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
Paris in the 18th century polluted since the Middle Ages by the discharge of human and animal waste, the dumping of chemicals by the tanneries, and by the decomposition of bodies in the many cemeteries not far from the river. In the 18th century the Lieutenant General of Police banned taking drinking water from between the present Quai des Celestins and the modern quai de Louvre. Average Parisians depended upon the fountains around city, which were not numerous, did not run at night, were crowded, and required a payment for each bucket taken. Parisians either collected water themselves, sent a servant, or depended upon water