Williamson is credited for his research on the formation of unsymmetrical ethers by the interaction of an alkoxide with a haloalkane, known as the Williamson ether synthesis. He regarded ether and alcohol as substances analogous to and built up on the same type as water, and he further introduced the water-type as a widely applicable basis for the classification of chemical compounds. The method of stating the rational constitution of bodies by comparison with water he believed capable of wide extension, and that one type, he thought, would suffice for all inorganic compounds, as well as for the best-known organic ones, the formula of water being taken in certain cases as doubled or tripled.[5][6][7]