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
Period 4 element can also be found in semiconductors. Germanium (Ge) is an element in period 4, between gallium and arsenic. Germanium, like silicon above it, is an important semiconductor and is commonly used in diodes and transistors, often in combination with arsenic. Germanium is fairly rare on Earth, leading to its comparatively late discovery. Germanium, in compounds, can sometimes irritate the eyes, skin, or lungs. Arsenic (As) is an element in period 4, between germanium and selenium. Arsenic, as mentioned above, is often used in semiconductors in alloys with germanium. Arsenic, in pure form and some alloys, is incredibly poisonous to all