How about Antoine Lavoisier and Johann Wolfgang Döbereiner? are not they contributing also in the elemental periodic system? tell me about them too, in 1789 Lavoiser published a list of 33 chemical elements. He classified them into gases, metals, non-metals, and soil. Chemists spent a century searching for a more adequate classification scheme. Futhermore In 1829, Johann Wolfgang Döbereiner observed that many elements which can be grouped into triads based on their chemical properties.