July 23, 1800: French patent granted to James Smith, ‘Citizen’ Ciuchet and Denis Monfort for an elaborate filtration device consisting of layers of wool, 2 inches crushed sandstone, 12 inches coarse powdered charcoal pressed into a solid with river sand, and 12 inches of sand or crushed sandstone.
“In 1800, the basic Smith-Cuchet-Montfort patent was granted by France and, in 1806, the Quai des Celestins filters, which operated for a half century or more, were established in Paris. James Smith, a gunsmith from Glasgow, for a short time helped Richard Younger of Edinburgh, formerly a brewer, to assemble filters, the manufacture of which Younger began in or about 1795. These filters, wrote John Wilson, in 1802, were the most remarkable of the devices proposed up to that time to purify water by the use of charcoal, in accordance with the proposals of Lowitz (see Chap. 111) and others.
Smith, having brought the Lowitz process to the attention of the French Minister of Marine “as an important secret,” says Rochon, was sent to Brest. Numberless experiments were made there in the presence of twelve representatives of different branches of the Marine Department. An official report on the experiments was made in 1798. Smith went to Paris and, with others, took out a filter patent.”
Reference: ‘Baker, Moses N. 1981. The Quest for Pure Water: the History of Water Purification from the Earliest Records to the Twentieth Century. 2nd Edition. Vol. 1. Denver, Co.: American Water Works Association, 38-9.