the most learned woman of her age and the only woman who understood his works. In translating his brilliant work "Mécanique Celeste," she greatly popularized its form. Its publication in 1831 under the title of "The Mechanism of the Heavens" at once made her famous. Her own works: "Connections of Physical Science," "Physical Geography" and "Molecular and Microscopic Science" have been declared masterworks, distinguished by a clear and crisp style, and the underlying enthusiasm for the subject.
In the history of chemistry the name of Marie Curie will be forever connected with the wonderful discovery of Radium and Radio-activity. Born on November 7, 1867, at Warsaw as Marja Sklodowska she came to Paris in 1 888 and studied at the Faculté des Sciences. In 1895 she married Professor Pierre Curie and joined him in his chemical investigations. It was in 1898 that she published a most valuable work on metals in solution. Her investigations in collaboration with her husband led to the discovery of two new bodies: Polonium and Radium, which are found in certain minerals, especially in pitch blende in a state of extreme solution; as a matter of fact, to the extent only of a few decigrammes to the ton of mineral for Radium, and much less in the case of Polonium. The separation of these elements presented extreme difficulties.
Further investigations led to the observation of most interesting phenomena in connection with these bodies—chemical effects, luminous effects, effects of heating, etc. New realms of science were disclosed—the science of Radio-active phenomena. In recognition of these discoveries in 1903 the Nobel Prize was awarded to Professor Curie and his wife. And when Mrs. Curie, after the tragic death of her husband, accomplished the "isolation" of Radium and also determined its atomic weight, she was awarded the Nobel Prize for a second time in 1911. At present Mrs. Curie is Director of the Physico-Chemical Department of the University of Paris.
For valuable research work in bacteriology Dr. Rhoda Erdmann, a former assistant of the famous professor Robert Koch in Berlin, became most favorably known. Having published several excellent treatises on the amoeba and protozoa, she followed in 1913 a call to the Sheffield-Institute of Yale University.
In the wide fields of archæology and ethnology likewise several women have achieved remarkable results. Among those scientists who devoted themselves to the study of archæology and the ancient history of America the name of Zelia Nuttall is well known. She is the author of many interesting essays on the relics left by the Aztecs, Toltecs, and Mayas. Science is also indebted to her for the so-called "Codex Nuttall," now preserved in the Peabody-Museum at Cambridge, Mass.
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