Women in Their Element

The following sections are included:

• Contents
• Foreword from the President of the European Chemical Society
• Foreword from the Co-chair of the IYPT Management Committee
• Preface and Acknowledgements

The periodic system of chemical elements is one of the best-known and most used icons of modern science. It appears everywhere: on the internet, on sweaters and mugs, in textbooks — and in lecture halls all over the world. Although not everybody is familiar with the periodic system and understands what it represents, most will have an idea of it as an important symbol for and tool in the science of chemistry. Many may have heard of its most celebrated creator, the Russian chemist Dmitri Ivanovich Mendeleev (1834–1907), who came up with the idea of a classification when working on a chemistry textbook for his students at St. Petersburg University. The first published form of his periodic table, which Mendeleev presented as a system from the start, was dated 17 February 1869 (Gregorian calender), and appeared in 150 Russian and 50 French copies [Gordin, 2004, p. 29]. To celebrate the 150th anniversary of the discovery of this periodic system, the United Nations’ General Assembly has declared 2019 the International Year of the Periodic Table of Chemical Elements (IYPT). On the website for this International Year, the periodic system is celebrated as “one of the most significant achievements in science, capturing the essence not only of chemistry, but also of physics and biology” [IYPT, 2019]. The historian Michael D. Gordin, Mendeleev’s biographer, has even described it as “the single most important discovery of inorganic chemistry in the nineteenth century — and quite possibly of chemistry in general, in any century” [Gordin, 2015, p. 53]…

Although cobalt compounds had already been in use for colouring glass and ceramics for centuries, the Swedish chemist Georg Brandt (1694–1768) is usually credited with discovering the element in 1735 [Weeks, 1960]. In the Acta literaria et scientiarum Sveciae of that year, Brandt published a detailed account in which he showed that cobalt was clearly distinct from bismuth after he had produced both metals from the same ore [Brandt, 1735]. But cobalt compounds were commercial products and objects of research long before Brandt’s important publication. In 1705 and 1706 Dorothea Juliana Wallich published three chymical books under the pseudonym D.I.W. [Wallich, 1705a, 1705b, 1706]. These books were the result of her work with a cobalt-containing ore, and focussed on producing the philosophers’ stone which was supposed to transmute metals such as lead and tin into silver and gold. Wallich also recorded some chymical experiments with cobalt compounds. By discovering the thermochromic reactions of certain cobalt compounds she contributed to the early understanding of the properties and behaviour of the element cobalt.

In April 1738, about fifty years before Antoine-Laurent Lavoisier (1743–1794) reformed chemistry in France, the Académie des sciences de Paris (French Academy of Sciences) announced the winners of a competition devoted to the question of the nature and the propagation of fire. The Greeks considered fire, along with air, water and earth, to be an element. As further knowledge of matter was gained through its transformations such as metallurgy, another series of elements or principles introduced by the Arabs — sulphur, mercury and salt — were preferred, as they allowed for a better understanding of actual laboratory practice and were widely used in alchemy. The two systems did not exclude each other, and to chymists, fire remained to be a mysterious phenomenon that was to be investigated…

Antoine-Laurent Lavoisier (1743–1794) is often referred to as the “father of the Chemical Revolution,” which included the radical notion of a chemical element as simple substance and a new theory of combustion. Above all, Lavoisier was the individual who named oxygen and demonstrated the crucial role of that element in calcination (heating to high temperatures in air) and all kinds of combustion, including respiration [Bret, 2018]…

The following sections are included:

• A Literary Lady
• Conversing About Chemistry
• References
• Select Bibliography

The six platinum-group metals are ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt). They have fairly similar physical and chemical properties. They occur together in the same mineral deposits. So it is difficult to separate them from each other chemically. Separating them was necessary in order to determine their atomic weights and to find their place in the periodic table, which initially was ordered by increasing atomic weight [Griffith, 2008]. In 1871, a woman named Julia Vsevolodovna Lermontova worked on the separation process of the platinum group, a topic which had been discussed in the chemical community for a long time…

Because of the perceived need for chemistry in the mining industry, chemical analysis has always been a prominent part of chemistry in Sweden [Lundgren, 2008]. A good chemist was a good analyst — and a good analyst was a prerequisite for discovering and investigating new elements. In Sweden analysis remained to be the dominant way of discovering elements during the nineteenth century. The discovery of erbium, terbium, vanadium, thulium, holmium and a host of other elements happened in this country, and all these found their way into the periodic table, as well as some others — norium, wasium, etc. — which were later shown to be nonexistent. This essay will reflect on the role of women chemists in analytical chemistry with examples from Sweden. I will do so with the help of the common metaphor that equates laboratory work with work in the kitchen. This metaphor is appropriate, not only because many chemists often jokingly refer to their chemistry in cookery terms, but more importantly because chemistry was, up to the end of the nineteenth century, often carried out in homes, in physical proximity to the kitchen, and sometimes in it. There existed hardly any boundary between household, kitchen and laboratory. Jöns Jacob Berzelius’ (1879–1848) laboratory was an integrated part of his household and adjacent to kitchen and bedroom [Söderbaum, 1929, p. 310]. Equipment for chemical experiments was often the same as that used in kitchens, as were techniques necessary for analysis, such as grinding with mortar and pestle, decanting, boiling, etc. Kitchen ovens were regularly used for sand baths. Wives, daughters, housemaids and other members of the household therefore naturally contributed to the work, and often acted as laboratory assistants. Antoine Lavoisier’s wife Marie-Anne Paulze (1758–1836) was not unique in this regard. Two examples from Sweden are Sara Pohl (1751–1793), Carl Wilhelm Scheele’s housekeeper, and Anna Sundström (1785–1871) [Trofast, 2018] Berzelius’ housekeeper — known among his pupils as “die strenge Anna” (“the strict Anna”), who, as Berzelius stated, “took care of my person and of my laboratory glasses” [quoted in Trofast, 1979, p. 54], and as Berzelius’ friend Carl Palmstedt (1785–1870) wrote to him in 1818, she knew “where everything stands and perhaps knows that better than you [Berzelius]” [Trofast, 1979, p. 63]. She took active part in moving laboratory utensils to Berzelius’ new home in 1818 [Söderbaum, 1929, p. 185; Trofast, 1979, pp. 79, 90, 93–95,148]. Palmstedt wrote to Berzelius in 1819 that she “lives in the laboratory, where she arranged all glass vessels in neat groups, so that nothing broke” [Trofast, 1979, p.114] (Figure 1).

In the course of her lifetime the Swedish scientist Astrid Cleve (1875–1968) was active in a number of different fields of research (Figure 1). Her initial interest was in botany, the subject in which she earned her doctorate at Uppsala University in 1898. In doing so, she became the first woman in Sweden with a PhD in science. Another early interest was the analysis and systematisation of diatoms. This was a life-long pursuit, crowned with the monograph Die Diatomeen von Schweden und Finnland (“The Diatoms of Sweden and Finland”), for which she was awarded the honorary title of professor by the Swedish government in 1955. After World War I she mainly conducted research in geology and archaeology, as well as, to some extent, theology…

During the past century Ellen Henrietta Swallow Richards (1842–1911) has been recognised as the founder or a pioneer in such diverse fields as home economics, ecology, sanitary engineering, public health, nutrition, and women’s education [Hunt, 1912; Clarke, 1973; Musil, 2014; Swallow, 2014]. As a teacher and chemist, she adeptly applied the principles and techniques of her scientific training in all her work throughout her long career at the Massachusetts Institute of Technology (MIT). Less well known is that she was also considered “an eminent mineralogist in her day” [Schneiderman, 2018, p. 4] and was highly regarded for her careful and accurate chemical analyses of minerals, as well as of water samples, at a time when most women were not yet allowed in college classrooms.

Fluorine is a very pale yellow-green gas, the lightest halogen element, with atomic number 9. It is the most electronegative element of all, reacting with almost all other elements, including some noble gases. It was not isolated until late nineteenth century, though its compounds have been known for several centuries…

In 1912 the English chemist John Albert Newton Friend (1881–1966) conceived a multi-volume Textbook of Inorganic Chemistry, and to assist in its production he recruited writers — thirteen men and four women — from colleges, universities and industry, mainly in Birmingham and Leeds. Running to twenty-one volumes, the Textbook was published over the period 1914 to 1937. The physicist Dr William Garnett (1850–1932) wrote in the publisher’s centenary volume that “it must have required some courage to have embarked upon the venture of publishing” the Textbook but he felt that it was of high quality, in particular because of the association of some writers with industry [Garnet, 1920, p. 92]. Some of the writers who prepared volumes for Friend were, indeed, employed in industry, while others came from technical colleges or universities in the industrial north of England, where an association with industry was more common than in universities like Oxford and Cambridge. In their coverage of the elements and their compounds, there is frequent reference to industrial production and uses, in addition to the generally more scholarly coverage of physical and chemical properties…

When in April 1901 the German Association for Electrochemistry convened in Freiburg for its annual meeting, there was, for the first time, a woman among the participants. This was Clara Immerwahr from Breslau, who had completed her PhD just a few months earlier. Immerwahr thus ranks among a small, yet significant group of women scientists who entered the exclusively male domain of scientific research at the turn of the twentieth century. Clara’s research on the electrochemical properties of cadmium, copper, lead, mercury, and zinc in equilibrium with their salts in solution broadened the empirical basis for the notion of “electroaffinity,” as coined by her PhD adviser, Richard Abegg (1869–1910). Electroaffinity (electronegativity in modern nomenclature) varies characteristically along the rows and columns of the periodic system, and complements the organizing principle encapsulated in it.

Today we take for granted that we know that stars like our Sun are made up primarily of hydrogen (73%) and helium (25%), and are powered by nuclear fusion. Fewer than 100 years ago, however, this was such an unlikely truth that even the discoverer doubted her own findings. Atomic fusion was not discovered until the 1930s, and scientists believed that the Sun had a similar elemental composition to that of the Earth. So when the British-born astrophysicist, Cecilia Payne-Gaposchkin (1900–1979) reported the results of her spectral analysis of the solar atmosphere in her PhD dissertation, suggesting that hydrogen and helium atoms far outnumbered any other elements, even she was reluctant to believe her own findings. Today, we recognise Payne-Gaposhkin as the first astronomer to propose this correct composition. Although her own career reflected the limitations placed on women in science in the early twentieth century, her persistence in pursuing her scientific work helped to open up opportunities for women at universities and observatories. She became, as she described it, “a thin wedge” in making space for women in astronomy [Kidwell 1996, p. 28]…

On 5 September 1925, a young woman finished her presentation on the newly discovered eka-manganese elements at the annual general assembly of the “Verein Deutscher Chemiker” (“Association of German Chemists”) in Nuremberg. After she had finished, the chair of the chemical society, Professor Friedrich Quincke (1865–1934), referred to this talk as a historic moment — not because of the discovery of the new elements, which had been named “masurium” and “rhenium,” but rather because, for the first time, a “Kollegin” (a female colleague) had addressed the Association. He finished by expressing the hope that this example would be followed by many other “Chemikerinnen” (female chemists) [Tacke, 1925a]. These hopes, like the acceptance of the new elements, would meet a somewhat different future. While rhenium was eventually accepted into the periodic system and figures in it to this day, element 43 is now known as “technetium,” and its discovery credited to Carlo Perrier (1886–1948) and Emilio Gino Segrè (1905–1989). A year after the meeting the young woman, Ida Tacke (1896–1978), married Walter Noddack (1893–1960), with whom she had been searching for the eka-manganese elements for several years, which made it difficult for her to pursue a career in her own right. Most of her female contemporaries experienced the same fate, especially as Nazism increasingly branded women as wives and mothers, not as professionals, including scientists, except if in support of their husbands’ careers. Noddack continued her life as a wife and scientist, mostly because she was the wife of a scientist, and this granted her access to a laboratory and the necessary literature. Her expertise in the chemical properties of missing elements lead to her 1934 proposal of the possibility of what would later be called “nuclear fission,” at a time when the “radioactivists” were unable to imagine this process.

Erika Cremer (1900–1996) was a German (later Austrian) physical chemist who is today best known for her pioneering but belatedly recognised work with her students in developing the technique of gas-solid chromatography, beginning in 1944 [Ettre, 2008; Kolomnikov et al., 2018, pp. 112–113; Johnson, 2019]. But before taking up chromatography, Cremer had worked for more than a decade (1932–1943), under extremely difficult conditions, on the quantum chemistry of molecular hydrogen, which she first encountered while working at the Kaiser Wilhelm Institute for Physical Chemistry in Berlin. To understand the course of this investigation and the difficulties that Cremer had to deal with in conducting it, it is necessary to discuss Cremer’s work and the obstacles to her academic career in the political and social context of Weimar and National Socialist Germany from the 1920s to the 1940s…

Carbon is a chemical element with the symbol C and an atomic number of six. It is non-metallic and tetravalent since it has four electrons available to form covalent chemical bonds. The atoms of carbon can bond together in different ways, forming what are known as allotropes, such as diamond and graphite. The physical properties of carbon vary according to the allotropic form. For example, graphite is opaque, one of the softest materials known and is a good electrical conductor. Diamond is highly transparent, the hardest naturally occurring material known, and has a low electrical conductivity. Carbon forms long chains of interconnecting carbon–carbon bonds, a property referred to as catenation. The element occurs in all known organic life and is the basis of organic chemistry. Organic molecules can contain straight chains of carbon atoms, or the carbon atoms can be arranged in a ring as in benzene…

On 2 August 1938, the French journal Le Figaro reported that professor Jean Perrin (1870–1942) of the Sorbonne in Paris had announced the discovery of element 93 by a M. Hulube [sic] during a meeting of the Académie des Sciences (the French Academy of Sciences). The short note of just three sentences ends with a reference to the newly devised “spectrograph” that had delivered proof of the element’s existence — a spectrograph invented by “Melle Cauchois” [N. N., 1938]. This new spectrograph significantly extended the number of applications for the (by then well-established) method of X-ray spectrography, which had been used to distinguish and characterise elements since 1914. Thirteen months later, a publication by Horia Hulubei (1896–1972) and Yvette Cauchois (1908–1999) (Figure 1) in the Compte rendus de l’Académie des sciences claimed that the discovery of the “natural element 93” had been confirmed, and suggested that it should be named “sequanium,” from the Latin for the river Seine [Hulubei and Cauchois, 1939b, p. 479]. The use of the qualifier “natural” is to be understood as a contrast to other contemporary scientists’ efforts to produce unknown elements by bombarding nuclei of known elements with particles. That approach was chosen by the Italian physicist Enrico Fermi (1901–1954) in 1934, in his attempt to produce elements 93 and 94; however, he was later unable to provide any chemical evidence of their existence. The same fate was met by the “natural element 93,” whose claim of existence was later abandoned, and sequanium is now among the “lost” elements gathered in a recent study of the same title, The Lost Elements [Fontani et al., 2014, pp. 321–336]. But the new instrument used in its discovery, also known as the “Cauchois spectrograph,” justified its existence and utility quite independently, and continued to be used to improve the observation and the identification of elements, both known and unknown. With this, her invention, Yvette Cauchois contributed to the knowledge of the periodic system, and equipped the scientific community with another means to detect the elements, old and new, and even spot their inner structure.

No element is more closely related to a woman scientist than radium is to Marie Skłodowska Curie (1867–1934). The story of the discovery of polonium and radium has been told many times, not least by the Curie family itself. Precisely for this reason it needs to be retold, as important insights into exceptionality and entrepreneurship have recently challenged the heroic tale. The story of Marie Curie and radium is not just about personal resolution and physical force, but also about family cooperation, domestic decisions, and the public value of commercial science…

The end of the nineteenth and beginning of the twentieth centuries was a particularly exciting time for chemistry: many questions, few clear answers. One of the most perplexing questions was the nature of the substance released from radioactive heavy elements, such as radium. Was it a vapour? Was it a finely divided particulate? Was it a gas? This enigmatic substance was named “emanation” by Ernest Rutherford (1871–1937) to encompass all possibilities. The issue was settled by the bold title of a research article by Rutherford and his research student Harriet Brooks (1876–1933): “The New Gas from Radium” [Rutherford and Brooks, 1901]. We now call “the radioactive gas” the element radon, and this was the first ever mention of it.

New scientific concepts need a new name. The term “isotope” was coined to describe atoms of the same element with identical chemical properties but differing in atomic weight. The name was proposed in 1913 by Dr Margaret Georgina Todd (1859–1918) (Figure 1), and it was a brilliant choice, as its derivation from the Greek isos topos, meaning “same place,” reaffirmed the primacy of the periodic table at a time when the fundamental basis for the ordering of the elements was in question.

The discovery of chemical elements cannot be separated from the discovery of isotopes. And one of the most important contributions to the discovery of the existence of isotopes was made by a long-forgotten woman chemist, Stefanie Horovitz (1887–1942) (Figure 1). It was her incredibly precise and accurate gravimetric measurements which confirmed that lead from uranium-rich minerals had a definite different atomic weight (mass) to that of “ordinary” lead. Later, she and her supervisor, Otto Hönigschmid (1878–1945), disproved the existence of the claimed element ionium.

The years following the discovery of radioactivity were exciting times for chemists and physicists. Scientists sought to find out why certain substances emitted this newly discovered radiation, what characterized it, and what the relation between the radioactive substances was. In the decades leading up to the 1920s concepts and phenomena such as the theory of atomic disintegration (the transformation theory), isotopes, half-lives, and decay series displaying parenthood among the radioactive elements helped unveil the cloud of mystery that had surrounded the field of radioactivity from the very beginning…

Thorium, today a member of the actinide group of elements, was first identified by the Swede Jöns Jacob Berzelius (1779–1848) [1829], and within a few weeks of each other, first the German chemist Gerhard Carl Schmidt (1865–1949) [1898] and then Marie Curie (1867–1934) [1898] announced that it was radioactive. The major source of thorium is the mineral monazite, the major constituent of which is cerium phosphate, but other lanthanides and uranium are also present in low concentrations. The English chemist May Sybil Leslie (1887–1937) made several 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 products would later be identified as isotopes of both known and newly discovered elements, but at that time her research was part of exciting new developments in science that revolved around the phenomenon of radioactivity, and the nomenclature that was far from settled…

When the Austrian physicist Lise Meitner (1878–1968) (Figure 1) moved from Vienna to Berlin in 1907 to do research on radioactivity, the field was full of both promise and uncertainty. Not a decade had passed since the discovery of polonium and radium by Pierre and Marie Curie, and the complex relations between radioactive species were being investigated by the radioactivists, physicists and chemists with access to those rare, energy-emitting substances [Hughes, 1993]. More than twenty radioactive species had been described and grouped into three main series, named after the longest-lived precursors, as in the uranium and thorium series, or the species’ presumed parent element, as in the actinium series. Elements in each series decayed into one another emitting alpha (α-) and beta (β-)radiations, whose nature was not yet entirely clear…

“She is in the next room!” This is how one of Elizabeth Róna’s colleagues responded to a biologist of the Medical Division of the Argonne National Laboratory who, in need of a polonium source, was trying to locate Róna in Europe in 1947. An amount of polonium as small as the head of a pin was radioactive enough to be used as an alpha (α-)particle source in biological experiments of single cells. At the time, Elizabeth Róna (1890–1991), a Hungarian radiochemist, known also as the “polonium woman,” was the leading expert in preparing polonium sources. She had been trained by Irène Curie (1897–1956) at the Radium Institute in Paris; she worked for 13 years at the Institute for Radium Research in Vienna preparing polonium for medical and laboratory use; and she got involved in one of the most important scientific controversies of the interwar period over the artificial disintegration of light elements as part of the Viennese group…

For decades, chemists had been searching for the missing heaviest alkali metal. It was to be the French scientist, Marguerite Perey (1909–1975) (Figure 1) who conclusively identified this elusive short-lived radioactive element and named it after her country: francium. The discovery was to bring fame to this researcher at the Institut du Radium (the Radium Institute), a centre for radioactivity studies founded by Marie Curie (1867–1934).

During World War II the Austrian physicist Berta Karlik (1904–1990), together with her assistant Traude Bernert (1915–1998), discovered isotopes 215, 216, and 218 of element 85, “eka-iodine.” Element 85 is known today as astatine. It is part of two of the natural decay chains, namely the uranium or radium series, and the actinium series. Astatine is very rare in nature, and therefore several erroneous discoveries were made. Astatine naturally appears for just a short time during the decay of radium, thorium and actinium. However, in 1940 Emilio Segré (1905–1989) and his team at the University of California in Berkeley managed to produce the isotope astatine-211 artificially by bombarding bismuth-209 with alpha (α-)particles. This was 3 years before Karlik and Bernert were finally able to detect it in the natural decay chains.

14 November 1935. A postman rings the doorbell of the Curie laboratory in the Institut du Radium (the Radium Institute), and delivers a telegram to the French scientist Irène Joliot-Curie (1897–1956) (Figure 1). She reads aloud to her husband and colleague Frédéric Joliot-Curie (1900–1958), the recipient of the telegram…

Isabella L. Karle (1921–2017) (Figure 1) has been described as “the most distinguished female chemist” to be employed at the Manhattan Project’s Metallurgical Laboratory (Met Lab) [Howes and Herzenberg, 1999, p. 74]. She spent six months there, working on the chemistry of plutonium. This period is generally overlooked in sketches of her career, the majority of which was spent at the United States Naval Research Laboratory. Karle was a well-known and highly regarded crystallographer. She developed the symbolic addition procedure that demonstrated the usefulness of the mathematical technique for determining the structure of crystals, known as direct method. The direct method was pioneered by her husband, the chemist Jerome Karle (1918–2013) (Figure 1), and the mathematician Herbert A. Hauptman (1917–2011), who won the Nobel Prize in Chemistry in 1985.

Chien-Shiung Wu (1912–1997) (Figure 1) is often called “the Chinese Marie Curie” and “the First Lady of Physics” [Chiang, 2014, p. ix]. She was an expert in beta (β-)decay, a process in which a neutron within an atomic nucleus is transformed into a proton or vice versa by the emission of an electron or a positron, respectively. Wu is widely known for the experimental work she conducted that validated the theory of parity violation proposed by her colleagues Tsung-Dao Lee (b. 1926) and Chen-Ning Yang (b. 1922), both of whom won the Nobel Prize in Physics in 1957. Less well-known is her doctoral research on the fission products of uranium. In the course of this research, she identified two radioactive isotopes of the element xenon and established their decay chains. Knowledge of one of these isotopes was crucial to the operation of the nuclear reactors set up in Hanford, Washington, as part of the Manhattan Project…

After the discovery of the last naturally occurring element, francium, in 1939 [Perey, 1939], the pursuit to complete the periodic table became increasingly competitive, experimentally challenging and political. So far, there seems to be no limit on what scientists can create; as long as they can work out the recipe and accelerate beams to high enough energies, they will continue to push the limits of the periodic table. Long gone are the days of the seemingly primitive setup managed by the Curies, who discovered polonium and radium by extracting it from the uranium ore pitchblende [Curie et al., 1898]. For elements beyond uranium, i.e. with more than 92 protons (“transuranic elements”), and even heavier ones (“superheavy elements”), more advanced characterisation techniques are required. Superheavy elements (ca. 100 protons and beyond) have incredibly short lifetimes (microseconds), are extraordinarily difficult to create and have never been detected out of the few laboratories who work on them. Not only are the elements fascinating, but so too are the scientists who discovered them. Their names may not be as familiar as Marie Skłodowska Curie’s, but women have played leading roles in every aspect of superheavy discovery; challenging the biases of outdated laboratory members and transforming our understanding of the periodic table…

Sonja Smith-Meyer Hoel (1920–2004) was among Norway’s most influential female engineers of her time. She graduated as a chemical engineer at the Norwegian Institute of Technology in 1947, and worked her whole life in chemical industry, at Elkem, one of the twentieth century’s most important Norwegian companies. Hoel acquired knowledge and skills related to the production and properties of metals and alloys such as ferrosilicon, steel and aluminium, as well as to mineral wool. For many years, she was the director of the company’s patent office, and she was member of several committees and boards on patents in Norway as well as internationally…

Humans have learned a lot about the history of the Earth and other planets from the study of stable isotopes in nature. This isotope geochemistry emerged mainly in the years after World War II, as chemists and geologists began using physical instruments like mass spectrometers to analyse soil, rocks, and meteorites. Toshiko “Tosh” Mayeda (1923–2004) (Figure 1), a Japanese-American woman interned by her own government during the war, was one of the most talented and experienced mass spectrometer operators during this period, and helped to establish methods of using the isotopes of oxygen to study historic ocean temperatures and the history of the solar system. Although she never rose above the rank of laboratory assistant, she collaborated with two very influential chemists who became known as the founders of the new discipline. Moreover, her position allowed her effectively to run the laboratory in which she worked…

Mary Almond’s (b. 1928) work with iron occurred in the period 1951–1954, at the University of Manchester and Imperial College, London. It was the iron in rocks that concerned her — specifically iron minerals in sedimentary rocks that had aligned themselves with the Earth’s magnetic field at the time they were formed, hundreds of millions of years ago. Working as part of a small team assembled by physicist Patrick Blackett (1897–1974), Almond used an instrument called an astatic magnetometer to measure the direction and dip of iron minerals in samples of sandstones collected from nine sites across Britain. The aim was to test the theory of continental drift, which was far from accepted in the early 1950s. If these rock samples contained iron minerals that pointed in directions other than the current poles, and dipped at an angle consistent with formation in latitudes other than 60-ish degrees north, this would suggest that they had been formed in a “Britain” at a different place on Earth. Almond took the majority of the measurements and discovered that Britain did seem to have, in her characteristically understated words, “moved a bit” [Merchant, 2011, Track 1, [1:22:13–1:23:00]]…

Barbara Bowen’s (b. 1932) work with atmospheric ozone (O₃), an “allotrope” of oxygen consisting of three oxygen atoms, occurred in the period 1976–1980 at the headquarters of the British Antarctic Survey (BAS) in Cambridge, England. Here she was responsible for digitising the geophysical and atmospheric data collected at the two British bases in Antarctica, including measurements of total atmospheric ozone recorded by instruments called Dobson spectrophotometers. BAS had been recording the amount of ozone in the Antarctic atmosphere — along with many other variables — since 1956, because the ozone layer, about 50 km above sea level, was of interest to scientists concerned with improving understanding of the circulation of the atmosphere [Sullivan, 1961, pp. 239– 241; Dobson, 1968, pp. 399–401]…

In the early 1960s, the Reverend Martin Luther King, Jr. (1929–1968) spoke out for civil rights, and President John F. Kennedy (1917–1963) committed Americans to landing on the moon. Both inspired Reatha Clark King (b. 1938), the first African American woman scientist to work at the National Bureau of Standards in Washington, DC. Between 1963 and 1968, King tested chemical compounds being proposed for use in rocket propellants. The most dangerous were gaseous fluorine compounds, among them oxygen difluoride and chlorine trifluoride. They were toxic, corrosive, and exploded on contact with other substances, including those that were generally unreactive like steel and glass. To ensure that NASA had reliable data, King needed to design flame calorimetry equipment capable of controlling and measuring the activity of fluorine and other dangerous gases.

The periodic system of elements formulated by Dmitri Mendeleev (1834–1907) is widely recognized within the public sphere today largely thanks to the impact of innovative school teaching. One of the most durable object lessons has been the didactic use of cupcakes to depict the elements, a method invented in 1908 by Ida Freund (1863–1914), the first woman to be appointed to a university lectureship in chemistry in the United Kingdom. Cupcakes notwithstanding, Freund made a significant impact in chemical education, and she ardently fought for women’s professional status in chemistry on par with men’s. During her career, she advanced the collegiate science education of women in the UK at a time when women’s educational opportunities in science were relatively limited. Beyond her lifetime, Freund’s books remained influential for many decades, for their value both in teaching and in promoting the history of chemistry. Her excellent exposition of Mendeleev’s achievement reached wide audiences as a result of the popularity of her writing…

In 1908, when Alice Hamilton (1869–1970) (Figure 1) wrote her first article on industrial poisons, industrial medicine was largely non-existent in the United States — along with safety standards, labour laws, social insurance and workers’ compensation. Lead and other suspected toxic substances were widely used in American industry, and their potential dangers were widely ignored. The accepted American narrative was that American industry was progressive: that American factories were larger, better and more productive; and that American workers were healthier, better paid and better fed than those in other countries. Hamilton questioned such beliefs and empirically tested them. Her work led to widespread change in the United States.

The element lead with the symbol Pb (from Latin “plumbum”), with a relative atomic mass of 207,2 is counted among the heavy metals. Lead’s atomic number is 82, and it can be found in Group 14 and the sixth period of the periodic system. Three stable isotopes exist: ²⁰⁶Pb, ²⁰⁷Pb and ²⁰⁸Pb. Compared with other metals lead has a low melting point (327,43°C). This blue-white metal can be deformed easily. In nature it can be found as lead compounds and in ores [Hollemann, 2007, pp. 1002–1041]…

The following sections are included:

• Authors’ Biographies
• Elements Index
• Name Index
• General Index