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Bertram Borden Boltwood papers

Call Number: MS 90

Scope and Contents

Bertram Borden Boltwood (1870-1927) is best known for his work in the field of radioactivity. Important contributions by Boltwood in this field include: the discovery of a new chemical element, ionium; the proof that uranium, ionium, and radium are genetically related; the proof that certain elements could not be chemically separated which led to the discovery of isotopes by Frederick Soddy and Kasimir Fajans; the proof that lead is the end product of the uranium-radium series; the development of the method used to determine the age of the earth, based on the ratio of lead to uranium; and the proof that actinium is a genetic descendant of uranium in a different line than radium. Much of Boltwood's work in radioactivity seems to have been inspired by suggestions made by Ernest Rutherford (Lord Rutherford), the father of atomic physics. In turn, Boltwood's proofs of various radioactive theories supported Rutherford's findings and provided a basis for further discoveries. The Boltwood-Rutherford correspondence, consisting of approximately 125 letters dating from 1904 to 1924, forms an important part of these papers.

Correspondence and writings make up the bulk of the Bertram Borden Boltwood Papers. Besides the correspondence with Lord Rutherford, there is, correspondence with other notable scientific figures including: Frederick Soddy, pioneer in the field of isotopes; Otto Hahn, discoverer of nuclear fission; Stefan Meyer, physicist and director of the Radium Institute in Vienna; Ellen Gleditsch, Norwegian chemist who, under Boltwood's direction, determined an accurate method for determining the half-life of radium; Howard A. Kelly, pioneer in the application of radium to malignancies; and physicists Hans Geiger, Robert W. Wood, A. S. Eve and J. C. McLennan. Boltwood's correspondence also includes letters of advice as chemical consultant to miners, prospectors and chemical manufacturers.

The writings of Bertram Borden Boltwood include laboratory notebooks which cover the years 1892-1893, 1896-1900, 1904-1917, 1924, and 1926. There are also drafts of lectures on radioactivity, as well as several copies of scientific reports stemming from Boltwood's work as a consulting chemist. Four drafts of scientific papers attributed to Boltwood are found in the papers. They deal generally with the disintegration products of uranium.

The section on writings of others includes four papers by Lord Rutherford and "The Life of Radium" by Ellen Gleditsch.

See: Rutherford and Boltwood: Letters on Radioactivity. Edited by Lawrence Badash. Yale University Press, 1969.


  • 1890-1932


Conditions Governing Access

The materials are open for research.

Conditions Governing Use

Unpublished materials authored or otherwise produced by the creator(s) of this collection are in the public domain. There are no restrictions on use. Copyright status for other collection materials is unknown. Transmission or reproduction of materials protected by U.S. Copyright Law (Title 17, U.S.C.) beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owners. Responsibility for any use rests exclusively with the user.


Arranged in three series: I. Correspondence. II. Writings. III. Subject File.


3 Linear Feet (8 boxes, 1 folio)

Language of Materials


Catalog Record

A record for this collection is available in Orbis, the Yale University Library catalog

Persistent URL


Correspondence, laboratory notebooks, lectures, and other writings of B.B. Boltwood, scientist and professor of radiochemistry at Yale, best known for his early work in the study of radiation. Of particular note is Boltwood's extended correspondence with Lord Rutherford, the father of atomic physics.

Biographical / Historical

Bertram Borden Boltwood (1870-1927), born in Amherst, Massachusetts, was the son of Thomas Kast Boltwood (1844-1872) and Margaret Mathilda Van Hoesen (1842-1909), and the grandson of Lucius Boltwood (1792-1872) and Fanny Haskins Shepard (d. 1888).

Boltwood attended Albany Academy, Albany, New York, before entering Sheffield Scientific School of Yale University in 1889. He graduated from Sheffield in 1892 with the highest rank in chemistry. From 1892 to 1894 Boltwood studied rare earths and analytical methods in Germany. Boltwood returned to Yale as an assistant in chemistry in 1894 and was made an instructor of chemistry in 1896. He received his Ph.D. degree in chemistry from Yale in 1897. In 1900 Boltwood left Yale to open a private laboratory in New Haven which he operated with mining engineer Joseph Hyde Pratt until 1906. It was during this latter period that Boltwood began his career as a consulting chemist to manufacturers, miners, and prospectors.

Boltwood became interested in the field of radioactivity around the time Rutherford and Soddy announced their theory of disintegration of radioactive elements in 1900. Stimulated by the prospect of a visit by Rutherford to New Haven in 1904, Boltwood began experiments to prove that uranium and radium exist in a constant ratio in unaltered minerals. The results of the experiments gave strong support to the disintegration theory. Impressed with Boltwood's work, Rutherford urged him to continue working in the field. Rutherford's visit to Boltwood's laboratory in New Haven marked the beginning of a productive, friendly association between the two men. Boltwood's successive experiments in radioactivity led to the important discoveries and proofs referred to in the preceding pages.

Boltwood returned to Yale in 1906 as assistant professor of physics. During the academic year 1909-1910 Boltwood worked in Rutherford's laboratory at the University of Manchester. Upon his return from abroad, Boltwood was made professor of radiochemistry of Yale College, a position he held until his death in 1927. By this time, however, Boltwood's years of productivity in the field of radioactivity were largely over.

In the years following his return from England, Boltwood assisted Professor H. A. Bumstead in the building of the Sloane Physics Laboratory (1912) and became its acting director during Bumstead's absence in 1913-1914. Boltwood later devoted much of his time to planning the construction and equipment of the Sterling Chemical Laboratory (1921). This work seems to have put a tremendous strain on Boltwood's health and he suffered several nervous breakdowns before his eventual suicide in Maine on August 15, 1927.

Additional biographical material may be found in the Dictionary of American Biography, in A. S. Eve's biography, Rutherford, and in Rutherford and Boltwood, Letters on Radioactivity, edited by Lawrence Badash.

Guide to the Bertram Borden Boltwood Papers
Under Revision
Compiled by Linda Wrigley
November 1970
Description rules
Finding Aid Created In Accordance With Manuscripts And Archives Processing Manual
Language of description note
Finding aid written in English.

Part of the Manuscripts and Archives Repository

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