This foot note contained in document AFC07d025
4. Cotton Tufts apprised JA in Dec. 1785 of the claims of a Mr. Allen of Martha's Vineyard to extract fresh from salt water by filtering it through sand. Allen apparently attempted to persuade the American Academy of Arts and Sciences to pay him for the secret of his system. By February the scheme—which had been hailed as “The Most Useful Discovery of this Age of Discoveries” by the Massachusetts Centinel
—was revealed as a hoax. Unknown to observers, Allen wet the sand with fresh water before beginning the demonstration; the fresh water
would filter out, and Allen would close the spout before the salt water was released (Cotton Tufts to JA, 21 Dec. 1785, Adams Papers
; Massachusetts Centinel
, 17 Dec. 1785; The Belknap Papers
. Part III, MHS, Colls.
, 6th ser., 4 :308–309).
Cite web page as: Founding Families: Digital Editions of the Papers of the Winthrops and the Adamses, ed.C. James Taylor. Boston: Massachusetts Historical Society, 2007.