Dmitry I. Mendeleyev

Dmitry I. Mendeleyev Scientist-encyclopaedist 1834—1907

Mendeleyev was an orphan which, however, did not prevent him from successfully finishing a gymnasium (secondary school of the highest grade preparing for universities in pre-revolutionary Russia) and, later, a pedagogical institute in St. Petersburg.

Having worked for a number of years as a teacher he later devoted himself entirely to scientific work. In 1869 the scientist published a remarkable text-book, "Fundamentals of Chemistry". While working on it, Mendeleyev discovered that the properties of the 63 chemical elements, known then, recurred periodically if they were arranged in the order of their increasing atomic weights. That uniformity was laid at the basis of his Periodic System of Elements which "reduced to order" the world of the already known chemical elements, until then chaotic, and permitted predicting the existence and properties of the as-yet unknown elements.

It is difficult to name a realm of the surrounding world which did not interest Mendeleyev. He explored oil fields and oil composition, the terrestrial atmosphere and he intrepidly performed a solo flight inside an air balloon; he was also interested in exploration of Arctic regions and developed a design for an icebreaker, he concerned himself with agriculture, studied trade and discovered the composition of a smokeless powder. For a long time the scientist headed the Main Chamber of Reference Standards and Balances and did much to develop the science of accurate measurements. Mendeleyev's 500 works fill the twenty five volumes of his Complete Works.

In 1890 he resigned from the post of a Professor of the St. Petersburg University in protest at the reprisals against the students.

In the closing years of his life Mendeleyev's activity was not as intensive. But diverse domains of science, and chemistry above all, owe their unprecedented flourishing in the 20th century in large part to his ideas and discoveries.