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 Republic of Ireland Affairs, Katherine Zappone, on 18 October and the law went into effect the following day. 91 same-sex marriages were performed between 16 November and 31 December 2015, 47 of them were between men and 44 were between women. A few days ahead of the anniversary of the Marriage Equality referendum on 22 May 2016, the Department of Social Protection released statistics on the number of same-sex marriages that had taken place since November 2015. A total of 412 same-sex marriages were performed in those six months. 1,082 same-sex couples wed in Ireland in the one year following the "Marriage Act"'s