Thus we read in the laws of Æthelstan: “That no thief be spared over xii pence, and no person over xii years, who we learn, according to folk-right, that he is guilty, and can make no denial: that we slay him and take all that he has.”
— from Tyburn Tree: Its History and Annals by Alfred Marks

You, the chief of the secret police of X——, you don’t know!”
— from The Idler Magazine, Vol III. May 1893 An Illustrated Monthly by Various

"Poor old X," you think, "how damnable to lose him.
— from Cavalry of the Clouds by Alan Bott

If [pg 310] you had no pity on Xerophrastes, you might at least have had some for the pretty widow.”
— from Valerius. A Roman Story by J. G. (John Gibson) Lockhart

Original MONG the sham agents must be classed the “Professors,” or “X. Y. Z.‘s,” who are always “able to place two or three” (never more than two or three: it would be no use four applying) “lady and gentlemen amateurs, of tall or medium stature, either dark or fair, but must be of good appearance, at a leading West-end theater, in good parts: Salaried engagement.”
— from On the Stage--and Off: The Brief Career of a Would-Be Actor by Jerome K. (Jerome Klapka) Jerome