Noble gas to be retained. Neon, argon, krypton, and xenon also form clathrate hydrates, where the noble gas is trapped in ice. Noble gases can form endohedral fullerene compounds, in which the noble gas atom is trapped inside a fullerene molecule. In 1993, it was discovered that when , a spherical molecule consisting of 60 carbon atoms, is exposed to noble gases at high pressure, complexes such as can be formed (the "@" notation indicates He is contained inside but not covalently bound to it). As of 2008, endohedral complexes with helium, neon, argon, krypton, and xenon have been obtained. These compounds
Copia: Foundations of the Abundant Style 11 separate methods of using abundant subject matter. Here Erasmus uses a more dialectical approach, and typically gives a few lines of theory followed by many illustrations from classical sources. Erasmus purpose was to contribute to the existing scholarship on style. To that end, he put forth in "De Copia" that style must be abundant in order to be effective, and that the abundance consists of two primary elements: variety of expression and variety of subject matter. Variety, he says, “is so powerful in every sphere that there is absolutely nothing, however brilliant, which is not dimmed if not commended