After surviving the plague that raged in 1630 and closed the university for two years, he was offered a professorship in botany in 1632, combined with the management of Orto botanico di Padova.

[4] Advised by French librarian and scholar Gabriel Naudé, and benefiting from his proximity to the printing and book trade metropolis of Venice, he built up a significant private library.

Rhodius wrote a guide to studying medicine, with detailed bibliographical references, which were initially only printed locally and were only made known to a wider readership after his death by medical scholars Thomas Bartholin and Hermann Conring.

[5] In his writings on the history of medicine, he made the work of ancient Roman physicians Aulus Cornelius Celsus and Scribonius Largus accessible to the students of his time with an explanatory commentary.

He was able to publish some of them; however, a large part, including Rode's edition of De medicina of Celsus, were destroyed in a fire in Bartholin's library in 1670.

The archaeological antiquities he collected in Italy were acquired by the physician Thomas Fuiren (1616–1674) for his cabinet of curiosities; through his testamentary donation they were given to the University of Copenhagen, which later exhibited them for some time.