ROTH, JUSTUS LUDWIG ADOLF (1818-1892), German geologist and mineralogist, was born at Hamburg on the 15th of September 1818. In 1867 he was appointed professor of mineralogy at the university of Berlin. He may be regarded as one of the founders of petrographical science. In his published papers he dealt with metamorphism and crystalline schists, discussed the origin of serpentine, and wrote on Vesuvian rocks and on Ponza Island. His separate works included Der Vesuv und die Umgebung von Neapel (1857); Beiträge zur Petrographie der plutonischen Gesteine (1869-84); Allgemeine und chemische Geologie (3 vols., 1879-93); and Über die Erdbeben (1882). He died at Berlin on the 1st of April 1892.