History of chemistry 1808, certain of his central ideas were soon adopted by most chemists. However, uncertainty persisted for half a century about how atomic theory was to be configured and applied to concrete situations; chemists in different countries developed several different incompatible atomistic systems. A paper that suggested a way out of this difficult situation was published as early as 1811 by the Italian physicist Amedeo Avogadro (1776-1856), who hypothesized that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules, from which it followed that relative molecular weights of any two gases are the same as
History of same-sex marriage in the United States voters approved a constitutional amendment banning same-sex marriage as well as all other types of same-sex unions. In the regular November 2012 elections, voters for the first time approved the legalization of same-sex marriage by popular vote in three states: Maine, Maryland, and Washington. Maine's law took effect on December 29, 2012. Maryland started allowing same-sex marriages on January 1, 2013, In Washington state, the first licenses were distributed on December 6, with the first marriages on December 9 following the mandatory three-day waiting period. In the same election, Minnesota rejected a constitutional ban on same-sex marriage. On June 26,