Wednesday, 6 March 2019


On this day (Old Style, 18 March 1869 on the Gregorian Calendar—it’s nice that this anniversary comes around again), one hundred fifty years ago, Professor Dmitri Mendeleev having previously formulated the Period Laws formally presented his Periodic Table as a way of arranging and understanding the elements to the Russian Chemical Society, titling his presentation The Dependence Between the Properties of the Atomic Weights, positing that the element arranged according to their mass exhibit an apparent periodicity of properties and to expect the discovery of yet unknown elements from gaps in his schema.