Brass Late Roman. Latten is a term for decorative borders and similar objects cut from sheet metal, whether of brass or bronze. Aquamaniles were typically made in brass in both the European and Islamic worlds. The cementation process continued to be used but literary sources from both Europe and the Islamic world seem to describe variants of a higher temperature liquid process which took place in open-topped crucibles. Islamic cementation seems to have used zinc oxide known as "tutiya" or tutty rather than zinc ores for brass-making, resulting in a metal with lower iron impurities. A number of Islamic writers and
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