wichita.edu
…suffocated in his too near approaches, and research after so great a Mystery of Nature; As witnesseth his Nephew, in an Epistle to Cornel. Tacitus. Not indeed willfully, and on set purpose, as ‘tis said, (but I think falsly) of the other grand Philosopher, that he threw himself into the contrary Element, because he could not understand the strange Mystery…
https://www.wichita.edu/academics/fairmount_las/geology/wparcell/Kircher/volcanoes/chapter5.php