how many elements were known in 1864
So the two scientists would certainly have known each other although neither was aware of all the work done by the other. Meyer's roots, however, were firmly in Germany. Meyer was just four years older than Mendeleev, and produced several Periodic Tables between 1864-1870.His first table contained just 28 elements, organised by their valency (how many other atoms they can combine with).These elements were almost entirely main group elements, but in 1868 he incorporated the transition metals in a much more developed table.o the two scientists would certainly have known each other although neither was aware of all the work done by the other. Meyer's roots, however, were firmly in Germany. Meyer was just four years older than Mendeleev, and produced several Periodic Tables between 1864-1870.