What were the limitations of Newlands’ Law of Octaves?

Explanation

Newlands' law of octaves for the classification of elements had the following limitations:
(i) Newlands' law of octaves was applicable to the classification of element up to caclium only. After calcium, every eight element did not posses the properties similar to that of the first element. Thus, Newlands' law of octaves worked well with lighter elements only.
(ii) Newlands assumed that only 56 element existed in nature and no more elements would be discovered in the future. But later on several new elements were discovered whose properties did not fit into Newlands' law of octaves.
(iii) In order to fit elements into his table, Newlands put even two element together in one slot and that too in the column of unlike element having very different properties. For example, the two elements cobalt (Co) and nickel (Ni) were put together in just one slot, and that too in the column of elements like fluroine, chlorine and bromine which have very different properties from these elemnets.