Graham's law has come to denote an important class of finely divided materials. Around the time Graham did his work, the concept of molecular weight was being established largely through the measurements of gases. Daniel Bernoulli suggested in 1738 in his book Hydrodynamica that heat increases in proportion to the velocity, and thus kinetic energy, of gas particles. Italian physicist Amedeo Avogadro also suggested in 1811 that equal volumes of different gases contain equal numbers of molecules. Thus, the relative molecular weights of two gases are equal to the ratio of weights of equal volumes of the gases. Avogadro's insight together with
Same-sex marriage in the United States In 2015, John Lewis, a leader of the civil rights movement and a chairman of the SNCC, welcomed the outcome of the landmark civil rights case of "Obergefell v. Hodges" in which the Supreme Court of the United States struck down all state bans on same-sex marriage, stating that "races don't fall in love, genders don't fall in love—people fall in love". The NAACP, the leading African-American civil rights organization, has pledged its support for gay rights and same-sex marriage, stating that they "support marriage equality consistent with equal protection under the law provided under the Fourteenth Amendment of the