In 1869, Dmitri Mendeleev put forward another periodic table. This table was published only 5 years after Newlands' and also organised the elements in order of relative atomic mass. Mendeleev took Newlands' ideas and furthered them, making the connection between both chemical and physical properties and their atomic masses. This let him see that these properties were related in a 'periodic' way and ordered the table using periods - aka vertical columns (jan 1, 1869 – 23h 59min, dec 31, 1869 y)
Added to timeline:
Date:
jan 1, 1869
23h 59min, dec 31, 1869 y
~ 12 months