On the wall of every school chemistry laboratory is a poster of the periodic table of elements. It has been the go-to reference on chemical elements for almost 150 years. Yet while the Russian chemist Dmitri Mendeleev is often credited with finding the rules behind the block-like patterns of elements, he was hardly alone: others had found them some years before, but failed to win recognition.
One of these scientists was John Newlands, an English chemist who in the mid-1860s pointed out that elements with similar properties lie close together if arranged according to their atomic mass. But in describing his findings to fellow scientists, he drew parallels with octaves of musical notes, which prompted howls of derision. Newlands’ discovery had in any case been presaged by the work of another English chemist, William Odling, but he too failed to garner much interest.
Mendeleev’s claim to fame lies in the fact that he realised that the patterns were more complex than others had realised, leading to some columns on the table being longer than others. He also suspected that gaps within the resulting blocks implied the existence of as-yet undiscovered elements, and bravely attempted to predict their properties. His confidence was vindicated with the discovery of gallium, germanium and scandium, ensuring his place among the great names of 19th-Century science.