"word was used universally by scientists as a replacement for ""airs"". Van Helmont (1579 – 1644) is sometimes considered the founder of pneumatic chemistry, as he was the first natural philosopher to take an interest in air as a reagent. Alessandro Volta began investigating pneumatic chemistry in 1776 and argued that there were different types of inflammable air based on experiments on marsh gases. Pneumatic chemists credited with discovering chemical elements include Joseph Priestley, Henry Cavendish, Joseph Black, Daniel Rutherford, and Carl Scheele. Other individuals who investigated gases during this period include Robert Boyle, Stephen Hales, William Brownrigg, Antoine Lavoisier,"
"closely with Charles Blagden, an association that helped Blagden enter fully into London's scientific society. In return, Blagden helped to keep the world at a distance from Cavendish. Cavendish published no books and few papers, but he achieved much. Several areas of research, including mechanics, optics, and magnetism, feature extensively in his manuscripts, but they scarcely feature in his published work. Cavendish is considered to be one of the so-called pneumatic chemists of the eighteenth and nineteenth centuries, along with, for example, Joseph Priestley, Joseph Black, and Daniel Rutherford. Cavendish found that a definite, peculiar, and highly inflammable gas, which"
"to 1/120 of the original volume of nitrogen. By careful measurements he was led to conclude that ""common air consists of one part of dephlogisticated air [oxygen], mixed with four of phlogisticated [nitrogen]"". In the 1890s (around 100 years later) two British physicists, William Ramsay and Lord Rayleigh, realised that their newly discovered inert gas, argon, was responsible for Cavendish's problematic residue; he had not made an error. What he had done was perform rigorous quantitative experiments, using standardised instruments and methods, aimed at reproducible results; taken the mean of the result of several experiments; and identified and allowed for"
"Cavendish in 1766. Alessandro Volta expanded the list with his discovery of methane in 1776. It had also been known for a long time that inflammable gases could be produced from most combustible materials, such as coal and wood, through the process of distillation. Stephen Hales, for example, had written about the phenomenon in the ""Vegetable Staticks"" in 1722. In the last two decades of the eighteenth century, as more gases were being discovered and the techniques and instruments of pneumatic chemistry became more sophisticated, a number of natural philosophers and engineers thought about using gases in medical and industrial"
"pneumatic trough, while integral throughout the eighteenth century, was modified several times to collect gases more efficiently or just to collect more gas. For example, Cavendish noted that the amount of fixed air that was given off by a reaction was not entirely present above the water; this meant that fixed water was absorbing some of this air, and could not be used quantitatively to collect that particular air. So, he replaced the water in the trough with mercury instead, in which most airs were not soluble. By doing so, he could not only collect all airs given off by"
"to Cavendish that water was a compound – instead he assumed that the airs contained a form of water, which phlogiston modified into liquid, elemental water. Phlogiston had given the Ancient Greek idea of water as an element a brief reprieve, but the Greek system was now under heavy scrutiny as the Royal Society commissioned its members to investigate the invisible airs. By the mid-1700s there were three known ‘airs’: It was this last air which caught the attention of Joseph Priestley, a Unitarian minister whose favourite pastime was the investigation of airs – specifically, fixed air, given off by"
"paper entitled ""Réflexions sur le phlogistique"" (Reflections on Phlogiston), a full-scale attack on the current phlogiston theory of combustion. That year Lavoisier also began a series of experiments on the composition of water which were to prove an important capstone to his combustion theory and win many converts to it. Many investigators had been experimenting with the combination of Henry Cavendish's inflammable air, which Lavoisier termed hydrogen (Greek for ""water-former""), with dephlogisticated air (oxygen) by electrically sparking mixtures of the gases. All of the researchers noted the production of water, but all interpreted the reaction in varying ways within the"
"air that does not support combustion was clear to Rutherford, although he was not aware that it was an element. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as ""burnt air"" or ""phlogisticated air"". Nitrogen gas was inert enough that Antoine Lavoisier referred to it as ""mephitic air"" or ""azote"", from the Greek word (azotikos), ""no life"". In an atmosphere of pure nitrogen, animals died and flames were extinguished. Though Lavoisier's name was not accepted in English, since it was pointed out that almost all gases"
"He also objected to Lavoisier's identification of heat as having a material or elementary basis. Working within the framework of Newtonian mechanism, Cavendish had tackled the problem of the nature of heat in the 1760s, explaining heat as the result of the motion of matter. In 1783 he published a paper on the temperature at which mercury freezes and in that paper made use of the idea of latent heat, although he did not use the term because he believed that it implied acceptance of a material theory of heat. He made his objections explicit in his 1784 paper on"
"invisible substance he termed a ""gas"" or ""wild spirit"" (""spiritus sylvestris""). The properties of carbon dioxide were further studied in the 1750s by the Scottish physician Joseph Black. He found that limestone (calcium carbonate) could be heated or treated with acids to yield a gas he called ""fixed air."" He observed that the fixed air was denser than air and supported neither flame nor animal life. Black also found that when bubbled through limewater (a saturated aqueous solution of calcium hydroxide), it would precipitate calcium carbonate. He used this phenomenon to illustrate that carbon dioxide is produced by animal respiration"
"gases that were usually soluble in water. From these experiments Priestley is credited with discovering many new gases such as oxygen, hydrogen chloride, and ammonia. He also discovered a way to find the purity or “goodness” of air using “nitrous air test”. This test was conducted by mixing nitrous gas with a test sample of another gas and trapping it in the pneumatic trough, essentially the greater the decrease in volume, the more pure the sample of gas was (key principle in eudiometry). Henry Cavendish later used a similar device to determine the fraction of oxygen in the Earth's atmosphere."
"saw damaged lungs, and the publication of Edwin Chadwick's ""The Sanitary Condition of the Labouring Population"" in 1842 caused Leigh to take an interest in public health matters. From the 1840s, he proposed that the high incidence of respiratory disease in Manchester, compared to other areas of England, was due to the city's poor air quality and that this was largely attributable to the extensive use of coal as fuel in what was the first industrial city. Charles James Napier had described Manchester as ""the chimney of the world"" in 1839 and a near-contemporary study of deaths in the city"
"fairly considerable part (0.94% by volume, 1.3% by mass) of the Earth's atmosphere due to decay of radioactive potassium-40. Pierre Janssen and Joseph Norman Lockyer discovered a new element on August 18, 1868 while looking at the chromosphere of the Sun, and named it helium after the Greek word for the Sun, (). No chemical analysis was possible at the time, but helium was later found to be a noble gas. Before them, in 1784, the English chemist and physicist Henry Cavendish had discovered that air contains a small proportion of a substance less reactive than nitrogen. A century later,"
"a closed container. He noted that air rushed in when he opened the container, which indicated that part of the trapped air had been consumed. He also noted that the tin had increased in weight and that increase was the same as the weight of the air that rushed back in. This and other experiments on combustion were documented in his book ""Sur la combustion en général"", which was published in 1777. In that work, he proved that air is a mixture of two gases; 'vital air', which is essential to combustion and respiration, and ""azote"" (Gk. """" ""lifeless""), which"
"the Royal Society's Copley Medal for this paper. Gas chemistry was of increasing importance in the latter half of the 18th century and became crucial for Frenchman Antoine-Laurent Lavoisier's reform of chemistry, generally known as the chemical revolution. In 1783 Cavendish published a paper on eudiometry (the measurement of the goodness of gases for breathing). He described a new eudiometer of his invention, with which he achieved the best results to date, using what in other hands had been the inexact method of measuring gases by weighing them. He next published a paper on the production of water by burning"
"later reinterpreted in terms of positive and negative charges). Franklin also showed that lightning is electricity in 1752. The accepted theory of heat in the 18th century viewed it as a kind of fluid, called caloric; although this theory was later shown to be erroneous, a number of scientists adhering to it nevertheless made important discoveries useful in developing the modern theory, including Joseph Black (1728–99) and Henry Cavendish (1731–1810). Opposed to this caloric theory, which had been developed mainly by the chemists, was the less accepted theory dating from Newton's time that heat is due to the motions of"
"prefiguring thermodynamics. Theoretical physicist Dietrich Belitz concluded that in this work Cavendish ""got the nature of heat essentially right."" As Cavendish performed his famous density of the Earth experiment in an outbuilding in the garden of his Clapham Common estate, his neighbours would point out the building and tell their children that it was where the world was weighed. In honour of Henry Cavendish's achievements and due to an endowment granted by Henry's relative William Cavendish, 7th Duke of Devonshire, the University of Cambridge's physics laboratory was named the Cavendish Laboratory by James Clerk Maxwell, the first Cavendish Professor of"
"the gas that caused the carbonation. In 1764, Irish chemist Dr. Macbride infused water with carbon dioxide as part of a series of experiments on fermentation and putrefaction. In 1766 Henry Cavendish devised an aerating apparatus that would inspire Joseph Priestley to carry out his own experiments with regards to carbonated waters. Cavendish was also aware of Brownrigg's observations at this time and published a paper on his own experiments on a nearby source of mineral water at the beginning of January in the next year. In 1767, Joseph Priestley discovered a method of infusing water with carbon dioxide when"
"In ""Vegetable Staticks"", Hales not only introduced his trough, but also the results he obtained from collected the air, such as the elasticity and composition of airs along with their ability to mix with others. Stephen Hales, called the creator of pneumatic chemistry, created the pneumatic trough in 1727. This instrument was widely used by many chemists to explore the properties of different airs, such as what was called inflammable air (what is modernly called hydrogen). Lavoisier used this in addition to his gasometer to collect gases and analyze them, aiding him in creating his list of simple substances. The"
"the assertion (eventually found to be incorrect) of Carlisle Spedding, the paper's author, that ""this sort of Vapour, or damp Air, will not take Fire except by Flame; Sparks do not affect it, and for that Reason it is frequent to use Flint and Steel in Places affected with this sort of Damp, which will give a glimmering Light, that is a great Help to the Workmen in difficult Cases."" Spedding also introduced the practice of ""coursing the air"". As in other pits, the working areas were ventilated by fresh air, drawn down one half of a partitioned shaft; the"
"wood is composed of ash (pure wood) and phlogiston. Phlogiston was accepted as scientific truth, paralysing the scientific community's ability to discover more, true elements. One scientist even claimed to have isolated phlogiston. A major shareholder in the Bank of England with royal connections, Henry Cavendish was a painfully shy character, who made the vital chemical contribution of discovering the first elemental gas. He added some zinc to spirit of salt (hydrochloric acid) and collected the evanescence given off as bubbles. The gas he collected was tasteless, odourless and colourless, and moreover it produced a squeaky pop in the presence"
"other pneumatic chemists would insist, the air was indeed dynamic, and would not only be influenced by combusted material, but would also influence the properties of different substances. The initial concern of pneumatic chemistry was combustion reactions, beginning with Stephen Hales. These reactions would give off different ""airs"" as chemists would call them, and these different airs contained more simple substances. Until Lavoisier, these airs were considered separate entities with different properties; Lavoisier was responsible largely for changing the idea of air as being constituted by these different airs that his contemporaries and earlier chemists had discovered. This study of"
"had predecessors in the notion that heat was a form of motion. Those predecessors included Francis Bacon, Robert Boyle, Robert Hooke, John Locke, and Henry Cavendish. Rumford had observed the frictional heat generated by boring cannon at the arsenal in Munich. Rumford immersed a cannon barrel in water and arranged for a specially blunted boring tool. He showed that the water could be boiled within roughly two and a half hours and that the supply of frictional heat was seemingly inexhaustible. Rumford confirmed that no physical change had taken place in the material of the cannon by comparing the specific"
"The resulting product was termed ""calx"", which was considered a 'dephlogisticated' substance in its 'true' form. The first strong evidence against phlogiston theory came from pneumatic chemists in Britain during the later half of the 18th century. Joseph Black, Joseph Priestley and Henry Cavendish all identified different gases that composed air; however, it was not until Antoine Lavoisier discovered in the fall of 1772 that, when burned, sulphur and phosphorus “gain[ed] in weight” that the phlogiston theory began to unravel. Lavoisier subsequently discovered and named oxygen, described its role in animal respiration and the calcination of metals exposed to air"
"and precision in his researches into the composition of atmospheric air, the properties of different gases, the synthesis of water, the law governing electrical attraction and repulsion, a mechanical theory of heat, and calculations of the density (and hence the mass) of the Earth. His experiment to measure the density of the Earth has come to be known as the Cavendish experiment. Henry Cavendish was born on 10 October 1731 in Nice, where his family was living at the time. His mother was Lady Anne de Grey, fourth daughter of Henry Grey, 1st Duke of Kent, and his father was"
"Joseph Louis Gay-Lussac, and John Dalton. The pneumatic trough was integral thereon in work with gases (or, as contemporary chemists called them, airs). Work done by Joseph Black, Joseph Priestley, Herman Boerhaave, and Henry Cavendish revolved largely around the use of the instrument, allowing them to collect airs given off by different chemical reactions and combustion analyses. Their work led to the discovery of many types of airs, such as dephlogisticated air (discovered by Joseph Priestley). Moreover, the chemistry of airs was not limited to combustion analyses. During the eighteenth century, many chymists used the discovery of airs as a"
"(O) airs to create water. In 1783, James Watt showed that water was composed of inflammable and dephlogisticated airs, and that the masses of gases before combustion were exactly equal to the mass of water after combustion. Until this point, water was viewed as a fundamental element rather than a compound. James Watt also sought to explore the use of different airs in medical treatments as ""pneumatic therapy"" by collaborating with Dr. Thomas Beddoes to treat his daughter Jessie Watt using fixed air. Joseph Black was a chemist that took interest in the pneumatic field after studying under William Cullen."
"was also the source of acidity. The next year, he named this portion oxygen (Greek for acid-former), and the other azote (Greek for no life). Lavoisier thus has a claim to the discovery of oxygen along with Priestley and Scheele. He also discovered that the ""inflammable air"" discovered by Cavendish - which he termed hydrogen (Greek for water-former) - combined with oxygen to produce a dew, as Priestley had reported, which appeared to be water. In ""Reflexions sur le Phlogistique"" (1783), Lavoisier showed the phlogiston theory of combustion to be inconsistent. Mikhail Lomonosov independently established a tradition of chemistry in"
"air"" (miasma theory) that had contacted his surgical instruments, clothing and bedding, and moreover, these dark humors could be eradicated by heat and noise. Based on his flawed idea Dr. Dinwiddie began a daily practice of placing his surgical bedding and instruments into a large pot of boiling pine tea. When the steam (in his mind the 'dark humors' or 'bad air') came to the surface, he would ring a cow bell to frighten them away. Dr. Dinwiddies' infection rates plummeted. While his model of induced bacterial necrosis was flawed, his practice greatly reduced mortality amongst his patients, as boiling"
"operation in Belfast. The success of his innovative use of stoves to move hot air led him to develop a convection heating system for use in human environments, and by the end of the 1880s his Sirocco stoves were in popular use in schools, church halls and workrooms. He developed his invention further with the introduction in 1898 of a forward-bladed centrifugal fan, which was significantly more powerful than conventional fan designs. This innovation, originally designed for drying tea, evolved into the first air conditioning system. The powerful force of moving hot air across a room with one of his"
"Cavendish. In 1785, he described the irregular movement of coal dust on the surface of alcohol and therefore has a claim as discoverer of what came to be known as Brownian motion. Ingenhousz was elected a Fellow of the Royal Society of London in 1769. In 1799, Ingenhousz died at Bowood House, Calne, England, and was buried in the churchyard of St Mary the Virgin, Calne. His wife died the following year. Jan Ingenhousz Jan Ingenhousz or Ingen-Housz FRS (8 December 1730 – 7 September 1799) was a Dutch physiologist, biologist and chemist. He is best known for discovering photosynthesis"
"for collecting several new water-soluble airs. This was achieved primarily by his substitution of mercury for water, and implementing a shelf under the head for increased stability, capitalizing on the idea Cavendish proposed and popularizing the mercury pneumatic trough. While not credited for direct research into the field of pneumatic chemistry, Boerhaave (teacher, researcher, and scholar) did publish the ""Elementa Chimiae"" in 1727. This treatise included support for Hales' work and also elaborated upon the idea of airs. Despite not publishing his own research, this section on airs in the ""Elementa Chimie"" was cited by many other contemporaries and contained"
"oxygen, ‘inflammable air’ became hydrogen, but the nomenclature of compounds was also put on a more logical footing as ‘oil of vitriol’ became sulphuric acid, ‘philosophical wool’ became zinc oxide and ‘astringent mars saffron’ became iron oxide. Unfortunately, whilst Lavoisier had rid the world of the phlogiston paradigm, he introduced two new erroneous elements now known to be pure energy: lumière and calorique; light and heat. In revenge for his sympathies with the revolutionaries in France, Priestley's home in England was targeted by arsonists in 1791, luckily he escaped thanks to a tip-off, but decided to flee to America. Lavoisier's"