Ada Hitchins

Ada Florence Remfry Hitchins (26 June 1891 – 4 January 1972) was the principal research assistant of British chemist Frederick Soddy, who won the Nobel prize in 1921 for work on radioactive elements and the theory of isotopes.

[1][2][3] Hitchins isolated samples from uranium ores, taking precise and accurate measurements of atomic mass that provided the first experimental evidence for the existence of different isotopes.

[1] Her careful preparation of radioactive materials, and her painstaking experimental work with uranium, protactinium, and lead isotopes, made crucial contributions to the research for which Soddy received the Nobel Prize.

In 1907, the American radiochemist Bertram Boltwood had isolated what he believed to be a new intermediate element in the decay chain between uranium and radium, "ionium".

[9] Hitchins helped to determine the atomic weight of lead based on measurements of radioactive ores, work that was important in developing an understanding of isotopes.

The discovery of protactinium completed the early version of the periodic table proposed by Dmitri Mendeleev, who predicted the existence of an element between thorium and uranium in 1871.

With regard to the new work, in the absence of one of us on military service since 1915, the experiments were continued for a time by Miss Ada Hitchens, [sic] B.Sc, Carnegie Research Scholar, until she also left to engage in war duties.

[11]In her early work with Soddy, Hitchins helped to prepare radium standards for the calibration of gold-leaf electroscopes, used to measure radioactivity.

[1] After she returned to work with Soddy in 1921, Hitchins further refined measurements of the half-life of ionium, and determined ratios of thorium isotopes in mineral samples.

[1] Soddy wrote of her: I regard Miss Hitchins as an exceedingly accomplished chemist with a wide knowledge and experience of difficult chemical and mineral analysis.

[4] After her retirement, the department's annual report said of her that "she filled the post of Chemist and Assayer gaining an outstanding reputation for accuracy and complete reliability, and her loss was keenly felt by the mining industry.