Period 6 element devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light. Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The
Fire (classical element) temperament (of a person dominated by the yellow bile humour); the masculine; and the eastern point of the compass. In alchemy the chemical element of sulfur was often associated with fire and its alchemical symbol and its symbol was an upward-pointing triangle. In alchemic tradition, metals are incubated by fire in the womb of the Earth and alchemists only accelerate their development. Agni is a Hindu and Vedic deity. The word "agni" is Sanskrit for fire (noun), cognate with Latin "ignis" (the root of English "ignite"), Russian "огонь" (fire), pronounced "agon". Agni has three forms: fire, lightning and the sun.