By Catherine Hamlin
At University, Dmitri worked under Aleksandr A. Voskresenskii, who the Russians call the grandfather of Russian chemistry. His studies of the isomorphism led him to observe the similarity of the crystalline structures of related elements, which aided him in constructing the periodic table. When he graduated in 1885 he won a gold medal for being first in his class.
Not only did Dmitri invent the Periodic Table, he also made other important contributions to chemistry. He invented pyrocollodion, a kind of smokeless powder based on nitrocellulose. During his stay at Heidelberg University, he designed the Mendeleev pyknometer for determining the specific gravity of liquids. Dmitri accepted the chair of technology at the Technological Institute of St. Petersburg in 1864, received his doctorate in chemistry in 1865, filled the chair of inorganic chemistry at the University of St. Petersburg, which he retained for the next 23 years, in 1867, and helped found the Russian Chemical Society in 1868.
"I saw in a dream a table where all elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper, only in one place did a correction later seem necessary" - Dmitri Mendeleev