MANSFIELD, Charles B., chemist, born in Hampshire, England, in 1819: died in London, England, in February, 1855. He was the son of a clergyman, and was educated at Winchester and Clare Hall, Cambridge. From the time he left the university he devoted himself to chemistry and dynamics, finding recreation in ornithology, geology, mesmerism, and even "old magic." After many struggles he succeeded, in 1855, in obtaining a patent for a valuable chemical discovery, and while making experiments he met with an accident that caused his death. In May, 1852, he sailed for Paraguay, and was one of the first Englishmen to enter the country after the fall of Juan Manual de Rosas and the British government had decided to recognize its independence. After his death Mr. Mansfield's private letters, descriptive of his journey, were published under the title of "Paraguay, Brazil, and the Platte," with a memoir by the Reverend Charles Kingsley (London, 1856). "The Constitution of Salts." and other of his treatises, have also been published posthumously.