Newlands law of octaves ordered elements categorically according to their atomic mass and their properties.
It was close but had problems:
*some elements in the same group had contrasting properties i.e titanium and carbon
*Oxygen - a gas - was in the same group as iron - a solid, transition metal
Like Newlands ordered elements in relation to atomic mass and their properties.
However he left gaps where elements propeties didn't reflect one another.
This meant that when new elements were found they could be checked against mendleevs table which proved to be correct.