Capital punishment does not inspire roaring humor in healthy minds, so wit on the subject tends to be sardonic.  Two of the most famous examples, of course, are: “In this country it is wise to kill an admiral from time to time to encourage the others,”  and “Depend upon it, sir, when a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.”

The first, “pour encourager les autres,”  is in “Candide” where Voltaire alludes to the death by firing squad of Admiral John Byng in 1757 for having let Mincorca fall to the French.  The second was Samuel Johnson’s response to the hanging of an Anglican clergyman and royal chaplain William Dodd for a loan scam.  Byng’s...