John Alexander Newland proposed the property of every eight elements being similar to the 1st element. This proposal is known as the Law of Octaves.

Explanation:
The Law of Octaves is a concept in chemistry that was proposed by John Alexander Newland in 1864. He observed that when elements are arranged in order of increasing atomic mass, every eighth element exhibits similar properties to the first.

Arrangement of Elements:
Newland arranged elements in the order of their increasing atomic masses and grouped them into rows of seven elements each. He noticed that the eighth element in each row showed similarities to the first element of the next row.

Example:
For example, if we take the elements from lithium (Li) to fluorine (F), we can see a pattern:
- Li, Be, B, C, N, O, F
- The eighth element, F, shows similar properties to the first element, Li.

Limitation:
However, Newland's Law of Octaves had a limitation. It failed to accommodate all the known elements at that time. The pattern broke down after calcium (Ca). Elements with similar properties were not always found at regular intervals of eight, making the law incomplete.

Significance:
Even though the Law of Octaves was not entirely accurate, it played a crucial role in the development of the periodic table. It helped scientists recognize the periodicity of elements and laid the foundation for the subsequent development of the periodic table by Dmitri Mendeleev and other scientists.

Mendeleev's Periodic Table:
Dmitri Mendeleev expanded on Newland's work and created the modern periodic table. He arranged the elements in order of increasing atomic mass and observed that elements with similar properties occurred at regular intervals. Mendeleev's periodic table provided a more comprehensive and accurate representation of the elements and their properties.

In conclusion, John Alexander Newland proposed the Law of Octaves, which stated that every eighth element exhibits similar properties to the first element when arranged in order of increasing atomic mass. Although this law had limitations, it played a crucial role in the development of the periodic table. Mendeleev's periodic table, based on the concept of periodicity, provided a more accurate representation of the elements.