Bronze and brass ornamental work a smaller or greater amount of zinc. In early times this metal seems to have been sparingly employed, but from the Middle Ages onward the industry in brass was a very important one, carried out on a vast scale and applied in widely different directions. The term "latten", which is frequently met with in old documents, is rather loosely employed, and is sometimes used for objects made of bronze; its true application is to the alloy we call brass. In Europe its use for artistic purposes centered largely in the region of the Meuse valley in south-east Belgium, together with
Group 6 element 1924. For about a century after its isolation, molybdenum had no industrial use, owing to its relative scarcity, difficulty extracting the pure metal, and the immaturity of the metallurgical subfield. Early molybdenum steel alloys showed great promise in their increased hardness, but efforts were hampered by inconsistent results and a tendency toward brittleness and recrystallization. In 1906, William D. Coolidge filed a patent for rendering molybdenum ductile, leading to its use as a heating element for high-temperature furnaces and as a support for tungsten-filament light bulbs; oxide formation and degradation require that moly be physically sealed or held in an