7. The atomic weight of an element may sometimes be amended by a knowledge of those of its contiguous elements. Thus the atomic weight of tellurium must lie between 123 and 126, and cannot be 128.
8. Certain characteristic properties of elements can be foretold from their atomic weights. (18)
On November 29, 1870, Mendeleev took his concept even further by stating that it was possible to predict the properties of undiscovered elements. He then proceeded to make predictions for three new elements (eka-aluminum, eka-boron and eka-silicon) and suggested several properties of each, including density, radii, and combining ratios with oxygen, among others. The science world was perplexed, and many scoffed at Mendeleev’s predictions. It was not until November, 1875, when the Frenchman Lecoq de Boisbaudran discovered one of the predicted elements (eka-aluminum) which he named Gallium, that Dmitri’s ideas were taken seriously. The other two elements were discovered later and their properties were found to be remarkably similar to those predicted by Mendeleev. These discoveries, verifying his predictions and substantiating his law, took him to the top of the science world. He was 35 years old when the initial paper was presented
Throughout the remainder of his life, Dmitri Mendeleev received numerous awards from various organizations including the Davy Medal from the Royal Society of England in 1882, the Copley Medal, the Society’s highest award, in 1905, and honorary degrees from universities around the world. Following his resignation from the University of St. Petersburg, the Russian government in 1893 appointed him Director of the Bureau of Weights and Measures. This was believed to have been done to keep down public disapproval of the government. Mendeleev continued to be a popular social figure until his death. In his last lecture at the University of St. Petersburg Mendeleev said:
I have achieved an inner freedom. There is nothing in this world that I fear to say. No one nor anything can silence me. This is a good feeling. This is the feeling of a man. I want you to have this feeling too – it is my moral responsibility to help you achieve this inner freedom. I am an evolutionist of a peaceable type. Proceed in a logical and systematic manner. (16)
Dmitri Mendeleev was a man who rose out of the crowd to lead his people into the future. The motto of Mendeleev’s life was work, which he stated as: Work, look for peace and calm in work: you will find it nowhere else. Pleasures flit by – they are only for yourself; work leaves a mark of long-lasting joy, work is for others. (17) On January 20, 1907 at the age of 73, while listening to a reading of Jules Verne’s Journey to the North Pole, (4) Mendeleev floated away, peacefully, for the last time.
Bibliography
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