Many substances in nature are a mixture of two or more components. These mixtures can be separated into individual comonents by physical separation processes (for example by filtration). This experiment demonstrates how a mixture of salt and sand can be separated into its components. This involves adding some water to a mixture of solid salt and solid sand to make a suspension which is then poured through a filter paper. The sand will remain in the filter while the salt will dissolve into a solution which passes through the filter into a beaker underneath.