What are the drawbacks of Newland's law of octaves

What are the drawbacks of Newland's law of octaves? 

Answer: Following are the major drawbacks: 

1. Worked well with lighter elements (up to Calcium). After that elements in eighth column did not possess properties similar to element in first column. 

2. Newland assumed only 56 elements existed so far. Later new elements were discovered which did not fit into octaves table. 

3. Newland adjusted few elements in a same slot though their properties were quite different. E.g. Cobalt and nickel are in the same slot and these are placed in the same column as fluorine, chlorine and bromine which have very different properties than these elements. 

Iron, which resembles cobalt and nickel in properties, has been placed far away from these