the same, Watt conceded that Cavendish’s interpretations were not identical to his own, and even admitted that ‘his is more likely to be [right], as he has made many more experiments, and, consequently has more facts to argue upon’. There is a trace of envy at Cavendish’s riches and status in comparison to Watt’s own humble origins (he was the son of a Clydeside shipbuilder) when he tells De Luc that he ‘could despise the united power of the illustrious house of Cavendish’. Yet Watt seems to have put aside his bitterness soon enough. He wrote a paper that same year describing his own experiments and ideas on water, in which he graciously noted that ‘I believe that Mr Cavendish was the first who discovered that the combination of dephlogisticated and inflammable air produced moisture on the sides of the glass in which they were fired.’ The unworldly Cavendish probably never knew about Watt’s initial anger; in 1785 he recommended Watt for a fellowship of the Royal Society.
This apparent conciliation did not prevent others from arguing over who discovered that water was a compound. Cavendish, Watt, Lavoisier and Monge have all been put forward as candidates. The debate raged heatedly in the mid-nineteenth century, when it centred on Watt’s rival claim. His case was argued forcefully by François Arago, secretary of the French Académie des Sciences, in his Eloge de James Watt, and Lord Brougham and Watt’s son James Watt Jr added their voices to this appeal. In response, William Vernon Harcourt, in his address as president-elect to the British Association for the Advancement of Science in Birmingham in August 1839, vehemently asserted Cavendish’s priority – a speech that left some members of the audience bristling, for Watt the engineer was a hero in the industrial Midlands of England.
David Philip Miller has shown that this ‘water controversy’ was fuelled by broader agendas. Watt Jr was no doubt motivated by filial concern for his father’s reputation, but Arago and Watt’s other supporters hoped that their protagonist’s claim to this discovery in fundamental science would lend weight to their belief in an intimate link between pure and applied science. Harcourt’s camp, meanwhile, consisted of an academic élite that was keen to promote the image of the ‘gentleman of science’ who sought knowledge for its own sake and remained aloof from the practical concerns of the engineer. The reclusive, high-born and disinterested Cavendish was its ideal exemplar. George Wilson’s biography of Cavendish was a product of this controversy – a polemic that aimed to establishing its subject’s priority and honourable conduct, it gave disproportionate attention to his experiments on water. But in other respects Wilson’s researches left him with a rather poor impression of Cavendish’s character, and his portrait set the template for the subsequent descriptions of a peculiar, asocial man, ‘the personification and embodiment of a cold, unimpassioned intellectuality’ as the editor of a collection of Cavendish’s papers put it.
There is, however, a postscript to Cavendish’s compulsive attention to detail that illustrates just how valuable to science pedantry can be. In 1783 he looked at the other component of common air, the ‘phlogisticated air’ that would not support combustion. This is, of course, nitrogen, which, as Cavendish showed, is converted into nitrous acid via reactions with oxygen. ‘Acid in aerial form’ was how Blagden summarized Cavendish’s conclusions about phlogisticated air, and both he and Priestley felt that these studies represented a more important contribution than Cavendish’s work on water – a reflection of the ‘pneumatic’ preoccupation of chemists at that time.
But while Cavendish was able to eliminate nearly all of the phlogisticated component of common air, he remarked that there always seemed to be a tiny bit of ‘air’ left, which appeared as a recalcitrant bubble in his experiments. This seemed to make up just
Some years later, an English chemistry student named William Ramsay bought a second-hand copy of Wilson’s book and read about the mysterious bubble. That reference lodged in his remarkable mind, and he recalled it in the 1890s when he was a professor of chemistry at University College, London. Ramsay was at that time corresponding with the English physicist Lord Rayleigh, who suspected that nitrogen extracted from air might have a small impurity of some unreactive substance. They repeated Cavendish’s experiments on nitrogen, and in 1894 they announced that they had discovered a new element, one that did not seem to react with any other. They named it after the Greek world for ‘idle’: argon. Within several years, Ramsay had found three other, similarly inert, gases and had unearthed an entirely new group of the periodic table of elements. That was the start of another story, and in Chapter 8 we shall hear its conclusion.
* That was why wood got lighter as it was consumed by flames. But, inconveniently, metals got heavier when they were heated (calcined) in air, even though they were supposed to be losing phlogiston. No problem, said the advocates of phlogiston theory: apparently this volatile ‘principle of combustion’ can sometimes have negative weight.
CHAPTER 3
New Light
The Curies’ Radium and the Beauty of Patience
Paris, 1898–1902—In a cold and damp wooden shed at the School of Chemistry and Physics, the Polish scientist Marie Curie, occasionally assisted by her French husband Pierre, crushes and grinds and cooks literally tons of processed pitchblende, the dirty brown material left over from the mining of uranium. The Curies are convinced that this unpromising substance contains two new elements, which they name polonium and radium. After endless chemical extractions, Marie obtains solutions that glow with pale blue-green light: a sign that they contain the intensely radioactive element radium. The significance of the work is recognized straight away, as Marie and Pierre, still struggling to forge scientific careers in France, are awarded the Nobel prize in physics in 1903.
Marie Curie may well have felt ambivalent about becoming an icon for women’s place in science. Like several trail-blazing women scientists, she seemed eager that her sex be seen as irrelevant. Sadly, it was not. Those scientists, such as Albert Einstein and Ernest Rutherford, who accepted Marie without question as an equal, stand out for their lack of prejudice; most of the scientific community at the end of the nineteenth century was reluctant to believe that a woman could contribute new, bold and original ideas to science. When Marie was grudgingly awarded prizes for her groundbreaking studies of radioactivity, as likely as not the news would be communicated via her husband. It was only by a hair’s breadth that she was included in the decision of the 1903 Nobel committee. And when the Paris newspapers discovered that, several years after Pierre’s death, Marie had had an affair with one of his former colleagues, they bit on the scandal with relish, when similar behaviour from an eminent male scientist would probably have been deemed too trivial to mention.
It is hardly surprising, then, that Marie took great pride in her work, carefully emphasizing her own contributions and hastening to publish them in the face of Pierre’s habitual indifference to public acclaim. Marie knew that, to make her mark, she would have to achieve twice as much as her male colleagues. And she did – which is why she became the only scientist to win two Nobel prizes in science.
Her life has been so often romanticised – that process began as soon as the news came from Stockholm in 1903 – that Marie Curie herself has tended to disappear behind the stereotype of the tragic heroine. Yet it is true that her life was marred by several tragedies and by considerable adversity, and it is not surprising that in the end this left her hardened, appearing aloof and cold to those around her. Her determination and dedication to her work could translate as a certain prickliness and unfriendliness towards her colleagues. If she expected others to ignore the fact that she was a woman, likewise she herself had no concern about protecting brittle
