Faraday as a Discoverer - John Tyndall (children's ebooks online txt) 📗

personal good and pleasure on me; and then as one able to convey the truth and principle of those boundless fields of knowledge which concern natural things to the young, untaught, and inquiring mind.

 

‘You may imagine my delight when I came to know Mrs. Marcet personally; how often I cast my thoughts backward, delighting to connect the past and the present; how often, when sending a paper to her as a thank-offering, I thought of my first instructress, and such like thoughts will remain with me.

 

‘I have some such thoughts even as regards your own father; who was, I may say, the first who personally at Geneva, and afterwards by correspondence, encouraged, and by that sustained me.’

 

Twelve or thirteen years ago Mr. Faraday and myself quitted the Institution one evening together, to pay a visit to our friend Grove in Baker Street. He took my arm at the door, and, pressing it to his side in his warm genial way, said, ‘Come, Tyndall, I will now show you something that will interest you.’ We walked northwards, passed the house of Mr. Babbage, which drew forth a reference to the famous evening parties once assembled there. We reached Blandford Street, and after a little looking about he paused before a stationer’s shop, and then went in. On entering the shop, his usual animation seemed doubled; he looked rapidly at everything it contained. To the left on entering was a door, through which he looked down into a little room, with a window in front facing Blandford Street. Drawing me towards him, he said eagerly, ‘Look there, Tyndall, that was my working-place. I bound books in that little nook.’ A respectable-looking woman stood behind the counter: his conversation with me was too low to be heard by her, and he now turned to the counter to buy some cards as an excuse for our being there. He asked the woman her name—her predecessor’s name— his predecessor’s name. ‘That won’t do,’ he said, with good-humoured impatience; ‘who was his predecessor?’ ‘Mr. Riebau,’

she replied, and immediately added, as if suddenly recollecting herself, ‘He, sir, was the master of Sir Charles Faraday.’

‘Nonsense!’ he responded, ‘there is no such person.’ Great was her delight when I told her the name of her visitor; but she assured me that as soon as she saw him running about the shop, she felt-though she did not know why—that it must be ‘Sir Charles Faraday.’

 

Faraday did, as you know, accompany Davy to Rome: he was re-engaged by the managers of the Royal Institution on May 15, 1815. Here he made rapid progress in chemistry, and after a time was entrusted with easy analyses by Davy. In those days the Royal Institution published ‘The Quarterly Journal of Science,’ the precursor of our own ‘Proceedings.’ Faraday’s first contribution to science appeared in that journal in 1816. It was an analysis of some caustic lime from Tuscany, which had been sent to Davy by the Duchess of Montrose.

Between this period and 1818 various notes and short papers were published by Faraday. In 1818 he experimented upon ‘Sounding Flames.’ Professor Auguste De la Rive had investigated those sounding flames, and had applied to them an explanation which completely accounted for a class of sounds discovered by himself, but did not account for those known to his predecessors. By a few simple and conclusive experiments, Faraday proved the explanation insufficient. It is an epoch in the life of a young man when he finds himself correcting a person of eminence, and in Faraday’s case, where its effect was to develop a modest self-trust, such an event could not fail to act profitably.

 

From time to time between 1818 and 1820 Faraday published scientific notes and notices of minor weight. At this time he was acquiring, not producing; working hard for his master and storing and strengthening his own mind. He assisted Mr. Brande in his lectures, and so quietly, skilfully, and modestly was his work done, that Mr. Brande’s vocation at the time was pronounced ‘lecturing on velvet.’

In 1820 Faraday published a chemical paper ‘on two new compounds of chlorine and carbon, and on a new compound of iodine, carbon, and hydrogen.’ This paper was read before the Royal Society on December 21, 1820, and it was the first of his that was honoured with a place in the ‘Philosophical Transactions.’

 

On June 12, 1821, he married, and obtained leave to bring his young wife into his rooms at the Royal Institution. There for forty-six years they lived together, occupying the suite of apartments which had been previously in the successive occupancy of Young, Davy, and Brande. At the time of her marriage Mrs. Faraday was twenty-one years of age, he being nearly thirty. Regarding this marriage I will at present limit myself to quoting an entry written in Faraday’s own hand in his book of diplomas, which caught my eye while in his company some years ago. It ran thus:—

 

‘25th January, 1847.

‘Amongst these records and events, I here insert the date of one which, as a source of honour and happiness, far exceeds all the rest. We were married on June 12, 1821.

 

‘M. Faraday.’

 

Then follows the copy of the minutes, dated May 21, 1821, which gave him additional rooms, and thus enabled him to bring his wife to the Royal Institution. A feature of Faraday’s character which I have often noticed makes itself apparent in this entry. In his relations to his wife he added chivalry to affection.

 

Footnotes to Chapter 1

 

[1] Here is Davy’s recommendation of Faraday, presented to the managers of the Royal Institution, at a meeting on the 18th of March, 1813, Charles Hatchett, Esq., in the chair:—

 

‘Sir Humphry Davy has the honour to inform the managers that he has found a person who is desirous to occupy the situation in the Institution lately filled by William Payne. His name is Michael Faraday. He is a youth of twenty-two years of age. As far as Sir H.

Davy has been able to observe or ascertain, he appears well fitted for the situation. His habits seem good; his disposition active and cheerful, and his manner intelligent. He is willing to engage himself on the same terms as given to Mr. Payne at the time of quitting the Institution.

 

‘Resolved,—That Michael Faraday be engaged to fill the situation lately occupied by Mr. Payne, on the same terms.’

 

[2] Faraday loved this word and employed it to the last; he had an intense dislike to the modern term physicist.

 

[3] To whom I am indebted for a copy of the original letter.

 

Chapter 2.

 

Early researches: magnetic rotations: liquefaction of gases: heavy glass: Charles Anderson: contributions to physics.

 

Oersted, in 1820, discovered the action of a voltaic current on a magnetic needle; and immediately afterwards the splendid intellect of Ampere succeeded in showing that every magnetic phenomenon then known might be reduced to the mutual action of electric currents.

The subject occupied all men’s thoughts: and in this country Dr. Wollaston sought to convert the deflection of the needle by the current into a permanent rotation of the needle round the current.

He also hoped to produce the reciprocal effect of causing a current to rotate round a magnet. In the early part of 1821, Wollaston attempted to realise this idea in the presence of Sir Humphry Davy in the laboratory of the Royal Institution.[1] This was well calculated to attract Faraday’s attention to the subject. He read much about it; and in the months of July, August, and September he wrote a ‘history of the progress of electro-magnetism,’ which he published in Thomson’s ‘Annals of Philosophy.’ Soon afterwards he took up the subject of ‘Magnetic Rotations,’ and on the morning of Christmas-day, 1821, he called his wife to witness, for the first time, the revolution of a magnetic needle round an electric current.

Incidental to the ‘historic sketch,’ he repeated almost all the experiments there referred to; and these, added to his own subsequent work, made him practical master of all that was then known regarding the voltaic current. In 1821, he also touched upon a subject which subsequently received his closer attention—the vaporization of mercury at common temperatures; and immediately afterwards conducted, in company with Mr. Stodart, experiments on the alloys of steel. He was accustomed in after years to present to his friends razors formed from one of the alloys then discovered.

 

During Faraday’s hours of liberty from other duties, he took up subjects of inquiry for himself; and in the spring of 1823, thus self-prompted, he began the examination of a substance which had long been regarded as the chemical element chlorine, in a solid form, but which Sir Humphry Davy, in 1810, had proved to be a hydrate of chlorine, that is, a compound of chlorine and water.

Faraday first analysed this hydrate, and wrote out an account of its composition. This account was looked over by Davy, who suggested the heating of the hydrate under pressure in a sealed glass tube.

This was done. The hydrate fused at a blood-heat, the tube became filled with a yellow atmosphere, and was afterwards found to contain two liquid substances. Dr. Paris happened to enter the laboratory while Faraday was at work. Seeing the oily liquid in his tube, he rallied the young chemist for his carelessness in employing soiled vessels. On filing off the end of the tube, its contents exploded and the oily matter vanished. Early next morning, Dr. Paris received the following note:—

 

‘Dear Sir,—The oil you noticed yesterday turns out to be liquid chlorine.

 

‘Yours faithfully,

‘M. Faraday.’[2]

 

The gas had been liquefied by its own pressure. Faraday then tried compression with a syringe, and succeeded thus in liquefying the gas.

 

To the published account of this experiment Davy added the following note:—‘In desiring Mr. Faraday to expose the hydrate of chlorine in a closed glass tube, it occurred to me that one of three things would happen: that decomposition of water would occur;… or that the chlorine would separate in a fluid state.’ Davy, moreover, immediately applied the method of self-compressing atmosphere to the liquefaction of muriatic gas. Faraday continued the experiments, and succeeded in reducing a number of gases till then deemed permanent to the liquid condition. In 1844 he returned to the subject, and considerably expanded its limits. These important investigations established the fact that gases are but the vapours of liquids possessing a very low boiling-point, and gave a sure basis to our views of molecular aggregation. The account of the first investigation was read before the Royal Society on April 10, 1823, and was published, in Faraday’s name, in the ‘Philosophical Transactions.’

The second memoir was sent to the Royal Society on December 19, 1844.

I may add that while he was conducting his first experiments on the liquefaction of gases, thirteen pieces of glass were on one occasion driven by an explosion into Faraday’s eye.

 

Some small notices and papers, including the observation that glass readily changes colour in sunlight, follow here. In 1825 and 1826

Faraday published papers in the ‘Philosophical Transactions’ on ‘new compounds of carbon and hydrogen,’ and on ‘sulphonaphthalic acid.’

In the former of these papers he announced the discovery of Benzol, which, in the hands of modern chemists, has become the foundation of our splendid aniline dyes. But he swerved incessantly from chemistry into physics; and in 1826 we find him engaged in investigating the limits of vaporization, and showing, by exceedingly strong and apparently conclusive arguments, that even in the case of mercury such a limit exists; much more he conceived it to be certain that our atmosphere does not contain the vapour of the fixed constituents of the earth’s crust. This question, I may say, is