Trivial name for example, hydrogen ("water-producing"), oxygen ("acid-producing"), nitrogen ("soda-producing"), bromine ("stink"), and argon ("no reaction") were based on Greek roots, while the names of iodine and chlorine were derived from the Greek words for their characteristic colors. Indium, rubidium, and thallium were similarly named for the colors of particular lines in their emission spectra. Iridium, which forms compounds of many different colors, takes its name from "iris", the Latin for "rainbow". The noble gases have all been named for their origin or properties. Helium comes from the Greek "helios", meaning "sun" because it was first detected as a line in the
Westward the Course of Empire Takes Its Way imperial iconography and is regarded as a symbol of American exceptionalism and the realization of Manifest Destiny, ultimately leading to the evolution of the American Empire. The painting takes its inspiration from the closing lines of George Berkeley's "Verses on the Prospect of Planting Arts and Learning in America: <poem> Westward the course of empire takes its way; The first four Acts already past, A fifth shall close the Drama with the day; Time's noblest offspring is the last. </poem> The imagery of the pilgrim gesturing on a high rock is very similar to the 5 cent postage stamp, "Fremont