TYSON, Elisha, philanthropist, born in Montgomery county, Pennsylvania, in 1749; died in Baltimore, Maryland, 16 February, 1824. He was a member of the Society of Friends, and an early member of the Maryland society for the abolition of slavery, appeared frequently before the judicial tribunals in behalf of negroes, and procured the passage of several laws to ameliorate their condition, in 1818 he retired from business to devote his attention to the abolition movement, and established the Protection society of Maryland, to insure the colored population of the state the enjoyment of their legal privileges. See his "Life," by a citizen of Baltimore (Baltimore, 1825).--His grandson, Philip Thomas, chemist, born in Baltimore, Maryland, 23 June, 1799; died there. 16 December, 1877, was educated in his native city. At the beginning of the gold fever he went to California, and there made numerous geological researches. On his return he published "Geology and Industrial Resources of California" (Baltimore, 1851). In 1856 he was appointed state agricultural chemist, which place he held until 1860, and in that capacity made two biennial reports that were published by the house of delegates of Maryland (2 vols., Annapolis, 1860-'2). He was first president of the Maryland academy of sciences, and contributed papers to its proceedings.