We all have our techniques for dealing with unwanted conversations and unpleasant people. Some may follow Calvin Coolidge’s example of responding with stony silence. Others may benefit from Abraham Lincoln’s practice of responding with a hotly-worded letter that would never get sent.
Sir William Harcourt (1827-1904), who served as the Home Secretary under United Kingdom Prime Minister William Gladstone, had his own method for handling unwelcome telephone calls. When caught in a conversation from which he wished to escape, Harcourt would pour ink into the telephone receiver, secure in the belief that it would trickle into either the ear or the mouth of the offending caller.
Source: Superior Person: A Portrait of Curzon and His Circle in Late Victorian England, by Kenneth Rose.