What did Dmitri Mendeleev build on when he was making his own Periodic Table?
As seen in the timeline on "Key dates in the Periodic Table's History," scientists had already been looking for patterns and developing tables prior to Mendeleev unveiling his periodic table in 1869. Some examples are are below.
In 1789, Antoine Lavoisier wrote an in depth list of the 33 elements which were known at the time. He grouped them into four groups (this can be seen in the image to the right). The four groups were gases, metals, nonmetals and earths.
John Newlands made this table in 1865. He arranged all the known elements into 7 groups and was able to identify patterns.
Lothar Meyer was another scientist who attempted to look for relationships between atoms. In his table from 1868, he arranged the elements in order of atomic weight and discussed relationships between properties of elements and atomic weight.