracta (1660)Medicina generalis nova accurataque methodo fundamenta exhibens / Gerardus Leonardi Blasius (1661)Pest-geneesing en bewaaring voor dezelve. (1663)Observata anatomica in homine, simia, equo variisque animalibus aliis Accedunt extraordinaria in homine reperta praxin medicam aeque ac anatomen illustrantia n (1664)Medicina universa; hygieines et therapeutices fundamenta methodo nova brevissimè exhibens (1665) Gerardi Blasii, ab Oost-vliet ...Anatome medullae spinalis, et nervorum inde provenientium (1666)Anatome contracta, in gratiam discipulorum conscripta, & edita (1666)Observationes anatomicae selectiores collegii privati Amstelodamensis, figuris aliquot illustrObservationes anatomicae selectiores amstelodamensium 1667, 1671Institutionum medicarum compendium, disputationibus XII ... absolutum / Gerardus Leon. BlasiusMiscellanea anatomica, hominis, brutorumque variorum, fabricam diversam magnâ parte exhibentia (1673) Gerardi Blasii med. doct. & prof.Observata anatomica in homine, simiâ, equo, vitulo, ove, testudine, echino, glire, serpente, ardeâ, Gerardi Blasii ab Oost-Vliet ... variisque animalibus aliis. : Accedunt extraordinaria in homine reperta, praxin medicinam æque ac anatomen illustrantia (1674)Ontleeding des menschelyken lichaems / beschreeven en in verscheydene figuren afgebeelt door Geerard Blasius (1675) [2]Observationes medicae anatomicae rariores (1677)Observationes medicae rariores in quibus multa ad anatomiam et medicinam spectantia detegunturZootomiae, seu Anatomes variorum animalium pars prima (1676)Medicina curatoria methodo nova in gratiam discipulorum conscripta (1680)Anatome animalium, terrestrium variorum, volatilium, aquatilium, serpentum, insectorum, ovorumque, structuram naturalem ... figuris variis illustrata (1681)
