Leipzig, Karl W. Hiersemann, 1911. Gr.-8°. XIII (1), 275 (1) S., (4) Bl. (Verlagsanzeigen). Mit 64 Tafeln. Orig.-Leinenband. = "Kunstgeschichtliche Monographien", Band XV.
Papier durchgehend gebräunt. Vorderer Innenfalz angeplatzt.
2. Bruxelles, Hayez, Imprimeur de l'Académie, 1903, in-8°, 668 pp, sewn, original printed wrapper (back wrapper is missing, last leaf with some damage but no loss of text.). Published as a ''Mémoire Couronné de l'Académie Royale des Sciences...de Belgique''. Translation in French of a scientific treatise in German by Prof. Curt Weigelt on water treatment and improvement of the water quality in rivers. The study contains a large numbers of test on the influence of water polluting chemicals on fresh water fishes , mainly trout. Very early study on ecology, environmental protection.