# May Sybil Leslie

May Sybil Leslie (14 August 1887 – 3 July 1937) was an English chemist who worked with Marie Curie and Ernest Rutherford. From 1920 until her death Leslie was a Fellow of the Royal Society of Chemistry.

## Biography

Leslie was born to Frederick Leslie, a coal miner and bookseller, and Elizabeth Dickinson. She was educated in Woodlesford and Leeds, graduating from a high school in 1905. She received her BSc in chemistry with first-class honors from the University of Leeds in 1908. The following year, she was awarded an M.Sc. for research with H.M.Dawson on the kinetics of the iodination of acetone. This research was then published in 1909 in the Transactions of the Chemistry Society. In that same year, she worked as a research assistant to Marie Curie in Paris at the Curie Institute (1909–1911) and wrote several articles in French on extraction of new elements from thorium and their properties. She had many contributions on the "emanation of radioactive thorium", and her minute measurement practices allowed her to provide robust data on the half-life, atomic weight and activity of the products of the disintegration series of thorium ("the thorium series") and actinium ("the actinium series"). These contributions were the latest in the developing field of radioactivity. Upon recommendation from Curie, she then moved to Manchester to work on the properties of thorium and actinium which "showed that products from different decay series were probably radon" with Ernest Rutherford at the Physical Laboratory of the Victoria University, Manchester. (1911–1912). After leaving Manchester she worked as a high school teacher in West Hartlepool (1912–1913) and as an assistant lecturer and demonstrator in chemistry at the University College in Bangor, Wales (1914–1915).
During World War I Leslie was hired in 1915 by the government to work as a chemist on explosive production, concentrating on nitric acid, for WWI efforts. She was promoted to be in charge of a government lab in Liverpool after optimizing the manufacturing of nitric acid which was instrumental in the production of large scale manufacturing of explosives. Women were held in low esteem in science and engineering in those years consequently making her the first woman to receive recognition for her war work and gaining her the promotion. Thus both her Bangor and Liverpool appointments were unusual and could be explained by the shortage of men during the war. She had lost her job in explosives research in 1917 upon return of male engineers from the front.
In 1918 Leslie was awarded a doctoral degree by the University of Leeds for her combined work on thorium and explosives, making her the first woman to be awarded with a doctorate degree from the University of Leeds. The same year she became a demonstrator in chemistry at Leeds and in 1928 a full lecturer in physical chemistry. During those years her research mostly focused on the chemistry of synthetic dyes. Back in 1920 she became Fellow of the Royal Society of Chemistry.
In 1923 Leslie married Alfred Hamilton Burr, a chemist at Salford. In 1929 she left Leeds to stay with her husband and returned to Leeds only after his death in 1933. She died four years later on 3 July 1937.

## Main publications

* Leslie, M. S. (1911). "Le thorium et ses produits de désagrégation". Le Radium. 8 (10): 356–363. doi:10.1051/radium:01911008010035601.
* Leslie, M. S. (1912). "Sur la période du radiothorium et le nombre des particules α données par le thorium et ses produits". Le Radium. 9 (8): 276–277. doi:10.1051/radium:0191200908027601.
* Leslie, M. S. (1912). "LXI.A comparison of the coefficients of diffusion of thorium and actinium emanations, with a note on their periods of transformation". Philosophical Magazine. Series 6. 24 (142): 637–647. doi:10.1080/14786441008637369.
* Mrs. May Sybil Leslie Burr (1925). The Alkaline Earth Metals. Griffin.
* John Newton Friend; Joshua Craven Gregory; May Sybil (Leslie) Burr (1926). Beryllium and its congeners. Griffin.