John Alexander Reina Newlands (26 November 1837 – 29 July 1898) was an English chemist who worked on the development of the Periodic Table.
Newlands was born in London and was the son of a Scottish Presbyterian minister and his Italian wife. He was home schooled by his father, rather than going to a normal school. He went on to study at the Royal College of Chemistry but was also interested in social reform, and in 1860, he served as a volunteer with Giuseppe Garibaldi in his campaign to unify Italy. Returning to London, he set up in practice as an analytical chemist in 1864, and in 1868 became chief chemist in James Duncan's London sugar refinery, where he introduced a number of improvements in processing. Later he left the refinery and again set up as an analyst with his brother Benjamin.
Newlands was the first person to devise a Periodic Table of elements arranged in order of their relative atomic weights. Continuing Döbereiner’s work with triads and J. B. Dumas' families of similar elements, in 1865 he published his law of octaves which states that "any given element will exhibit analogues behaviour to the eighth element following it in the table". Newlands’ arrangement showed all known elements arranged in seven groups which he likened to the octaves of music. The elements are ordered by atomic weights that were known at the time. They were numbered sequentially to show the order of atomic weights. In Newlands’ table periods and groups are shown going down and across the table, respectively – the opposite from the modern periodic table.
The incompleteness of a table he drew up in 1864 alluded to the possible existence of additional, undiscovered elements. For example, he predicted the existence of germanium.
At the time, his law of octaves was ridiculed by his contemporaries and the Society of Chemists did not accept his work for publication.
In 1894, Newlands had a child by the name of Christopher Maddocks Newlands.
After Dmitri Mendeleev and Lother Meyer received the Davy Medal from the Royal Society for their later 'discovery' of the Periodic Table, Newlands fought for recognition of his earlier work; he eventually received the Davy medal in 1887.
Newlands died on 29 July 1898 at his home in Lower Clapton, London, and was buried at West Norwood Cemetery. His business was continued after his death by his younger brother, Benjamin Edward Reina Newlands (1842–1912).