(Excerpt from Annales de Chimie Et de Physique, 1826, Vol....)
Excerpt from Annales de Chimie Et de Physique, 1826, Vol. 33 Chez crochabd Libraire, cloître Saint - Benoît n° 16, près la une des Malhurins. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
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Gay-Lussac was born in 1778 at Saint-Léonard-de-Noblat in the present-day department of Vienne, Austria. He was the eldest of five children of Antoine Gay, lawyer and procureur royal at St. Léonard, and Leonarde Bourigner. Joseph Louis, although baptized “Gay, ” adopted the same practice. The comfortable social and economic position of the family was rudely disturbed by the Revolution.
His father sent him to a boarding school in Paris to prepare him to study law. He passed the entrance examination for the newly founded École Polytechnique, where students’ expenses were paid by the state. Gay-Lussac proved to be an exemplary student during his studies there from 1797 to 1800. Upon graduation, he entered the prestigious École Nationale des Ponts et Chaussées (School of Bridges and Highways). He withdrew from this school in 1801 to become chemist Claude-Louis Berthollet’s research assistant.
On the creation of the Paris Faculty of Science in 1808, Gay-Lussac was appointed professor of physics; in 1832 he gave up this chair in favor of that of general chemistry at the Museum National d’Histoire Naturelle. Nearly all of Gay-Lussac’s life was devoted to pure and applied science, but he did have a brief political career.
He was elected to the Chamber of Deputies in 1831, 1834, and 1837 but resigned on a matter of principle in 1838.
On 7 March 1839, having earlier refused a title from Charles X, he was honored by Louis Philippe with nomination to the upper house. Gay-Lussac’s first major research was carried out with the encouragement of Berthollet and Laplace in the winter of 1801-1802.
There was conflicting evidence about the expansive properties of different gases when heated.
Gay-Lussac improved on most earlier work by taking precautions to exclude water vapor from his apparatus and to use dry gases.
After examining a variety of gases, including several soluble in water, and repeating each experiment several times, he concluded that equal volumes of all gases expand equally with the same increase of temperature.
Similar research was carried out independently by Dalton at about the same time.
Dalton’s work, however, was considerably less accurate.
About 1787 J. A. C. Charles had recognized the equal expansion of several gases but had never bothered to publish his findings.
Although the quantitative law of thermal expansion is often called “Charles’s law, ” Charles did not measure the coefficient of expansion; moreover, for soluble gases, he had found unequal expansion. Gay-Lussac made an ascent in a hydrogen balloon with Biot on 24 August 1804.
The primary objective of the ascent was to see whether the magnetic intensity at the earth’s surface decreased with an increase in altitude. They concluded that it was constant up to 4, 000 meters.
They also carried long wires to test the electricity of different parts of the atmosphere.
Another objective was to collect a sample of air from a high altitude to compare its composition with that of air at ground level.
Gay-Lussac made a second ascent, on 16 September 1804, but this time by himself, in order to lessen the weight of the balloon and thus reach a greater height. He was able to repeat observations of pressure, temperature, and humidity and also make magnetic measurements.
His subsequent analysis of these samples showed that the proportion of oxygen was identical with that in ordinary air.
Gay-Lussac reached a calculated height of 7, 016 meters above sea level, a record not equaled for another half century. One of Gay-Lussac’s early collaborators was Alexander von Humboldt.
Nearly ten years older than Gay-Lussac, Humboldt already had an international reputation as an explorer; yet he learned something about precision in scientific research from Gay-Lussac, who in turn had his horizons broadened by his German friend.
They collaborated in an examination of various methods of estimating the proportion of oxygen in the air, particularly the use of Volta’s eudiometer. 3 In this method the gas being, tested (which was required to contain some oxygen) was sparked with hydrogen to form water vapor, which condensed. The resulting contraction permitted an estimate of the proportion of oxygen in the sample.
This method obviously presupposed a knowledge of the relative proportions by volume in which hydrogen and oxygen combine to form water; one of the principal objects of the work of Gay-Lussac and Humboldt was to determine the proportion with the greatest possible accuracy.
They also determined the limiting proportions for an explosion to be possible.
After carrying out a large number of experiments with an excess of first one gas and then the other, they calculated -making allowance for a slight impurity in the test oxygen - that 100 parts by volume of oxygen combined with 199. 89 parts of hydrogen or, they said, in round numbers, 200 parts.
Gay-Lussac clearly expressed his preference for volumes, pointing out that the presence of moisture, which would be difficult to estimate gravimetrically, did not alter the volumetric ratio.
This memoir made a useful contribution to science not only for its accuracy but as a precursor of Gay-Lussac’s famous research on the combining volumes of gases. In March 1805 Gay-Lussac embarked on a year of European travel with Humboldt, going first to Rome and ending in Berlin.
During this journey Gay-Lussac carried out various chemical analyses.
Their principal object, however, was to record the magnetic elemertti at different points along their route. To obtain the magnetic intensity, the period of oscillation of a magnetized needle was determined.
The magnetic intensity was then found to be proportional to the square of the number of oscillations made by the needle, displaced slightly from the magnetic meridian, in a given time.
They did not think that magnetic intensity in any one place changed with time, since on taking readings at Milan on entering and leaving Italy at an interval of six months, they found no difference.
A series of prolonged experiments to determine diurnal variation, both on Mount Cenis and in Rome, had not revealed any difference at different hours of the day and night.
As regards the general accuracy of their readings, many of which were made under conditions that were far from ideal, they estimated that the greatest discrepancy between their angular readings could not have been more than ten minutes of arc.
Their general conclusion was that the horizontal component of the earth’s magnetic intensity increased from north (Berlin) to south (Naples) but that the total intensity decreased on approaching the equator. In 1807 Gay-Lussac carried out a series of experiments designed principally to see whether there was a general relationship between the specific heats of gases and their densities. He measured the change in the temperature of a gas (and thus heat capacity) as a function of density changes produced by the free expansion of the gas.
From a modern viewpoint the importance of his work was his establishment of a basic principle of physics, since it follows from his experiments that (in modern terms) the internal energy of an ideal gas depends on the temperature only.
He took two twelve-liter, double-neck flasks.
It was known that compression of gases was accompanied by evolution of heat and expansion by absorption of heat.
Gay-Lussac, however, wished to find the relationship between heat absorbed and heat evolved in the two flasks, and from his experiments he drew the valuable conclusion that these were equal within the limits of experimental error.
The change of temperature was, moreover, directly proportional to the change of pressure.
For Gay-Lussac himself, the law provided a vindication of his belief in regularities in the physical world, which it was the business of the scientist to discover.
Gay-Lussac began his memoir by pointing out the unique character of the gaseous state6 For solids and liquids a particular increase in pressure would produce a change different in each case; it was only matter in the gaseous state that increased equally in volume for a given increase of pressure.
His own statement was that “gases combine in very simple proportions…and the apparent contraction in volume which they experience on combination has also a simple relation to the volume of the gases, or at least to one of them. ”
He gives the following examples of the simple ratios of combining volumes of gases (modern symbols are used for brevity).
These neat ratios do not, however, correspond exactly to his experimental results.
He deduced his law from a few fairly clear cases (particularly the first few listed above) and glossed over discrepancies in some of the others.
The simple reaction between hydrogen and chlorine, which is often used today as an elementary illustration of the law, was not discovered until 1809 and was included only as a footnote when this memoir was printed. Gay-Lussac presented his law of combining volumes of gases as a natural consequence of his collaboration with Humboldt, with whom he had found that 100 parts by volume of oxygen combine with almost exactly 200 parts of hydrogen.
That his work of January 1805 with Humboldt led naturally to the law of combining volumes may be logically true but historically the connection is less direct.
One has to explain the interval of nearly four years between obtaining the first data and the announcement of the law.
Probably something had happened earlier in the year 1808 that made Gay-Lussac turn his attention back to his earlier work and realize that the value he had obtained for the combining volumes of hydrogen and oxygen was more than a coincidence and was in fact only one example of a general phenomenon.
In the autumn of 1808 Gay-Lussac and Thenard had discovered boron trifluoride.
They were particularly impressed by one of the properties of this new gas, the dense fumes produced when it came into contact with the air; they compared these fumes with the fumes produced by the reaction of muriatic-acid gas and ammonia.
It seems likely that Gay-Lussac, struck by the reaction of boron trifluoride with moist air, tried its reaction with other gases including ammonia.
An obvious reaction for for comparison would be that between hydrochloric-acid gas and ammonia.
This reaction was given special prominence in the memoir on combining volumes of gases. One of the points of strength of the memoir was that it took data from a wide variety of reputable sources.
This was no suspect generalization based on the biased experimental work of its author.
In many cases the analyses that had appeared in the chemical literature had given only the gravimetric composition, and Gay-Lussac, taking reliable data for the density, had to convert this to a volumetric ratio.
A close examination of the provenance of the density data shows that much was derived from his associates in the Société d’Arcueil.
The influence of Berthollet is particularly prominent in Gay-Lussac’s attempt to reconcile the opinions of Dalton, Thomson, and Wollaston on definite and multiple proportions with Berthollet’s known conviction that compounds can always be formed in variable proportions except in special circumstances.
It was possible to argue that the gaseous state provided such an exception, and Berthollet accepted Gay-Lussac’s law.
Considering the implications of the law for the atomic structure of matter, it would be reasonable to expect Dalton to have welcomed the law of combining volumes as additional evidence for his atomic theory.
Dalton, however, refused to accept the accuracy of the results of the French chemist.
The Italian physical chemist Avogadro, on the other hand, not only accepted Gay-Lussac’s work but developed its implications for the relationship between the volumes of gases and the number of molecules they contain.
His great debt to Gay-Lussac’s memoir was explicit. Although Berzelius and Gay-Lussac differed in the actual values given to “volume weights” (often by a factor of 2), Berzelius, especially in his earlier work, regarted Gay-Lussac’s method of speaking of volumes as preferable to Dalton’s atoms.
Gay-Lussac himself was prepared to estimate the relative vapor density of mercury not by direct means but by calculation based on the weight combining with a given weight of oxygen in the solid state, Gay-Lussac later speculated about the proportion of “carbon vapor” in carbon compounds.
The apparatus was improved half a century later by A. W. Hofmann, and the method by which the volume of a given weight of a vaporized substance is found is now usually known as Hofmann’s method. The work of Volta inspired many chemists to investigate the chemical effects of the voltaic pile.
Gay-Lussac and Thenard were among this number.
They were influenced particularly by the news in the winter of 1807–1808 of Davy’s isolation of potassium and sodium by the use of the giant voltaic pile at the Royal Institution.
Napoleon ordered the construction of an even larger pile at the École Polytechnique and Gay-Lussac and Thenard were placed in charge of it.
Although Davy seems to have exhausted the most obvious possibilities, Gay-Lussac and Thenard’s report does contain the suggestion that the rate of decomposition of an electrolyte depends only on the strength of the current (and not, for example, on the size of the electrodes), and they used chemical decomposition as a measure of electric current thirty years before Faraday.
The two young Frenchmen, no doubt under the influence of Berthollet, had reasoned that the action of great heat should change the usual affinities.
Thinking that the normal affinities of oxygen for iron and the alkali metals could thus be reversed, they fused the respective alkalies with iron filings subjected to a bright red heat in a bent iron gun barrel.
The metal vapor distilled over into a receiver luted to the gun barrel.
In this way they prepared samples of about twenty-five grams of each metal at a low cost. They were then able to investigate the physical constants of potassium, finding its specific gravity to be 0. 874 (modern value, 0. 859 at 0°c).
Davy had been unable to produce a better result than 0. 6.
Gay-Lussac and Thenard also discovered the alloy of potassium and sodium that exists as a liquid at room temperature.
They then began a program of research in which potassium was not the end product but a reagent used to make further discoveries.
In particular, they investigated the reaction between potassium metal and various gases.
They found that when potassium is strongly heated in hydrogen, it combines with it to form a gray solid, potassium hydride, which is decomposed by water.
They proposed the use of heated potassium as a means of performing an accurate volumetric analysis of nitrous and nitric oxides.
The data obtained in this way by Gay-Lussac about the composition of nitric oxide was used by him later as evidence for his law of combining volumes of gases.
They found that heated potassium metal decomposed muriatic-acid gas, forming the muriate of potash and hydrogen.
Unfortunately they were prevented from reaching the conclusion that the gas was a simple compound of hydrogen and the muriatic radical by the conviction that the reaction was really due to water vapor in the gas. In a further memoir, Gay-Lussac and Thenard described an experiment in which potassium was heated in dry ammonia, forming a solid (KNH 2)2 and liberating hydrogen.
Other related experiments seemed to indicate to them that potassium was not an element at all but a hydride, and they argued this at length with Davy.
Despite their mistaken conclusions on this point, the French chemists deserve credit for their discovery of a new class of compounds, the amides of metals. In their next memoir Gay-Lussac and Thenard made further use of potassium as a reagent, this time to decompose boric acid. They were not, however, alone in this field, since in the early summer of 1808 Davy turned his attention to their method of using potassium as a reagent.
In a memoir read to the Royal Society on 30 June 1808, Davy described in a footnote how he had ignited boric acid and heated the product with potassium in a gold tube; this process yielded a black substance, which he did not identify but which was later recognized to be boron.
It was not until his fourth Bakerian lecture, read on 15 December 1808, that Davy made any claim to the discovery of a new substance.
His experimental work was rather poor and hurried.
He admitted that he had had a report that Thenard was investigating the decomposition of boric acid by potassium.
In December 1808 Davy succeeded in decomposing boric acid.
On 20 June 1808 they had mentioned an olive-gray substance obtained by the action of potassium on fused boric acid, but it was not until 14 November that they claimed to have isolated a new element and discovered its properties.
This is one case where the work of Gay-Lussac and Thenard is indubitably prior to that of Davy.
Equal weights of potassium metal and fused boric acid were heated together in a copper tube, thus producing a mixture of potassium, potassium borate, and boron, The new element did not dissolve or react chemically with water; this property thus provided a method of separating it.
Gay-Lussac and Thenard gave it the name bore (“boron” and noted the similarity of its properties to those of carbon, phosphorus, and sulfur.
Boron was found to form borides similar to carbides. Their success in decomposing boric acid and isolating its “radicals” led Gay-Lussac and Thenard to apply their new reagent, potassium, to the isolation of other radicals.
Investigating the properties of their fluoric acid, they found it had no effect on glass (a well-known property of hydrofluoric acid), and they reasoned correctly that this must be because it was already combined with an element similar to the basis of silica, namely, the boron from the acid used in its preparation.
They therefore named the gas fluoboric gas (boron trifluoride).
They were now ready to prepare true hydrofluoric acid and attempt its decomposition.
This was all the more unexpected since sunlight decomposed it so easily.
This led them to carry out further experiments on the effect of light on chemical reactions.
They prepared two mixtures of chlorine and hydrogen; one was placed in darkness and the other in feeble sunlight.
The first mixture was still greenish yellow in color after several days, but the second had reacted completely by the end of a quarter of an hour, judging by the disappearance of the color of the chlorine.
The experiment was repeated with olefiant gas (ethylene) and oxymuriatic-acid gas, which were mixed and left for two days in total darkness.
As soon as the mixture was exposed to bright sunlight, there was a violent explosion.
This confirmed their hypothesis that the speed of the reaction was proportional to the intensity of the light. Apart from their early contribution to photochemistry, Gay-Lussac and Thenard made a fundamental contribution to the realization that so-called oxymuriatic acid contained no oxygen and was an element.
Their memoir, read at a meeting of the Institute on 27 February 1809, contains the following remark, the wording of which should be carefully noted: Oxygenated muriatic acid is not decomposed by charcoal, and it might be supposed from this fact and those which are communicated in this memoir, that this gas is a simple body.
The phenomena which it presents can be explained well enough on this hypothesis; we shall not seek to defend it, however, as it appears to us that they are still better explained by regarding oxygenated muriatic acid as a compound body.
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(Excerpt from Annales de Chimie Et de Physique, 1826, Vol....)
He received his early education at the hands of the Catholic Abbey of Bourdeix, though later in life became an atheist.
He was a member of the Société d’Arcueil and the Societé Philomatique. In 1821, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1831 he was elected to represent Haute-Vienne in the chamber of deputies, and in 1839 he entered the chamber of peers. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1832.
Gay-Lussac married Geneviève-Marie-Joseph Rojot in 1809. He had first met her when she worked as a linen draper's shop assistant and was studying a chemistry textbook under the counter. He fathered five children.
