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…from the innermost surface of the Crater or mouth. In the Center of the Bottom, Nature seem’d to have constituted, as it were, her Harth of Fire: And to say truth, a Shop or Workhouse to make a Vulcanian Kitchin; boyling with an everlasting gushing forth, and streamings of Smoak and flames; and imply’d in decocting of Sulphur, Bitument, and melting…
https://www.wichita.edu/academics/fairmount_las/geology/wparcell/Kircher/volcanoes/chapter5.php