Although Grattan had a profound contempt for Emmet's political understanding, describing him as a quack in politics who set up his own crude notions as settled rules, Emmet was among the more prudent of the United Irishmen on the eve of the rebellion.
The latter process, which was known to Basil Valentine, was commercially applied by the quack doctor, Joshua Ward (1685-1761), of Twickenham, England, to the manufacture of the acid, which was known as "oil of vitriol made by the bell" or per campanum.
ALEXANDRE AUGUSTE LEDRU-ROLLIN (1807-1874), French politician, was the grandson of Nicolas Philippe Ledru, the celebrated quack doctor known as "Comus" under Louis XIV., and was born in a house that was once Scarron's, at Fontenay-aux-Roses (Seine), on the 2nd of February 1807.
Hence the modern sense of empirical as applied to the guess work of an untrained quack or charlatan.
An aqueous solution of ferric chloride is used in pharmacy under the name Liquor ferri perchloridi; and an alcoholic solution constitutes the quack medicine known as " Lamotte's golden drops."