Читать книгу The Times Great Lives - Anna Temkin - Страница 16

The discoverer of radium

4 July 1934

Mme Curie, whose death we announce with regret on another page, had a worldwide reputation as the most distinguished woman investigator of our times. Her claim to fame rests primarily on her researches in connection with the radioactive bodies and particularly for her discovery and separation of the new element rad-ium, which showed radiating properties to a marked degree. This was a discovery of the first importance, for it provided scientific men with a powerful source of radiation which has been instrumental in extending widely our knowledge not only of radioactivity but of the structure of atoms in general. Radium has also found an extensive application in hospitals for therapeutic purposes, and particularly for the treatment of cancerous growths by the action of the penetrating radiation emitted spontaneously from this element.

Marie Sklodowska, as she was before her marriage, was born on November 7, 1867, at Warsaw, and received her education there. She early showed a deep interest in science, and went to Paris to attend lectures in the Sorbonne. She had small financial resources, and had to teach in schools to earn sufficient money to pay her expenses. In 1895 she married Pierre Curie, a young scientist of great promise, who had already made several notable discoveries in magnetism and in the physics of crystals. Mme Curie continued her scientific work in collaboration with her husband, but the direction of their work was changed as the result of the famous discovery of Henri Becquerel in 1896, who found that the element uranium showed the surprising property of emitting penetrating types of radiation, which blackened a photographic plate and discharged an electrified body.

Examination of Pitchblende

Mme Curie made further investigations of this remarkable property using the electric method as a method of analysis. She showed that the radioactivity of uranium was an atomic property, as it depended only on the amount of uranium present and was unaffected by the combination of uranium with other elements. She also observed the striking fact that the uranium minerals from which uranium was separated showed an activity four to five times the amount to be expected from the uranium present. She correctly concluded that there must be present in uranium minerals another substance or substances far more active than uranium. With great boldness she undertook the laborious work of the chemical examination of the radioactive mineral pitchblende, and discovered a new strongly active substance which she named polonium, after the country of her birth. Later she discovered another new element, allied in chemical properties to barium, which she happily named radium. This element is present in minerals only in about one part in 3,000,000 compared with uranium, and shows radioactive properties more than a million times that of an equal weight of uranium. The Austrian Government presented Mme Curie with the radioactive residues necessary for the separation of radium in quantity, and she was in this way able to obtain sufficient material to determine the atomic weight and physical and chemical properties of the new element.

The importance of this discovery was at once recognized by the scientific world. In 1903 the Davy Medal of the Royal Society was awarded jointly to Professor and Mme Curie, while in 1904 they shared a Nobel Prize with Henri Becquerel. After the death of Pierre Curie in a street accident in Paris in 1906 Mme Curie was awarded in 1911 the Nobel Prize in Chemistry for the discovery and isolation of the element radium. In 1906 she was appointed to a special Chair in the Sorbonne and was the first woman to obtain this distinction. Later a special Radium Institute, called the Pierre Curie Institute, was founded for investigations in radioactivity, and Mme Curie became the first director. She held this post at the time of her death.

Classes at the Sorbonne

In the course of the last 20 years this institute has been an important centre of research, where students of many nationalities have carried out investigations under her supervision. Mme Curie was a clear and inspiring lecturer, and her classes at the Sorbonne were widely attended. Her scientific work was all of a high order. She was a careful and accurate experimenter, and showed marked power of critical judgment in interpreting scientific facts. She retained an enthusiastic interest in her science throughout her life, and was a regular attendant at international conferences, taking an active and valuable part in scientific discussions.

She had a deep interest in the application of radium for therapeutic work both in France and abroad, and during the War actively helped in this work. She was twice invited to visit the United States and was received with acclamation, while the women of that country presented her with a gram of radium, to allow her to extend her researches. In 1922 she was appointed a member of the International Committee for Intellectual Cooperation of the League of Nations and took an active part in their deliberations.

Mme Curie left two children. The elder, Irene, early showed marked scientific ability and married a co-worker in the Radium Institute, M. Joliot. It was a source of great satisfaction and pride to Mme Curie in her later years to follow the splendid researches made by her daughter and her husband, for they have made notable contributions to our knowledge of neutrons and transformations. During the present year, they observed that a number of elements became radioactive by bombardment with the particles from radium, and have thus opened up a new method for study of the transformation of the atoms of matter.

The many friends of Mme Curie of all nations, and the scientific world as a whole, will greatly lament the removal of one who was held in such great honour for her splendid discoveries in science, and one who by strength of character and personality left a deep impression on all those who met her.