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 of "Pavan v. Smith" that under their decision in "Obergefell", same-sex couples must be treated equally to opposite-sex couples in the issuance of birth certificates. In December 2016, the Supreme Court of Arkansas upheld a state law only allowing opposite-sex couples to be automatically listed as parents on their children's birth certificates, while prohibiting same-sex couples from being allowed the same on an equal basis. The Supreme Court summarily reversed the Arkansas Supreme Court, finding that the disparity in treatment violated their decision in "Obergefell". The Supreme Court decision legalizing same-sex marriage in the states and territories did not legalize