Date: 1791

One may bear a "milky mind"

— Cowper, William (1731-1800)

Date: 1815

The wavering motions of the mind are like "quivering light" reflected off a confined "crystal flood" in a brass cistern

— Cowper, William (1731-1800)

Date: 1903

"When you wish to instruct, be brief; that men's minds may take in quickly what you say, learn its lesson, and retain it faithfully. Every word that is unnecessary only pours over the side of the brimming mind."

— Wickham, E. C. (1834-1910); Quintus Horatius Flaccus [Horace] (65 BC - 8 BC)