The first publication of the Periodic Table of the Elements, the backbone of many studies of chemistry, came on February 17, 1869, from the hand of Russian chemist Dmitri Mendeleev.

The first draft was in Mendeleev's own handwriting and contained 63 elements–all that known to exist at the time. (The current total is nearly twice that.)

Mendeleev was a student at Germany's Heidelberg University and then a professor at Russia's St. Petersburg University. He pursued his idea grouping elements according to their atomic weights for some time before settling on the form that is now familiar around the world.

He started by writing on a card the name, mass, and property of an element. He then played the equivalent of solitaire, shuffling often, until he found an order that, to him, made sense. It might seem simple now because modern chemistry students and aficionados grew up the Periodic Table as it is, but Mendeleev found his way to his solution, in the end, by dreaming. He awoke from a deep sleep and quickly arranged the element cards in the same columns in which we know now, with the lowest atomic weight at the top of a column, and then elements with similar properties in the same row across.

Mendeleev was far-sighted enough to leave gaps for undiscovered elements, even predicting the properties of three of them: gallium, germanium, and scandium–all of which were discovered within three years of the publication of the first draft of the Periodic Table; they matched Mendeleev's predictions.

Mendeleev built on the work of others in crafting his Periodic Table. Earlier chemists discovered elements and/or went about trying to classify them. Among them were Hennig Brand, Alexandre-Emile Béguyer de Chancourtois, Johann Wolfgang Döbereiner, Antoine-Laurent de Lavoisier, Julius Lother Meyer, John Newlands, and William Odling.

Scientists have discovered more elements in the 150 years since Mendeleev first published his Periodic Table. As late as 1900, the Periodic Table had 83 elements on it.

For more on the history of the discovery of chemical elements represented on the Periodic Table, see especially the site from the Royal Society of Chemistry.