Ellen S. Richards Monographs No. 2
Published by Vassar College
The Discovery
of
Radium
It is myearnest desire that some of you shall carry onthis scientific work and will keep for yourambition the determination to make apermanent contribution to scienceM. Curie
Address by
Madame M. Curie
at Vassar College
May 14, 1921
PREFATORY NOTE
In her recent visit to America, Madame Curieconferred a special honor upon Vassar College bydelivering in the chapel on the evening of May fourteenththe only extended address which she made inthis country. In a simple, straightforward way shetold the story of her great achievement. One realizedhow, closely environed by all the great realities of humanexperience, in the face of tremendous difficulties andwith limited resources, she had pursued undaunted hersearch for truth.
The discovery of radium gave Madame Curie immediatedistinction among scientists on account of theextremely significant contribution she thereby made tothe great ultimate problem of physical science, theconstitution of matter. The striking properties possessedby radium gave to its discovery a world-wideinterest, all the more intense because of the hope whichwas inspired by the possible healing qualities of theradiations from this new element.
That hope is being realized in large measure. It istherefore fitting that this address should have beengiven by Madame Curie at Vassar and that it shouldnow be circulated among the members of the collegeunder the foundation in memory of Ellen S. Richards,who devoted her life to the public health.
Edna CarterChairman of the Department of Physics.
THE DISCOVERY OF RADIUM
I could tell you many things about radium and radioactivityand it would take a long time. But as we can not do that, Ishall only give you a short account of my early work aboutradium. Radium is no more a baby, it is more than twentyyears old, but the conditions of the discovery were somewhatpeculiar, and so it is always of interest to remember them andto explain them.
We must go back to the year 1897. Professor Curie and Iworked at that time in the laboratory of the school of Physicsand Chemistry where Professor Curie held his lectures. I wasengaged in some work on uranium rays which had been discoveredtwo years before by Professor Becquerel. I shall tellyou how these uranium rays may be detected. If you take aphotographic plate and wrap it in black paper and then on thisplate, protected from ordinary light, put some uranium saltand leave it a day, and the next day the plate is developed,you notice on the plate a black spot at the place where theuranium salt was. This spot has been made by special rayswhich are given out by the uranium and are able to make animpression on the plate in the same way as ordinary light.You can also test those rays in another way, by placing themon an electroscope. You know what an electroscope is. Ifyou charge it, you can keep it charged several hours and