Complex sentence: At the age of ten (according to other references: thirteen) years he was apprenticed to his uncle Johann Georg Heine in Würzburg as an orthopaedic mechanic.Without amy enrolment he later attended lectures in medicine at the Würzburg university.
Split into simpler sentences: At the age of ten (according to other references, thirteen) years he was apprenticed to his uncle Johann Georg Heine in Würzburg as an orthopaedic mechanic. Without any enrolment he later attended lectures in medicine at the Würzburg university.