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… Nature. For how else could there be every where such a quantity of Minerals, brimstone, and sulphurous unctuous matters, without any fire and subterraneous burnings of fire engendring, and all concocting nature; which by no means can be conceived to be enkindled, from the conflicts of air and moisture, in those most dark and deep Regions of the Earth, so…
https://www.wichita.edu/academics/fairmount_las/geology/wparcell/Kircher/volcanoes/chapter1.php