Explain 'Newland's law of Octaves'. Why was the law discarded?

According to Newland's law of octaves, when elements are arranged by increasing atomic mass, the properties of every eighth element starting from any element are a repetition of the properties of the starting element.

Reasons for discarding the Newland's law of Octaves:

1. This classification did not work with heavier elements i.e., those lying beyond Calcium. As more and more elements were discovered, they could not be fitted into Newland's Octaves.
2. Newland adjusted two elements Cobalt (Co) and Nickel (Ni) in the same slot, and these were placed in the same column as fluorine, chlorine and bromine which have very different properties than these elements.
3. Iron, which resembles cobalt and nickel in properties has been placed far away from these elements.