Definition of "combustion"

From this ground, with a kind of loose scorn, he continues the French Correspondence, and secretly contriveth a continuance of the Scotish Rebellion. He omits no Act of Contempt against the antient Nobility, that they might in the sence of their disgrace be, or at least dayly threaten some new Combustion.

c. 1620s, Elizabeth Cary [misattributed to Henry Cary], The History Of the most unfortunate Prince King Edward II. […] , London: A.G. and F. P., published 1680, page 32

There [were] great combustions and divisions among the heads of the university.

c. 1665, John Worthington, “The Works of the Pious and Profoundly-learned Joseph Mede”, in Life, The Author

Him the Almighty Power / Hurld headlong flaming from th' Etherial Skie / With hideous Ruine and combustion down / To bottomless perdition, there to dwell / In Adamantine Chains and penal Fire, / Who durst defie th' Omnipotent to Arms.

1667, John Milton, “Book I”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, lines 44–49

But say from whence this new combustion springs.

1675, John Dryden, Aureng-zebe: A Tragedy. […], London: […] T[homas] N[ewcomb] for Henry Herringman, […], published 1676, (please specify the page number)