Gas dioxide, and air expand to the same extent over the same 80 kelvin interval. He noted that, for an ideal gas at constant pressure, the volume is directly proportional to its temperature: In 1802, Joseph Louis Gay-Lussac published results of similar, though more extensive experiments. Gay-Lussac credited Charles' earlier work by naming the law in his honor. Gay-Lussac himself is credited with the law describing pressure, which he found in 1809. It states that the pressure exerted on a container's sides by an ideal gas is proportional to its temperature. In 1811, Amedeo Avogadro verified that equal volumes of pure
Same-sex marriage law in the United States by state Puerto Rico." Texts: § 31. Nature of marriage. "Marriage is hereby declared to be a civil contract which may be entered into between a male and a female in accordance with law." State by state: Same-sex marriage law in the United States by state This article summarizes the same-sex marriage laws of states and similar jurisdictions in the United States. Via the case "Obergefell v. Hodges" on June 26, 2015, the Supreme Court of the United States legalized same-sex marriage in a decision that applies nationwide, with the possible exception of American Samoa and some tribal jurisdictions. Same-sex marriages are