Beschreibung
First edition of Watt's determination of the compound structure of water, which overturned millenia of dogma. Aristotle (384-322BC), borrowing the idea from Emperidocles (440BC), taught that everything was constituted from the four elements Earth, Fire, Air and Water. "James Watt (1736-1819) is usually acknowledged as the first one to consider water as a compound" (Aparicio & Elizalde, p. 1765). Watt is, of course, famous for his invention (or, rather, improvement) of the steam engine, which arguably ushered in the technological age, and it was undoubtedly his interest in steam which led to his investigations into the nature of water. "Watt's career as a scientist centered on his interest in chemistry. He performed numerous experiments, was in contact with several of the foremost chemists of the day (including Black, Priestley, and Berthollet), and occasionally ventured into the realm of theory" (DSB). "The most famous outcome of Watt's chemical work was his only publication to achieve a high profile in the scientific world of the time, 'Thoughts on the Constituent Parts of Water and of Dephlogisticated Air" . . . This became the basis for Watt's claim, against those of the eccentric aristocrat Henry Cavendish and Antoine Lavoisier, to be the discoverer of the compound nature of water . . . Watt also published a second, short paper immediately following the first one in the Philosophical Transactions, which essentially provided advice to anyone seeking to repeat his experiments, pointing to their delicacy and the various causes of variation in the results he had observed" (Miller, p. 138). The question of who first discovered the compound nature of water was controversial in the 1780s, and still is. In 1781 Cavendish carried out experiments on the electrical detonation of inflammable and dephlogisticated airs, determining that the resulting dew was pure water. He informed Joseph Priestley, who repeated the experiments and reported them to Watt. On the strength of Priestley's work, Watt then wrote to Joseph Black and Jean André de Luc (1727-1817) in April 1783, suggesting that 'Water is composed of dephlogisticated and inflammable air, or phlogiston, deprived of part of their latent heat.' Cavendish reacted to these developments by having his paper 'Experiments on air' read to the Royal Society on 15 January 1784. When De Luc obtained a copy of Cavendish's paper, he told Watt that Cavendish had published his ideas word for word, and urged him to submit a letter of his own to the Royal Society to establish his claim. Watt's paper was eventually read to the Society over more than one meeting in late April and early May 1784. "In the Philosophical Transactions paper of 1784, Watt most famously offered an interpretation of experiments in which dephlogisticated air and inflammable air were sparked together. He described what he saw: The first effect was the appearance of red heat or inflammation of the airs, which was soon followed by the glass vessel becoming hot . . . and as the glass grew cool, a mist or visible vapour appeared in it, which was condensed on the glass in the form of moisture or dew. He found that this moisture was water, the weight of which was equal to that of the airs that had been sparked together" (Miller, p. 135). This failed to solve the priority issue for Watt, however, as his paper missed the deadline for publication in the first half-volume for 1784, in which Cavendish's paper appeared, thus giving the impression that Cavendish's discovery was prior to Watt's. Aparicio & Elizalde, From Water to H2O: Using the Human Dimension of Science To Teach the Nature of Science, Journal of Chemical Education 95 (2018), 1763-70. Miller, The Life and Legend of James Watt, 2019. 4to, pp. 329-357. Disbound. Bestandsnummer des Verkäufers ABE-1695387113954
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