"In fact, so intense has been the sympathetic engagement of audiences, that it has spawned a mass of anecdotes about people fainting, calling out, warning the characters, and threatening Iago. It is as though Othello bursts the limit between reality and fiction more readily than Shakespeare’s other tragedies. In 1825, when the American actor Edwin Forrest played Iago to Edmund Kean’s Othello, a man in the front row was heard to say, ‘You damn’d lying scoundrel, I would like to get hold of you after this show is over and wring your infernal neck.' Margaret Webster heard a girl in the audience whispering to herself over and over again ‘Oh God, don’t let him kill her . . . don’t let him kill her . . . ’ On the whole, it’s the women who cry out for Desdemona and the men who offer to fight Iago. As for the soldier on guard duty at a Baltimore theatre in 1822, it was presumably some potent combination of his profession and his racism that made him shout, as Stendhal reported: ‘ “It will never be said in my presence a confounded Negro has killed a white woman” ’. Whereupon he shot the white actor of Othello and broke his arm."
From Revelations of a Boston Physician by Charles Wistar Stevens:
"Mr. Blenkinsop watched attentively the scenes, and seemed to feel the reality of the fiction. I spoke to him several times; but he made me no answer, so much he was absorbed. And when Othello, having taken off his sword, takes up the feather-bed to smother the traduced Desdemona, and she, with the pathos of innocence, exclaims, “Kill me to-morrow, but let me live to-night! ” young Blenkinsop suddenly leaped over the railing (we were in the lowest box) and jumped over the footlights upon the stage. He then ran forward, and seizing Othello’s sword, which he had laid down, rushed at the jealous Moor, with murder in his eyes. Othello was at first stupefied, and gazed speechless at the intrepid avenger of Desdemona. Blenkinsop made a lunge at the actor and wounded him in the arm, while the actor, now starting up from his panic, took his only weapon, the feather-bed, and throwing it with full force and pressing it home, brought the madman to the ground; then following up his advantage, jumped upon it, and would have accomplished upon the poor maniac what he intended for Desdemona, had not the cries of the audience brought out the other actors,—lago, Gratiano, and Ludovico,—who drew away Othello and the feather- bed, and seized the supernumerary actor, who was playing in earnest. It was a terrible scene."