scholarly journals A pilha de Daniell: um estudo de caso histórico

2021 ◽  
Vol 38 (3) ◽  
pp. 1650-1673
Author(s):  
Mayra Cristina da Silva Costa ◽  
Paulo Alves Porto
Keyword(s):  
Royal Society ◽  
Michael Faraday

O modelo didático da pilha de Daniell tem papel central no ensino de eletroquímica, associado a conceitos fundamentais, tais como as reações de oxirredução. O dispositivo criado originalmente por John F. Daniell (1790-1845), porém, apresenta diferenças em relação ao modelo didático difundido na atualidade. Este artigo apresenta um estudo de caso histórico sobre o desenvolvimento da pilha por Daniell em meados do século XIX. A análise das comunicações de Daniell acerca desse assunto à Royal Society revelam a influência de Michael Faraday e William Snow Harris sobre seus trabalhos. Foram necessários cerca de dez anos para que Daniell chegasse à versão final de sua pilha, com um eletrodo de zinco amalgamado em um eletrólito de ácido sulfúrico diluído, e outro eletrodo de cobre em contato com uma solução ácida de sulfato de cobre. A separação entre os eletrólitos, inicialmente feita com uma membrana de origem animal, foi posteriormente feita por um recipiente de argila porosa. Essa pilha, capaz de fornecer corrente contínua de maneira constante por um tempo considerável, foi fundamental para a expansão das redes telegráficas nessa época. A compreensão do processo de desenvolvimento do conhecimento científico e tecnológico, e de suas implicações para a sociedade, por meio de um estudo de caso histórico, pode trazer contribuições relevantes para o ensino de ciências na atualidade.

VI. Fifth letter on voltaic combinations, with some account of the effects of a large constant battery. Addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J. Frederic Daniell, Esq. F. R. S., Prof. Chem. in King's College, London

1839 ◽  
Vol 129 ◽  
pp. 89-95 ◽  
Keyword(s):  
Royal Society ◽  
Conducting Surface ◽  
Conducting Sphere ◽  
Active Point ◽  
King's College ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

My dear Faraday, In my last letter to you, which the Royal Society have done me the honour to publish in the Philosophical Transactions for 1838, I observed, that “the principal circumstance which might be supposed to limit the power of an active point within a conducting sphere, in any given electrolyte, is the resistance of that electrolyte, which increases in a certain ratio to its depth or thickness.” The superficial measure of the conducting sphere, and the distance of the generating metal, or the depth and resistance of the electrolyte, are, in fact, the variable conditions in a voltaic combination upon which its efficiency depends; and their relations require further investigation before we shall be able to determine what may be the proper proportions for the economical application of the power to useful purposes. I shall venture, therefore, to trouble you with the results of some further experiments upon the subject, and upon different combinations of the constant battery, before I proceed to communicate some observations upon Electrolysis, which I trust you will find not without interest, and to which, according to my plan, my attention has been lately exclusively directed. Looking, for a moment, upon the affinity which circulates in the battery as a radiant force, it seemed desirable to ascertain what would be the result of intercepting the rays by the conducting surface nearer to their centre than in the arrangements which have been previously described, as the relation of the generating and conducting metals to each other might be thereby more clearly ascertained.

scholarly journals XI. Second letter on the electrolysis of secondary compounds. Addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J . Frederic Daniell, Esq. F. R. S. For. Sec. R. S., Prof. Chem. in King's College, London

1840 ◽  
Vol 130 ◽  
pp. 209-224
Keyword(s):  
Royal Society ◽  
Chemical Elements ◽  
Pure Water ◽  
Secondary Compounds ◽  
King's College ◽  
Usual Manner ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday ◽  
Epsom Salt

My dear Faraday, You will not, I think, be surprised or displeased at my addressing you again upon the Electrolysis of Secondary Compounds . The whole of my very limited leisure, since my last Letter which the Royal Society did me the honour to publish in the Philosophical Transactions for 1839, has been occupied with experiments upon the subject; and I have obtained some results which I trust will not be found unworthy of the continued attention of yourself and the Society. The mode of investigation which I have adopted seems to me calculated not only to throw light upon the nature of electrolytes, but upon the mode in which the chemical elements group themselves together to constitute Radicles or Proximate Principles , the question which now seems universally to occupy the attention of chemists. I feel more than ever satisfied that the laws of electrolysis will be found to lead to the solution of this great problem. Upon reflecting upon the constitution of the oxyacid salts, as developed in my last Letter, I conceived that it might be possible to obtain further evidence that the simple cathion travelled as a metal to the platinode, while the compound anion was passing in the opposite direction; and that means might be devised of stopping it, as it were, in transitu . Your beautiful experiment, which I have often repeated with success, of precipitating the magnesia from a solution of Epsom salt against a surface of pure water, in the course of a voltaic current, suggested the mode of proceeding. According to my view of that experiment, the first electrolyte was resolved into the compound anion, sulphuric acid + oxygen, which passed to the zincode; and the simple cathion, magnesium, which on its passage to the platinode was stopped at the surface of water, from not finding any ion , by temporarily combining with which it could be further transferred according to the laws of electrolysis. At this point, therefore, it gave up its charge to the hydrogen of the water, which passed in the usual manner to the platinode; and the circuit was completed by the decomposition of this second electrolyte. The corresponding oxygen, of course, met the magnesium at the point where it was arrested in its progress, and, combining with it, magnesia was precipitated.

Relics of Davy and Faraday in New Zealand

1998 ◽  
Vol 52 (1) ◽  
pp. 93-102 ◽  
Author(s):  
G. J. Tee
Keyword(s):  
New Zealand ◽  
Royal Society ◽  
Place Names ◽  
Royal Institution ◽  
Humphry Davy ◽  
Michael Faraday ◽  
Royal Society Of London

In April 1997 Sir John Meurig Thomas, F.R.S., toured New Zealand, as the 1997 Rutherford Lecturer of the Royal Society of London. He delivered his Rutherford Lecture on Sir Humphry Davy, P.R.S. (1778–1829), and Michael Faraday, F.R.S. (1791–1867), the first and second Directors of the Royal Institution. Many place–names in New Zealand commemorate scientists. There is Mount Davy (1012 m) at 42°23'S, 171°23'E, between Greymouth and Blackball. Mount Faraday, at 42°03'S, 171°30'E, is the highest peak (1485 m) in the Paparoa Range (south of Westport), whose successive peaks from south to north are named Mounts Lodge, Ramsay, Dewar, Priestly, Faraday, Curie, Einstein, Euclid and Kelvin. And Mount Copernicus and Mount Galileo are 10 km east of the Paparoa Range.

scholarly journals Sir Humphry Davy and the coal miners of the world: a commentary on Davy (1816) ‘An account of an invention for giving light in explosive mixtures of fire-damp in coal mines’

2015 ◽  
Vol 373 (2039) ◽  
pp. 20140288 ◽  
Author(s):  
John Meurig Thomas
Keyword(s):  
Royal Society ◽  
Coal Mines ◽  
Coal Industry ◽  
Coal Miners ◽  
Literary Expression ◽  
The North ◽  
Royal Institution ◽  
Humphry Davy ◽  
Michael Faraday ◽  
Newcastle Upon Tyne

In the period between 1815 and 1818, Sir Humphry Davy read four papers to the Royal Society and published a monograph dealing with a safety lamp for coal miners, all of which record in detail the experimental work that he carried out, with his assistant Michael Faraday, so as to determine how to prevent catastrophic accidents in coal mines by the explosion of fire-damp (methane) in the presence of a naked flame. This article describes the key experiments that he performed at the Royal Institution and some of the subsequent trials made in the coal mines of the north of England. It begins, however, with an account of Davy's prior achievements in science before he was approached for help by the clergymen and doctors in the Gateshead and Newcastle upon Tyne areas. There is little doubt that the Davy lamp, from the 1820s onwards, transformed the coal industry worldwide. It also profoundly influenced the science of combustion, and in the words of a pioneer in that field, W. A. Bone, FRS, ‘There is no better model of logical experimental procedure, accurate reasoning, philosophical outlook and fine literary expression.’ It is a remarkable fact that it took Davy essentially only two weeks from the time he was given samples of fire-damp to solve the problem and to devise his renowned miner's safety lamp. A brief account is also given of the contemporaneous invention of a safety lamp by George Stephenson, and of some of Davy's subsequent accomplishments. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society .

scholarly journals X. Further observations on voltaic combinations. In a letter addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, Corr. Memb. Royal & Imp. Acadd. of Sciences, Paris Petersburgh, &c

1837 ◽  
Vol 127 ◽  
pp. 141-160 ◽  
Keyword(s):  
Royal Society ◽  
Saturated Solution ◽  
Average Amount ◽  
Standard Acid ◽  
Royal Institution ◽  
The Subject ◽  
Principal Subject ◽  
Michael Faraday ◽  
Mixed Gases

My dear Faraday, I Had intended, ere this, to have addressed you upon the subject of the measure of affinity which the constant battery may be made to supply, as indicated by the con­cluding experiment of my last letter; but my attention has been diverted, and the whole of my leisure occupied by what I found to be a necessary preliminary investi­gation of the effects of changes of temperature upon the voltaic action. In the course of my experiments upon this principal subject, I have also been led to observe some curious disturbances and diversions of the battery current, from secondary combina­tions; and I now submit the results of the whole inquiry to your judgment, not without a hope that you may consider them of sufficient interest and importance to be communicated to the Royal Society. You may perhaps recollect that the standard charge, which I finally adopted in the use of the constant battery, was a mixture of eight parts of water with one of oil of vitriol on the side of the zinc, and a saturated solution of sulphate of copper in contact with the copper; and that the average amount of its work, as measured by the voltameter, was 11 cubic inches of mixed gases per five minutes. It occurred to me that the resistance to the current might again be reduced by dissolving the salt in the standard acid instead of water; and upon making the experiment I found the action increased from 11 cubic inches to 13 cubic inches, at which rate it steadily maintained itself; the following being the result of one series of observations.

Humphry Davy, nitrous oxide, the Pneumatic Institution, and the Royal Institution

2014 ◽  
Vol 307 (9) ◽  
pp. L661-L667 ◽  
Author(s):  
John B. West
Keyword(s):  
Nitrous Oxide ◽  
William Wordsworth ◽  
Royal Society ◽  
Samuel Taylor Coleridge ◽  
Royal Institution ◽  
History Of ◽  
Humphry Davy ◽  
Respiratory Gases ◽  
Joseph Black ◽  
Michael Faraday

Humphry Davy (1778–1829) has an interesting place in the history of respiratory gases because the Pneumatic Institution in which he did much of his early work signaled the end of an era of discovery. The previous 40 years had seen essentially all of the important respiratory gases described, and the Institution was formed to exploit their possible value in medical treatment. Davy himself is well known for producing nitrous oxide and demonstrating that its inhalation could cause euphoria and heightened imagination. His thinking influenced the poets Samuel Taylor Coleridge and William Wordsworth, and perhaps we can claim that our discipline colored the poetry of the Romantic Movement. Davy was also the first person to measure the residual volume of the lung. The Pneumatic Institution was the brainchild of Thomas Beddoes, who had trained in Edinburgh under Joseph Black, who discovered carbon dioxide. Later Davy moved to the Royal Institution in London formed, in part, to diffuse the knowledge of scientific discoveries to the general public. Davy was a brilliant lecturer and developed an enthusiastic following. In addition he exploited the newly described electric battery to discover several new elements. He also invented the safety lamp in response to a series of devastating explosions in coal mines. Ultimately Davy became president of the Royal Society, a remarkable honor for somebody with such humble origins. Another of his important contributions was to introduce Michael Faraday (1791–1867) to science. Faraday became one of the most illustrious British scientists of all time.

From engineer to scientist: reinventing invention in the Watt and Faraday centenaries, 1919–31

2007 ◽  
Vol 40 (3) ◽  
pp. 389-411 ◽  
Author(s):  
CHRISTINE MACLEOD ◽  
JENNIFER TANN
Keyword(s):  
Twentieth Century ◽  
Royal Society ◽  
Electromagnetic Induction ◽  
Scientific Research ◽  
Important Research ◽  
Natural Philosopher ◽  
Steam Power ◽  
History Of ◽  
Michael Faraday

AbstractWhile important research on the history of scientific commemorations has been published in recent years, relatively little attention has been paid to the commemoration of invention and inventors. A comparison of the centenaries of James Watt's death in 1919 and of Michael Faraday's discovery of electromagnetic induction in 1931 reveals how the image of the inventor was being refashioned in the early twentieth century. Although shortly after his death Watt had been acclaimed by the Royal Society as a great ‘natural philosopher’, a century later his reputation had been appropriated by the engineering professions and trades. As the title of Dickinson's 1935 biography described him, he was seen primarily as a ‘craftsman and engineer’, not a scientist. With poor publicity, which failed in particular to make any connection between steam power and electricity, the 1919 centenary excited little interest outside engineering circles. Meanwhile, professional scientists, who were seeking financial recognition for the importance of their research in ‘pure’ science, had found a new icon in Michael Faraday. They seized the occasion of the 1931 centenary to reinforce the link between Faraday's scientific research and the wonders of modern electrical technology and thereby to elevate the role of ‘blue-sky’ research over its ‘mere’ application.

XI. Additional observations on voltaic combinations. In a letter addressed to Michael Faraday, D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, Corr. Memb. Royal & Imp. Acadd. of Science, Paris, Petersburgh, &c. By J. Frederic Daniell, F. R. S., Prof. Chem. in King's College, London

1836 ◽  
Vol 126 ◽  
pp. 125-129 ◽  
Keyword(s):  
Royal Society ◽  
King's College ◽  
Royal Institution ◽  
The Common ◽  
Michael Faraday

My Dear Faraday, The Council of the Royal Society having done me the honour to order the publication of my observations upon “Voltaic Combinations” in the Philosophical Transactions, I should wish to add the results of some further researches, which may render the account of the constant voltaic battery more complete and practically useful. My great object in this combination was to obtain an invariable current of force sufficient to effect chemical decompositions, after overcoming the resistance necessary to register its quantity by the voltameter; and having succeeded in this, it seemed to me almost a matter of indifference to the solution of the various important questions to which it might be applied, whether the quantity were large or small. I quickly, however, discovered that the battery might be rendered not only perfectly steady in action but very powerful; and that it would be extremely efficient and convenient for all the purposes to which the common voltaic battery is usually applied. I set myself therefore to perfect its construction with this view.

Single molecule microscopy and spectroscopy: concluding remarks

2015 ◽  
Vol 184 ◽  
pp. 475-484
Author(s):  
Niek F. van Hulst
Keyword(s):  
Single Molecule ◽  
Royal Society ◽  
Control Synthesis ◽  
Stained Glass ◽  
Ambient Conditions ◽  
Single Molecule Microscopy ◽  
Opposite Electrode ◽  
Electrical Component ◽  
Michael Faraday ◽  
Scientific Debates

Chemistry is all about molecules: control, synthesis, interaction and reaction of molecules. All too easily on a blackboard, one draws molecules, their structures and dynamics, to create an insightful picture. The dream is to see these molecules in reality. This is exactly what “Single Molecule Detection” provides: a look at molecules in action at ambient conditions; a breakthrough technology in chemistry, physics and biology. Within the realms of the Royal Society of Chemistry, the Faraday Discussion on “Single Molecule Microscopy and Spectroscopy” was a very appropriate topic for presentation, deliberation and debate. Undoubtedly, the Faraday Discussions have a splendid reputation in stimulating scientific debates along the traditions set by Michael Faraday. Interestingly, back in the 1830's, Faraday himself pursued an experiment that led to the idea that atoms in a compound were joined by an electrical component. He placed two opposite electrodes in a solution of water containing a dissolved compound, and observed that one of the elements of the compound accumulated on one electrode, while the other was deposited on the opposite electrode. Although Faraday was deeply opposed to atomism, he had to recognize that electrical forces were responsible for the joining of atoms. Probably a direct view on the atoms or molecules in his experiment would have convinced him. As such, Michael Faraday might have liked the gathering at Burlington House in September 2015 (Fig. 1). Surely, with the questioning eyes of his bust on the 1st floor corridor, the non-believer Michael Faraday has incited each passer-by to enter into discussion and search for deeper answers at the level of single molecules. In these concluding remarks, highlights of the presented papers and discussions are summarized, complemented by a conclusion on future perspectives.The Royal Society of Chemistry at Burlington House in London. The entrance and the stained glass window on the stairway towards the first floor corridor where one finds the bronze bust representing Michael Faraday, protagonist of the early-day lively scientific discussions, which have inspired the “Faraday Discussions”.

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