The sound of a kiss is not so loud as that of a cannon, but its echo lasts a deal longer.

Oliver Wendell Holmes, Sr. (1809-1894) American poet, essayist, scholar

The Professor at the Breakfast-Table, ch. 11 (1860)
    (Source)

The chapter originally appeared as "The Professor at the Breakfast-Table: What He Said, What He Heard, and What He Saw," Atlantic Monthly, (1859-11).