Грамматика: Времена Indefinite

(passive voice)

D. I. Mendeleyev

D. I. Mendeleyev, the great Russian scientist, was born in Tobolsk in 1834. After finishing school at the age of 16 he went to St. Petersburg and entered the Pedagogical Institute. He graduated from the Institute in 1855. In 1866 Mendeleyev was appointed professor at the University where he gave a course of lectures on chemistry. His lectures were always listened to with great interest and attention. Even in a class of two hundred students everyone was able to follow his discussions from the beginning to the end.

Interesting experiments were made in his classes. Both he and his student-assistants worked long hours in preparing the demonstrations so that all would go well¹.

At the University Mendeleyev taught classes in the morning. In the afternoon he made experiments in his two-room laboratory. At night Mendeleyev spent much of his time working with the cards on which he put down information about each of the chemical elements.

Mendeleyev made thousands of experiments with his own hands. He made thousands of calculations, wrote a lot of letters, studied many reports. Everything in the world that was known about the chemical elements Mendeleyev knew. For months, for years he searched for missing data². All those data were being brought together and grouped in a special way. In 1869 the description of more than 60 elements was completed, and Mendeleyev published his Periodic Table.

The Periodic Table is spoken of as the beginning of a new era in chemical thought.

In addition to this work Mendeleyev paid much attention to many subjects of an applied chemical nature He was the first to put forward the idea of studying the upper layers of the atmosphere.

Mendeleyev was elected member of many academies abroad. He died in February 1907 at the age of 75.

Mendeleyev's Periodic Table

D. I. Mendeleyev was the first to discover the law of dependence of the properties of the elements upon their atomic weights. (The atomic weight is the only property which is unaffected by chemical changes).

Mendeleyev suggested a system of classification in which the elements are arranged in the order of increasing atomic weights. The main idea of the Periodic system is that of the periodic repetition of properties with the increase of the atomic weights.

But Mendeleyev did more than that. He predicted the existence of unknown elements which he called ekaboron, ekaaluminum and ekasilikon and for which he left gaps in his table. He even described the properties of these elements.

Late one night in November 1875 while he was writing an article he heard someone running to his study. He waited... The door opened. It was professor Menshutkin, Mendeleyev's friend.

"Mitya!" he cried. "Mitya! They have found ekaaluminum! Perfect prediction! I think they are going to call it "Gallium." Here - read!" And he gave Mendeleyev the article of the Paris Academy of Sciences.

The discovery of gallium was followed by the discovery of scandium (ekaboron) in 1879 and the discovery of germanium (ekasilicon) in 1886. No gaps are left now for undiscovered elements.

With the Periodic Table at his disposal a chemist needn't learn all the properties of all the elements. When he knows the properties of one or two elements in each group, the Table will give him a very good idea of what to expect of the other elements.

The Table is, was, and will be referred to and used in solving research problems of industrial importance.

Notes

1 so that all would go well	– с тем, чтобы все было хорошо
2 data	– сведения

Vocabulary Exercises