Who said "The mind must be constantly exercised to remain sharp."?

This quote is attributed to Frances Burney.

The mind must be constantly exercised to remain sharp. - Frances Burney

"The mind must be constantly exercised to remain sharp."

Frances Burney Wisdom

Novelist English 1752–1840

"Courage is the first requisite in a woman."

"Do you come to the woods expecting to find a sylph or a nymph? You will be disappointed."

"The world has always laughed at its own follies."

"I am not at all in a humour for talking."

"I'm not angry, I'm just disappointed."

"The best things in life are free."

"You can't have everything in life, but you can have what matters most."

"A woman's intuition is rarely wrong."