Sentence:  But if they ſtill continue obſtinate, or offer to raiſe Inſurrections, he proceeds to the laſt Remedy, by letting the Iſland drop directly upon their Heads, which makes a universal Deſtruction both of Houſes and Men. However, this is an <WSD>Extremity</WSD> to which the Prince is ſeldom driven, neither indeed is he willing to put it in execution, nor dare his Miniſters adviſe him to an Action, which, as it would render them odious to the People, ſo it would be a great damage to their own Eſtates, which lie all below, for the Iſland is the King's demesne 
Meaning of the word marked with <WSD> tags:  An extreme measure.