Dmitri Mendeleyev's Periodic Law

        Dmitri Mendeleyev was a Russian chemist who found periodic law. As a proffesor Mendeleyev taught first at the St. Petersburg Technological Institute and then at the Universty of St. Petersburg where he remained trough 1890. Realizing he was in need of quality textbook to cover the subject of inorganic chemistry, he put together one of his own The Principles of chemistry.

        While he was resarching and writing that book in the 1860s, Mendeleyev made the discovery that led to his most famous achievement. He noticed certain recurring patterns between different groups of elements and using existing knowledge of the elements' chemical and physical properties he was able to make further connections. He systematically arranged the dozens of known elements by atomic weight in a grid-like digram; following this system he could even predict the qualities of still-unknown elements. In 1869, Mendeleyev formally presented his discovery of the periodic law to the Russian Chemical Society.