The Discovery of the Periodic Table - the Chemical Revolution from Lavoisier to Mendeleev

This paper was written to investigate the order of discoveries made in chemistry leading up to the discovery of the periodic table. New experimental techniques, such as the pneumatic trough, voltaic pile, spectroscopy, and potassium analysis led to the discovery of many new elements and their properties which enabled the discovery of the periodic table. The discoveries led to the demise of the classical theory of the elements, to the end of the phlogiston theory and to the creation of the modern ideas of the elements and of the atomic theory. The paper shows the discoveries were made in a necessary and inevitable order with new experimental techniques leading to the discovery of new elements which eventually led to the discovery of the periodic table.

The Ghost of Sendivogius

This chapter builds on Newton's increasing interest in sulfur, placing his theories in the context of developments within the chymical community of the late seventeenth and early eighteenth centuries. It provides a new look at Newton's developing ideas about affinity and his role in the eighteenth-century development of affinity tables, the graphic representations of selective attractions by materials that cause those with less affinity to precipitate. Newton's attribution of refractive power to the sulfur content of illuminated materials justifies the view that he held a chymical theory of light. Nor did this fact escape his successors. In the years directly before the Chemical Revolution of the late eighteenth century, European chymists tried to push Newton's chymistry of light further by attaching his linkage of refractivity and sulfur to the phlogiston theory championed by Georg Ernst Stahl.

Public and Private

This chapter shows that Newton developed a theory of refraction based on the chymical principle sulfur, which he described in the first edition Opticks (1704). It also finds that the seeds of this theory extend back to Newton's 1675 Hypothesis of Light, where he explicitly abandons the Sendivogian theory of an aerial niter that he had affirmed in Of Natures obvious laws. Newton replaced the aerial niter, which had accounted for phenomena ranging from combustion and respiration to the fertilization of the earth, with a growing reliance on sulfur. Although he had reasons of his own for making this shift, Newton was also influenced by parallel developments in European chymistry, a field that was rapidly moving toward what would eventually be known as phlogiston theory.

O episódio histórico das teorias do flogisto e calórico: criando interfaces entre a História e Filosofia da Ciência e o Ensino de Química na busca pela humanização do trabalho científico.c

ResumoA análise de episódios da história da ciência pode ser usada como uma estratégia didática que promove a superação de visões descontextualizadas da ciência. Permitindo que os alunos vivenciem a construção do conhecimento científico e percebam que eles não são feitos a partir de lampejos de genialidade ou de maneira isolada. Tornando-se impossível elencar apenas um indivíduo para representar a formulação de uma lei ou teoria. Neste trabalho nosso objetivo é apresentar a contribuição de Lavoisier no episódio histórico sobre o abandono da teoria do flogisto e ascensão da teoria do calórico, salientando a importância dada a experimentação no século XVII e XVIII e buscando com isto nos livrar de narrativas anedóticas, descontextualizadas e elitistas ainda presentes no Ensino de Química que colocam este personagem como pai da química moderna.Palavras-chave: História e Filosofia da Ciência; Ensino de Química; Lavoisier.AbstractThe analysis of episodes of the history of science can be used as a didactic strategy that promotes the overcoming of decontextualized visions of science. This makes the students experience the construction of scientific knowledge and realize that they are not made from glimpses of genius or in an isolated way, being impossible to list only an individual to represent the formulation of a law or theory. In this work, our objective is to present the real contribution of Lavoisier in the historical episode about the phlogiston theory abandonment and the rise of the caloric theory. From this, it is possible to stress the importance given to experimentation during the 17th and 18th century, seeking to get rid of anecdotal, decontextualized and elitist narratives that are still present in the Teaching of Chemistry that put this personage like father of the modern chemistry.Keywords: History and Philosophy of Science; Chemistry teaching; Lavoisier.

Eight sages over five centuries share oxygen's discovery

During the last century, historians have discovered that between the 13th and 18th centuries, at least six sages discovered that the air we breathe contains something that we need and use. Ibn al-Nafis (1213–1288) in Cairo and Michael Servetus (1511–1553) in France accurately described the pulmonary circulation and its effect on blood color. Michael Sendivogius (1566–1636) in Poland called a part of air “the food of life” and identified it as the gas made by heating saltpetre. John Mayow (1641–1679) in Oxford found that one-fifth of air was a special gas he called “spiritus nitro aereus.” Carl Wilhelm Scheele (1742–1786) in Uppsala generated a gas he named “fire air” by heating several metal calcs. He asked Lavoisier how it fit the phlogiston theory. Lavoisier never answered. In 1744, Joseph Priestley (1733–1804) in England discovered how to make part of air by heating red calc of mercury. He found it brightened a flame and supported life in a mouse in a sealed bottle. He called it “dephlogisticated air.” He published and personally told Lavoisier and other chemists about it. Lavoisier never thanked him. After 9 years of generating and studying its chemistry, he couldn't understand whether it was a new element. He still named it “principe oxigene.” He was still not able to disprove phlogiston. Henry Cavendish (1731–1810) made an inflammable gas in 1766. He and Priestley noted that its flame made a dew. Cavendish proved the dew was pure water and published this in 1778, but all scientists called it impossible to make water, an element. In 1783, on June 24th, Lavoisier was urged to try it, and, when water appeared, he realized that water was not an element but a compound of two gases, proving that oxygen was an element. He then demolished phlogiston and began the new chemistry revolution.

Carl Wilhelm Scheele, the discoverer of oxygen, and a very productive chemist

Carl Wilhelm Scheele (1742–1786) has an important place in the history of the discovery of respiratory gases because he was undoubtedly the first person to prepare oxygen and describe some of its properties. Despite this, his contributions have often been overshadowed by those of Joseph Priestley and Antoine Lavoisier, who also played critical roles in preparing the gas and understanding its nature. Sadly, Scheele was slow to publish his discovery and therefore Priestley is rightly recognized as the first person to report the preparation of oxygen. This being said, the thinking of both Scheele and Priestley was dominated by the phlogiston theory, and it was left to Lavoisier to elucidate the true nature of oxygen. In addition to his work on oxygen, Scheele was enormously productive in other areas of chemistry. Arguably he discovered seven new elements and many other compounds. However, he kept a low profile during his life as a pharmacist, and he did not have strong links with contemporary prestigious institutions such as the Royal Society in England or the French Académie des Sciences. He was elected to the Royal Swedish Academy of Science but only attended one meeting. Partly as a result, he remains a somewhat nebulous figure despite the critical contribution he made to the history of respiratory gases and his extensive researches in other areas of chemistry. His death at the age of 43 may have been hastened by his habit of tasting the chemicals that he worked on.

The collaboration of Antoine and Marie-Anne Lavoisier and the first measurements of human oxygen consumption

Antoine Lavoisier (1743–1794) was one of the most eminent scientists of the late 18th century. He is often referred to as the father of chemistry, in part because of his book Elementary Treatise on Chemistry. In addition he was a major figure in respiratory physiology, being the first person to recognize the true nature of oxygen, elucidating the similarities between respiration and combustion, and making the first measurements of human oxygen consumption under various conditions. Less well known are the contributions made by his wife, Marie-Anne Lavoisier. However, she was responsible for drawings of the experiments on oxygen consumption when the French revolution was imminent. These are of great interest because written descriptions are not available. Possible interpretations of the experiments are given here. In addition, her translations from English to French of papers by Priestley and others were critical in Lavoisier's demolition of the erroneous phlogiston theory. She also provided the engravings for her husband's textbook, thus documenting the extensive new equipment that he developed. In addition she undertook editorial work, for example in preparing his posthumous memoirs. The scientific collaboration of this husband-wife team is perhaps unique among the giants of respiratory physiology.