Ernst Chladni at the understanding of electron orbitals. Since at least 1738, a musical instrument called a "Glasspiel" or "verrillon", created by filling beer glasses with varying amounts of water, was popular in Europe. The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music". Benjamin Franklin was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the glass armonica, in 1762. Franklin's armonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the "euphon" (not to
Opaline glass from 1800 to the 1890s, though it reached its peak of popularity during the reign of Napoleon III in the 1850s and 1860s. The glass is opaque or slightly translucent, and can appear either white or brightly colored in shades of green, blue, pink, black, lavender and yellow. The glass has a high lead content which defined it as "demi-crystal" or semi-crystal. The primary influences on this style of glass were 16th century Venetian milk glass, and English white glass produced in 18th century Bristol. Many different pieces were produced in opaline glass, including vases, bowls, cups, coupes, decanters, perfume