is Eilhard Mitscherlich's birthday. Mitscherlich was a German chemist who introduced the idea of isomorphism. He theorized that chemical substances that crystallize together into a solid will typically have similar chemical formulas. Isomorph compounds can substitute each other when crystallizing and the shape of the crystal will not change. Another property of isomorphic compounds concerns the relative sizes and positions of the ions and cations of the minerals. Isomorphic minerals will have the same coordination and relative ion sizes of each component. This property was later used by Jöns Jacob Berzelius
in his attempt to create a table of elements based on atomic weights.
Mitscherlich was also the chemist who discovered permanganic and silenic acids and made several contributions to the understanding of arsenic, phosphorus and benzene derivatives. Find out what else occurred on this day in science history