John Tyndall

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This article is about the 19th century Irish scientist. For the 20th century British politician of the same name, see John Tyndall (politician).
John Tyndall
John Tyndall.
John Tyndall.
Born August 2, 1820
Leighlinbridge, County Carlow, Ireland
Died December 4, 1893
Surrey, England
Nationality British
Fields Natural sciences
Institutions Royal Institution
Known for Publication and education
Tyndall effect

John Tyndall FRS (August 2, 1820 – December 4, 1893) was a prominent 19th century Irish physicist. His initial scientific fame arose in the 1850s from his study of diamagnetism, which led to his appointment as successor to Michael Faraday at the Royal Institution in 1862.

Contents

[edit] Life

Tyndall was born in Leighlinbridge, County Carlow, Ireland. His father was a member of the local police force and a small landowner, descended from a Tyndall who settled in Ireland, in the mid-seventeenth century, from England.

He passed from a national school in County Carlow, to take up the post of draughtsman (1839) in the Irish Ordnance Survey and then to the English Ordnance Survey (1842), attending Mechanics' Institute lectures at Preston. In 1844 he became a railway engineer, and in 1847 a teacher at Queenwood College, Hampshire. From there he and his colleague Edward Frankland, and the mathematician Thomas Hirst, attended the University of Marburg (1848-1851). All three men became mambers of the X-Club later in life. Tyndall obtained his PhD in two years under the famous Professor Robert Bunsen. Tyndall's inaugural dissertation was an essay on screw-surfaces.

In 1876 Tyndall married Louisa, daughter of Lord Claud Hamilton. He built in 1877 a cottage on Bel Alp above the Rhone valley, and in 1885 a house on Hindhead, near Haslemere in Surrey. At the latter place he spent most of his later years; his health was, however, no longer as vigorous as his brain, and he suffered frequently from sleeplessness.

In Hindhead on December 4, 1893, Louisa accidentally gave him an overdose of chloral hydrate - a drug which he took for his insomnia. His last words were, reputedly, "Louisa, you have killed your beloved John." He died during Louisa's agonizing search for an antidote. The doctor she called gave him an emetic but it failed to rouse him. [Eve & Creasey, Life and work of John Tyndall].

Louisa spent the rest of her days championing his life and work among his peers and the general public, especially children, who he had always striven to imbue with a love of science. She found it difficult to write his biography and was often at loggerheads with the biographers. She first chose the experienced Leonard Huxley, and later Eve and Creasey. She would not allow them to examine some of his private papers, for reasons which are not known. Before her death she excised pages from her own diaries relating to her personal relationship with John. These diaries, along with John Tyndall's archive, are now housed in the Royal Institution – of which he was a former Director – in London's Albermarle Street. One of their prized possessions is a sealed test-tube containing his urine. He once used his urine, in open test tubes, while studying the effect of atmospheric pollution and putrefaction. He would hang one tube on a line in London, one in Hindhead and another in his Alpine retreat, with assistants noting the extent of putrifaction. These experiments helped him prove the germ theories of his antecedents and contemporaries.

[edit] Meeting Huxley and early work

Tyndall's first original work in physical science was in his experiments on magnetism and diamagnetic polarity, on which he worked from 1850 to 1855. While he was still lecturing on natural philosophy at Queenwood College, his magnetic investigations made him known among the leading scientists of the day and, through the initiative of Sir Edward Sabine, treasurer of the Royal Society, he was elected F.R.S. in June 1852. In 1850 he had made Michael Faraday's acquaintance and, shortly before the Ipswich meeting of the British Association in 1851 he began a lasting friendship with Thomas Huxley.

The two young men stood for chairs of physics and natural history respectively, first at Toronto, next at Sydney, but they were in each case unsuccessful. On February 11, 1853 however, Tyndall gave, by invitation, a Friday-evening lecture (on "The Influence of Material Aggregation upon the Manifestations of Force") at the Royal Institution, and his public reputation was at once established. He then joined Huxley in the science section of the Westminster Review with a remit to cover the physical sciences.[1]

In May 1854 Tyndall was appointed Professor of Natural Philosophy at the Royal Institution, a post that exactly suited his striking gifts. He succeeded Faraday as scientific adviser to Trinity House and the Board of Trade in 1866, and in 1867 as Superintendent of the Royal Institution. His reverent attachment to Faraday is recorded in his memorial volume called Faraday as a Discoverer (1868).

[edit] Scientific influence

Though perhaps initially wishing to understand how electromagnetism is able to act at a distance through the air, in the 1860s and 1870s Tyndall mostly studied air, and the earth's atmosphere, and he produced a number of major scientific clarifications or discoveries about processes in the atmosphere:

  • Tyndall explained atmospheric heat in terms of the capacities of various gases to absorb or transmit radiant heat. He constructed the first ratio spectrophotometer which he used to measure the absorptive powers of the gases nitrogen, oxygen, water vapour, carbon dioxide, ozone, hydrocarbons, etc. He concluded that water vapour is the strongest absorber of heat in the atmosphere and is the principal gas controlling air temperature.
  • He scientifically characterized the scattering of light by dust and large molecules in the air, now known as the Tyndall Effect. In studying the interactions between light and the constituents of air, he developed the nephelometer and other precision instruments.
  • In the lab he developed 'optically pure' (i.e. extremely filtered) air. This air contained relatively very little or no micro-organisms. He compared what happened when he let prepared meat sit in such pure air and in ordinary air. The preparations in the pure air didn't go putrid, unlike the ones in ordinary air. These studies extended Louis Pasteur's recent demonstrations about germs. But Tyndall was also able to discover germ spores in even the most carefully cleaned and filtered air, which, at the time, had the effect of counter-refuting some would-be refutations of Pasteur's "germ theory"; and he devised a method of killing the spores that came to be known as "tyndallization".
  • He is credited with the first ever atmospheric pollution measurements using infrared and scattering measurement instruments to monitor a city's air quality (in London).
  • He was the first to show that ozone is an oxygen cluster (it was thought to have been a hydrogen compound).
  • During the 1860s and 1870s he published a number of research reports about sound propagation in air, and he invented a better foghorn based on his knowledge in this area.
  • Invented a fireman's respirator, a hood that filtered smoke and gas from air.

Following tangentially from his study of the interaction between light and the constituents of air, Tyndall developed a practical demonstration of the propagation of light though a flexible tube of water via total internal reflection. This he referred to as the light-pipe. It is historically significant today because it is the first recorded demonstration of the scientific foundation for modern fiber optic technology. He demonstrated it to members of the Royal Society in 1870.

Besides a scientist, John Tyndall was an evangelist for the cause of science – he spent a significant amount of his time promoting science to the general public. Tyndall contributed over the years to science columns in a number of popular middle class periodicals. He often gave public lectures to non-specialist audiences. When he went on a public lecture tour in USA in 1872, large crowds paid fees to hear him. His greatest audience was gained ultimately thorough his books and he published more than 16 books plus 145 papers in his lifetime.[2]

[edit] Glaciology

John Tyndall explored the glacial tributaries feeding Mer de Glace in 1857, at times accompanied by Huxley
John Tyndall explored the glacial tributaries feeding Mer de Glace in 1857, at times accompanied by Huxley

Tyndall made an extended and serious investigation of glacier motion, developing a close association with Switzerland and a prolonged controversy with other contemporary scientists.

In 1854, after the meeting of the British Association in Liverpool, Tyndall took part in a memorable visit to the Penrhyn slate quarries, where the question of "slaty cleavage" arose in his mind, and ultimately led him, with Huxley, to Switzerland to study the phenomena of glaciers of the Alps. Here the mountains seized him, and he became a constant visitor and one of the most intrepid and most resolute of mountaineers and explorers. Among other feats of climbing, he was the first to ascend the Weisshorn (1861). Tyndall climbed to within a few hundred feet of the top of the Matterhorn in 1864, the year before Edward Whymper succeeded. He would have made the summit but, when at the Matterhorn's penultimate peak, he grudgingly took the advice of his guide to turn back as a storm loomed. The penultimate peak is named in his honour – 'John Tyndall 1864' is engraved on a stone upon it. The strong, vigorous, healthiness and enjoyment that permeate the record of his Alpine work are magnificent, and other traces of his influence remain in Switzerland to this day.

His mountaineering expeditions became legendary with his fellows in London's prestigious Alpine Club, which he joined in 1858[citation needed] - after one breakfast he summitted Monte Rosa solo carrying only a ham sandwich for sustenance.[3]

The problem of the flow of glaciers occupied his attention for years, and his views brought him into acute conflict with others, particularly James David Forbes and James Thomson. Every-one knew that glaciers moved, but the questions were: how they moved, for what reason and by what mechanism. Some thought they slid like solids, others that they flowed like liquids, others that they crawled by alternate expansion and contraction, or by alternate freezing and melting. Others again thought that they broke and mended. Thus there arose a chaos of controversy, illuminated by definite measurements and observations. Tyndall's own summary of the course of research on the subject was as follows:

The idea of semi-fluid motion belongs entirely to Rendu; the proof of the quicker central flow belongs in part to Rendu, but almost wholly to Agassiz and Forbes; the proof of the retardation of the bed belongs to Forbes alone; while the discovery of the locus of the point of maximum motion belongs, I suppose, to me.

But while Forbes asserted that ice was viscous, Tyndall denied it,[4] and insisted, as the result of his observations, on the flow being due to fracture and regelation.[5] All agreed that ice flowed as if it were a viscous fluid and James Thomson offered an independent and purely thermodynamic explanation of this apparent viscosity. Tyndall considered Thomson's explanation insufficient to account for the facts he observed but Hermann Helmholtz, in his lecture on "Ice and Glaciers," adopted Thomson's theory, and afterwards added in an appendix that he had come to the conclusion that Tyndall had "assigned the essential and principal cause of glacier motion in referring it to fracture and regelation" (1865).

[edit] Thermodynamics and microbiology

Tyndall's investigations of the transparency and opacity of gases and vapours for radiant heat, which occupied him during many years (1859-1871), are frequently considered his chief scientific work. But his activities were essentially many-sided. He definitely established the absorptive power of clear aqueous vapour – a point of great meteorological significance. An accomplished mountaineer fascinated with Louis Agassiz's daring proposal of ice ages, in which glaciers once covered enormous parts of the globe, Tyndall's experiments showed that in addition to water vapour, carbonic acid (H2CO3) – the form of carbon dioxide dissolved in water – can absorb a great deal of heat energy.[1] He then linked this phenomenon to the possibility of changes in the climate, trying to explain why glaciers could advance and retreat.[6] He made brilliant experiments elucidating the blue of the sky (which is a phenomenon resulting from Rayleigh scattering of sunlight) and discovered the precipitation of organic vapours by means of light. He called attention to curious phenomena occurring in the track of a luminous beam. He examined the opacity of the air for sound in connection with lighthouse and siren work.

Tyndall finally clinched the proof of what already had been substantially demonstrated by several others (particularly Louis Pasteur) that germ-free air did not initiate putrefaction, and that accordingly "spontaneous generation" was a chimera (1875–1876). A practical outcome of this research was a method of sterilizing a liquid medium by heating it to the boiling point at atmospheric pressure on successive days ("Tyndallization"). This treatment is sufficient to kill the growing microorganisms that develop from heat-refractory spores after the first day. "Tyndallization" is useful for sterilization of growth media for high school science classes and in other situations where autoclaves are unavailable for pressure sterilization.[2]

For the substantial publication of these researches reference must be made to the Transactions of the Royal Society; but an account of many of them was incorporated in his best-known books, namely, the famous Heat as a Mode of Motion (1863; and later editions to 1880), the first popular exposition of the mechanical theory of heat, which in 1862 had not reached the textbooks; The Forms of Water, &c. (1872); Lectures on Light (1873); Essays on the floating-matter of the air in relation to putrefaction and infection (1881); On Sound (1867; revised 1875, 1883, 1803). The original memoirs themselves on radiant heat and on magnetism were collected and issued as two large volumes under the following titles: Diamagnetism and Magne-crystallic action (1870); Contributions to Molecular Physics in the domain of radiant heat (1872). In 1875 Tyndall reported to the Royal Society in London that a species of Penicillium had caused some of his bacteria to burst. This discovery of antibiotic properties of Penicillium predated Ernest Duchesne by 20 years and Alexander Fleming by over 50 years.

[edit] Personality and private life

John Tyndall
John Tyndall

It was on the whole the personality, rather than the discoverer, that was most prominent in Tyndall. In the pursuit of science for its own sake he shone as a beacon to younger men — an example of simple tastes, robust nature and lofty aspirations. His elevation above the common run of men was seen in his treatment of the money which came to him by his successful lecturing tour in the United States (1872–1873). It amounted to several thousand pounds, but he would touch none of it; he placed it in the hands of trustees for the benefit of American science — a gift which showed a noble nature.

Though not so prominent as Huxley in detailed controversy over theological problems, Tyndall played an important part in educating the public mind in the attitude which the development of natural philosophy entailed towards dogma and religious authority. His famous Belfast address (1874), as President of the British Association, gave an account of the history of evolutionary theories, and made a great stir among those who were then busy with the supposed conflict between science and religion. In his occasional writings — Fragments of Science, as he called them, "for unscientific people" — he attempted to dissuade people from current conceptions of prayer, miracles, etc., with characteristic straightforwardness and vigour.

Tyndall became financially quite well-off. Not only was the income from his lecture tour in the US donated to science, but he donated money to establish a new technical school in County Carlow in Ireland. Like the great majority of Irish-born scientists of the 19th century Tyndall was an opponent of Home Rule for Ireland. He tried unsuccessfully to get the Royal Society to denounce the Home Rule proposal as bad for science.[7] It is said (though it may be allegorical) that Tyndall is the originator of the slogan "Home Rule would be Rome Rule".[8]

He was also a pioneering mountain climber and a member of the London-based Alpine Club. He climbed variously in his beloved Alps, including Mont Blanc several times, was the first to climb the Weisshorn and almost beat the conqueror of the Matterhorn, Edward Whymper, to the notorious mountain's summit. When he was just beyond the penultimate peak and in reach of his goal, a storm blew up and his guide insisted on going back down. The penultimate peak is named "Pic Tyndall" in his honour.

[edit] Honours

  • A crater on Mars is named in his honour, as is a pub in Carlow town, a mountain, Mount Tyndall, in California's Sierra Nevada range and the penultimate peak of the Matterhorn in the Alps.
  • The asteroid 22694 Tyndall was named in his honour on 1 June 2007.†
  • In 2005 the NMRC in Ireland joined with the Photonics group of UCC, to form The Tyndall National Institute in Cork, Ireland, named in his honour. (see link below)

[edit] See also

[edit] Bibliography

[edit] Footnotes

  1. ^ Desmond, Adrian 1994. Huxley: vol 1 The Devil's Disciple. Joseph, London. p205, and Huxley Papers at Imperial College, THH to JT, HP9.12.
  2. ^ Biography of John Tyndall at The Tyndall Centre for Climate Change Research.
  3. ^ John Tyndall [1860] 1896. The Glaciers of the Alps. Longmans, London. Republished as Tyndall J. [1860] 2005. The Glaciers of the Alps. Adamant Media Corp. p151-157: Tyndall had already summitted Mont Blanc in a group in 1857, and Monte Rosa in a guided group on 1858-08-10 (p122-129), but he made an unplanned second summit solo on 1858-08-17 after breakfast: "the waiter then provided me with a ham sandwich, and, with my scrip thus frugally furnished, I thought the heights of Monte Rosa might be won." Between the two ascents Tindall had further investigated the magnetic anomalies on Riffelhorn reported earlier by Professor Forbes. p143
  4. ^ John Tyndall 1896. The Glaciers of the Alps. Longmans, London. p307-314
  5. ^ John Tyndall 1896. The Glaciers of the Alps. Longmans, London. p422-6
  6. ^ A Short Biography of John Tyndall. Tyndall Centre for Climate Change Research.
  7. ^ Jones, Greta (2001), “Scientists against home rule”, in Boyce, D. George & O'Day, Alan, Defenders of the Union: A Survey of British and Irish Unionism Since 1801, London: Routledge, pp. 188 – 208 .
  8. ^ John Tyndall. Princess Grace Irish Library (Monaco).

[edit] Biographies of Tyndall

  • Burchfield, J.A. (1981). John Tyndall, Essays on a Natural Philosopher. Dublin: Royal Dublin Society. 
  • Eve, A.S & Creasey, C.H. (1945). Life and Work of John Tyndall. London: Macmillan. 
  • McMillan N.D. and Meehan J. John Tyndall: 'X'emplar of scientific & technological education. National Council for Educational Awards, Dublin [1980]. [despite its chaotic organisation, this little book contains some nuggets that are well worth sifting]

[edit] External links

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