DOCSLIB.ORG

The Early History of Radioactivity (1896-1904) Thesis Presented For

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

The Early History of Radioactivity (1896-1904) Thesis presented for the degree of Doctor of Philosophy in the Field of History of Science by Stephen Brian Sinclair Department of History of Science and Technology Imperial College of Science and Technology University of London May 1976 2 ABSTRACT Both the beginning and end of this history are ostensibly well defined. Becquerel's quiet discovery of uranium rays came to fruition in the appearance of the first standard textbooks on radioactivity, with their claims for an independent subject area. One may see in the intervening period the progressive construction of a new bridge between physics and chemistry founded on a coherent theory of atomic transmutation and disintegration. My examination of the scene from the viewpoints of several interested parties reveals an alternative picture comprising complex linked series of discoveries, experiments and hypotheses of various levels. At the moving boundaries of research the results and conclusions of individuals were always subject to reinterpretation in their adoption by others. This study thus proceeds in the light of three main considerations. These are, firstly, parallel investigations in radioactivity by different workers; secondly, contemporary related areas of physical science such as X-rays, cathode rays, corpuscular theory; and thirdly, the relevant concepts developed earlier, during the nineteenth century. The introductory chapter concentrates upon the last of these, considering some long-standing hopes and unanswered questions concerning, for example, the unification of matter, ether, and electricity, and the relations between the chemical elements. This forms an essential part of the background to radioactivity. Chapter two describes the opening of the radiochemical field by the Curies, following Becquerel's original discovery, and discusses the blending of these results with Rutherford's earliest radiation studies. The third chapter deals with a confused phase where new observations 3 outran theory as 'emanations', 'induced' activities, spontaneous cathode-ray emissions, and dubious radiochemical claims combined with the ever-growing energy problem. The fourth and fifth chapters trace the emergence of rival theories, and the singular success of one of these at the expense of all others. 4 ACKNOWLEDGMENTS I wish to thank for their assistance those who made manuscript materials available to me at the following institutions: Cambridge University Library, Bibliotheque Nationale, Academie des Sciences, Royal Institution of Great Britain, Wellcome Institute for the History of Medicine Library, Library of University College London, Library of the Royal Society, Bodleian Library, Science Museum Library, Imperial College Archives. To my research supervisor Dr. M.B. Hall of the Department of History of Science and Technology, Imperial College, I am greatly indebted for her patient advice throughout the project and for her careful reading of this thesis during its construction. TABLE OF CONTENTS ABSTRACT 2 ACKNOWLEDGEMENTS 4 CHAPTER 1. NINETEENTH-CENTURY THREADS 8 1. Introduction 8 Scientific revolution - summary of threads. 2. Chemical atomic theories and the unity and complex ty of the chemical elements 12 Dalton's theory - evolution and compound nature of elements - Crookes - Stokes - Lockyer - J.J.Thomson. 3. Physical theories of matter, electricity, ether 24 Maxwell - various ethers - Larmor - Lorentz - Zeeman - Mme.Curie, Rutherford - Hertzian molecule. 4. Chemical physics. Physical chemistry 32 Hertzian atom - Stoney's electron theory - electrochemistry - vortex atom - J.J.Thomson - electricity and gases - corpuscular atom. CHAPTER 2. THE DISCOVERY OF URANIUM RAYS AND RADIOACTIVITY 48 1. Becquerel's discovery of uranium rays (1896-7) 48 X-rays and phosphorescence.- Becquerel and uranium rays - nature of the rays - S.P.Thompson - other radiations - vapours and W.J.Russell's photographic work - electrical studies. 2. Rutherford, and the Cavendish Laboratory (1894-8) 70 Hertzian radiation and magnetism - X-rays and conductivity of gases - ionic theory - ultraviolet radiation - uranium rays. 3. Pierre Curie, Marie Curie and the new radioactive elements (1890.17)-- 92 P.Curie's researches - Marie Curie - thorium rays - G.C.Schmidt - polonium - radium - atomic property - energy source, speculations. 4. Theories and trends (1896-9) 110 Source of the energy - interest in uranium rays - development of theories - atomic change. 6 CHAPTER 3. EMANATIONS AND RADIATIONS 119 1. The ma netic deflection of the Becquerel rays 1 9-1900) 119 The rays from active substances and their magnetic deflection - magnetism and radio- activity - Becquerel's 'material rays'. 2. The discovery of induced radioactivity (1899) 129 The Curies' discovery, 'la radioactivite induite' - Rutherford's idea of a thorium emanation - properties of the emanation - the production of a radioactive deposit. 3. The source of radioactivity (1900) 147 The effect of temperature change and its implications - phosphorescence, Behrendsen, and the views of Becquerel - Marie Curie's speculations on atomic change and disintegration - Rutherford and the energy of radioactivity. 4. Emanations and the X-substances (1900-1) 162 Fitzgerald, and transmutations - A.Debierne and actinium - induced radioactivity: Giesel, Hofmann, and radiolead; P.Villard - Crookes and UrX - the Curies' views - E.Dorn and an emanation from radium - Rutherford's problems with the emanations - atmospheric emanation of Elster and Geitel. CHAPTER 4. DISINTEGRATION, INDUCTION, TRANSFORMATION 179 1. The emergence of induction and disintegration gorfes (1901-1.) 179 Ionic and emanation hypotheses of Elster and Geitel - comparison of theories - induced radioactivity; the function of the gaseous medium - radioactive water; the induction theory of Curie and Debierne - Becquerel, uranium and auto-induction - Curies' criticism - Crookes and ultra-atomic diffusion - Martin and total disintegration - J.Stark and the genesis of atoms . 2. A quantitative theory of atomic transmutation T1902) 196 Introduction - F.Soddy - the first joint publication: an inert gas from thorium, a possible transmutation; ThX as the source of the emanation - Rutherford and the transmission of excited radioactivity - interpretations of Becquerel's views - the second publication: thorium and ThX, transmutation quantitatively observed - the new accompaniment version of the disintegration theory, and the question of induction. 7 CHAPTER 5. RECEPTIONS, GENERALISATIONS, SPECULATIONS 226 1. Reception of the disintegration theory (1902-3) 226 Introduction - changing views of the Caries; the heat from radium - F.Giesel - J.J.Thomson: wind, water, and atomic disintegration - Crookes and the mysteries of radium; a wider public - creation of helium; the Curies converted - the summit of fame - physicists and chemists: a campaign well fought. 2. The mechanism of radioactivity (1903-4) 252 Speculations of physical chemists: ether, energy, electrons - Soddy and the randomness of disintegration - physical models for radioactivity - Lodge's radiation-loss hypothesis - Kelvin's atomic theories - Nagaoka's saturnian atom - Thomson's corpuscular atom. 3. Conclusion 271 Rutherford and the succession of changes - cosmical, universal, and Proutian radioactivity. NOTES FOR CHAPTERS 1 to 5 281 BIBLIOGRAPHY 331 Ri3 RE .f% 14-nonis 361e 8 CHAPTER 1 NINETEENTH-CENTURY THREADS 1. Introduction The discovery of X-rays by ROntgen in 1895, which led directly to Becquerel's discovery of uranium rays, has been hailed as marking a watershed in physics, the beginning of a revolution. This interpretation generally invokes the further statement that from 1880 to the turn of the century physical science had attained a satisfactory state with few internal problems.'The latter idea, with its implication of some form of stagnation in research, seems the more dubious of the two. The words of Maxwell's 'Introductory Lecture on Experimental Physics' of 1871 have been used to support this view: the opinion seems to have got abroad, that in a few years all the great physical constants will have been approximately estimated, and that the only occupation which will then be left to men of science will be to carry on these measurements to another place of decimals.2 That this was not 'really the state of things to which we are approaching' is shown by his own continuation: But we have no right to think thus of the unsearchable riches of creation, or of the untried fertility of those fresh minds into which these riches will continue to be poured...3 And although the great chemist Marcelin Berthelot in introducing his book, Les Origines de L'Alchimie, of 1885, wrote that the worm was then 'without mystery',4 scientists in other areas took quite the opposite view. Oliver Lodge concluding his book Modern Views of Electricity, of 1889,. wrote: 'Conclusion' is an absurd word to write at the present time, when the whole subject is astir with life, and when every month seems to bring out some fresh aspect...5 And we will leave Lodge with a resounding word on this particular point, in his lecture on 'The Discharge of a 9 Leyden Jar' at the Royal Institution, in the same year; The present is an epoch of astounding activity in physical science. Progress is a thing of months and weeks, almost of days. The long line of isolated ripples of past discovery seem blending into a mighty wave, on the crest of which one begins to discern some oncoming magnificent generalisation. The suspense is becoming feverish,
Recommended publications
  • Unerring in Her Scientific Enquiry and Not Afraid of Hard Work, Marie Curie Set a Shining Example for Generations of Scientists

    Unerring in Her Scientific Enquiry and Not Afraid of Hard Work, Marie Curie Set a Shining Example for Generations of Scientists

    Historical profile Elements of inspiration Unerring in her scientific enquiry and not afraid of hard work, Marie Curie set a shining example for generations of scientists. Bill Griffiths explores the life of a chemical heroine SCIENCE SOURCE / SCIENCE PHOTO LIBRARY LIBRARY PHOTO SCIENCE / SOURCE SCIENCE 42 | Chemistry World | January 2011 www.chemistryworld.org On 10 December 1911, Marie Curie only elements then known to or ammonia, having a water- In short was awarded the Nobel prize exhibit radioactivity. Her samples insoluble carbonate akin to BaCO3 in chemistry for ‘services to the were placed on a condenser plate It is 100 years since and a chloride slightly less soluble advancement of chemistry by the charged to 100 Volts and attached Marie Curie became the than BaCl2 which acted as a carrier discovery of the elements radium to one of Pierre’s electrometers, and first person ever to win for it. This they named radium, and polonium’. She was the first thereby she measured quantitatively two Nobel prizes publishing their results on Boxing female recipient of any Nobel prize their radioactivity. She found the Marie and her husband day 1898;2 French spectroscopist and the first person ever to be minerals pitchblende (UO2) and Pierre pioneered the Eugène-Anatole Demarçay found awarded two (she, Pierre Curie and chalcolite (Cu(UO2)2(PO4)2.12H2O) study of radiactivity a new atomic spectral line from Henri Becquerel had shared the to be more radioactive than pure and discovered two new the element, helping to confirm 1903 physics prize for their work on uranium, so reasoned that they must elements, radium and its status.
  • Introduction 1

    Introduction 1

    1 1 Introduction . ex arte calcinati, et illuminato aeri [ . properly calcinated, and illuminated seu solis radiis, seu fl ammae either by sunlight or fl ames, they conceive fulgoribus expositi, lucem inde sine light from themselves without heat; . ] calore concipiunt in sese; . Licetus, 1640 (about the Bologna stone) 1.1 What Is Luminescence? The word luminescence, which comes from the Latin (lumen = light) was fi rst introduced as luminescenz by the physicist and science historian Eilhardt Wiede- mann in 1888, to describe “ all those phenomena of light which are not solely conditioned by the rise in temperature,” as opposed to incandescence. Lumines- cence is often considered as cold light whereas incandescence is hot light. Luminescence is more precisely defi ned as follows: spontaneous emission of radia- tion from an electronically excited species or from a vibrationally excited species not in thermal equilibrium with its environment. 1) The various types of lumines- cence are classifi ed according to the mode of excitation (see Table 1.1 ). Luminescent compounds can be of very different kinds: • Organic compounds : aromatic hydrocarbons (naphthalene, anthracene, phenan- threne, pyrene, perylene, porphyrins, phtalocyanins, etc.) and derivatives, dyes (fl uorescein, rhodamines, coumarins, oxazines), polyenes, diphenylpolyenes, some amino acids (tryptophan, tyrosine, phenylalanine), etc. + 3 + 3 + • Inorganic compounds : uranyl ion (UO 2 ), lanthanide ions (e.g., Eu , Tb ), doped glasses (e.g., with Nd, Mn, Ce, Sn, Cu, Ag), crystals (ZnS, CdS, ZnSe, CdSe, 3 + GaS, GaP, Al 2 O3 /Cr (ruby)), semiconductor nanocrystals (e.g., CdSe), metal clusters, carbon nanotubes and some fullerenes, etc. 1) Braslavsky , S. et al . ( 2007 ) Glossary of terms used in photochemistry , Pure Appl.
  • The Riches of Uranium Uranium Is Best Known, and Feared, for Its Involvement in Nuclear Energy

    The Riches of Uranium Uranium Is Best Known, and Feared, for Its Involvement in Nuclear Energy

    in your element The riches of uranium Uranium is best known, and feared, for its involvement in nuclear energy. Marisa J. Monreal and Paula L. Diaconescu take a look at how its unique combination of properties is now increasingly attracting the attention of chemists. t is nearly impossible to find an uplifting, and can be arrested by the skin, making found about uranium’s superior catalytic funny, or otherwise endearing quote on depleted uranium (composed mainly of 238U) activity may not be an isolated event. The Iuranium — the following dark wisecrack1 safe to work with as long as it is not inhaled organometallic chemistry of uranium was reflects people’s sinister feelings about this or ingested. born during the ‘Manhattan project’ — code element: “For years uranium cost only a few Studying the fundamental chemistry of name of the development of the first nuclear dollars a ton until scientists discovered you uranium is an exotic endeavour, but those who weapon during the Second World War. This could kill people with it”. But, in the spirit of embrace it will reap its benefits. Haber and field truly began to attract interest in 1956 rebranding, it is interesting to note that the Bosch found that uranium was a better catalyst when Reynolds and Wilkinson reported the main source of Earth’s internal heat comes than iron for making ammonia2. The preparation of the first cyclopentadienyl from the radioactive decay of uranium, isolation of an η1-OCO complex derivatives6. The discovery of thorium and potassium-40 that keeps the of uranium3 also showed uranocene electrified the field outer core liquid, induces mantle convection that, even though it is as much as that of ferrocene and, subsequently, drives plate tectonics.
  • Historical Group

    Historical Group

    Historical Group NEWSLETTER and SUMMARY OF PAPERS No. 64 Summer 2013 Registered Charity No. 207890 COMMITTEE Chairman: Prof A T Dronsfield | Prof J Betteridge (Twickenham, 4, Harpole Close, Swanwick, Derbyshire, | Middlesex) DE55 1EW | Dr N G Coley (Open University) [e-mail [email protected]] | Dr C J Cooksey (Watford, Secretary: Prof. J. W. Nicholson | Hertfordshire) School of Sport, Health and Applied Science, | Prof E Homburg (University of St Mary's University College, Waldegrave | Maastricht) Road, Twickenham, Middlesex, TW1 4SX | Prof F James (Royal Institution) [e-mail: [email protected]] | Dr D Leaback (Biolink Technology) Membership Prof W P Griffith | Dr P J T Morris (Science Museum) Secretary: Department of Chemistry, Imperial College, | Mr P N Reed (Steensbridge, South Kensington, London, SW7 2AZ | Herefordshire) [e-mail [email protected]] | Dr V Quirke (Oxford Brookes Treasurer: Dr J A Hudson | University) Graythwaite, Loweswater, Cockermouth, | Prof. H. Rzepa (Imperial College) Cumbria, CA13 0SU | Dr. A Sella (University College) [e-mail [email protected]] Newsletter Dr A Simmons Editor Epsom Lodge, La Grande Route de St Jean, St John, Jersey, JE3 4FL [e-mail [email protected]] Newsletter Dr G P Moss Production: School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS [e-mail [email protected]] http://www.chem.qmul.ac.uk/rschg/ http://www.rsc.org/membership/networking/interestgroups/historical/index.asp 1 RSC Historical Group Newsletter No. 64 Summer 2013 Contents From the Editor 2 Obituaries 3 Professor Colin Russell (1928-2013) Peter J.T.
  • Epistemology of Research on Radiation and Matter: a Structural View

    Epistemology of Research on Radiation and Matter: a Structural View

    Kairos. Journal of Philosophy & Science 22, 2019 Center for the Philosophy of Sciences of Lisbon University Epistemology of Research on Radiation and Matter: a Structural View Isabel Serra (CFCUL) ([email protected]) Elisa Maia (CFCUL e IIBRC) ([email protected]) DOI 10.2478/kjps-2019–0016 Abstract The modern understanding of radiation got its start in 1895 with X-rays discovered by Wilhelm Röntgen, followed in 1896 by Henri Becquerel’s discovery of radioactivity. The development of the study of radiation opened a vast field of resear- ch concerning various disciplines: chemistry, physics, biology, geology, sociology, ethics, etc. Additionally, new branches of knowledge were created, such as atomic and nuclear physics that enabled an in-depth knowledge of the matter. Moreover, during the historical evolution of this body of knowledge a wide variety of new te- chnologies was emerging. This article seeks to analyze the characteristics of expe- rimental research in radioactivity and microphysics, in particular the relationship experience-theory. It will also be emphasized that for more than two decades, since the discovery of radioactivity, experiments took place without the theory being able to follow experimental dynamics. Some aspects identified as structural features of scientific research in the area of radiation and matter will be addressed through his- torical examples. The inventiveness of experiments in parallel with the emergence of quantum mechanics, the formation of teams and their relationship with technology developed from the experiments, as well as the evolution of microphysics in the sen- se of “Big Science” will be the main structural characteristics here focused. The case study of research in radioactivity in Portugal that assumes a certain importance and has structural characteristics similar to those of Europe will be presented.
  • Download Report 2010-12

    Download Report 2010-12

    RESEARCH REPORt 2010—2012 MAX-PLANCK-INSTITUT FÜR WISSENSCHAFTSGESCHICHTE Max Planck Institute for the History of Science Cover: Aurora borealis paintings by William Crowder, National Geographic (1947). The International Geophysical Year (1957–8) transformed research on the aurora, one of nature’s most elusive and intensely beautiful phenomena. Aurorae became the center of interest for the big science of powerful rockets, complex satellites and large group efforts to understand the magnetic and charged particle environment of the earth. The auroral visoplot displayed here provided guidance for recording observations in a standardized form, translating the sublime aesthetics of pictorial depictions of aurorae into the mechanical aesthetics of numbers and symbols. Most of the portait photographs were taken by Skúli Sigurdsson RESEARCH REPORT 2010—2012 MAX-PLANCK-INSTITUT FÜR WISSENSCHAFTSGESCHICHTE Max Planck Institute for the History of Science Introduction The Max Planck Institute for the History of Science (MPIWG) is made up of three Departments, each administered by a Director, and several Independent Research Groups, each led for five years by an outstanding junior scholar. Since its foundation in 1994 the MPIWG has investigated fundamental questions of the history of knowl- edge from the Neolithic to the present. The focus has been on the history of the natu- ral sciences, but recent projects have also integrated the history of technology and the history of the human sciences into a more panoramic view of the history of knowl- edge. Of central interest is the emergence of basic categories of scientific thinking and practice as well as their transformation over time: examples include experiment, ob- servation, normalcy, space, evidence, biodiversity or force.
  • ARIE SKLODOWSKA CURIE Opened up the Science of Radioactivity

    ARIE SKLODOWSKA CURIE Opened up the Science of Radioactivity

    ARIE SKLODOWSKA CURIE opened up the science of radioactivity. She is best known as the discoverer of the radioactive elements polonium and radium and as the first person to win two Nobel prizes. For scientists and the public, her radium was a key to a basic change in our understanding of matter and energy. Her work not only influenced the development of fundamental science but also ushered in a new era in medical research and treatment. This file contains most of the text of the Web exhibit “Marie Curie and the Science of Radioactivity” at http://www.aip.org/history/curie/contents.htm. You must visit the Web exhibit to explore hyperlinks within the exhibit and to other exhibits. Material in this document is copyright © American Institute of Physics and Naomi Pasachoff and is based on the book Marie Curie and the Science of Radioactivity by Naomi Pasachoff, Oxford University Press, copyright © 1996 by Naomi Pasachoff. Site created 2000, revised May 2005 http://www.aip.org/history/curie/contents.htm Page 1 of 79 Table of Contents Polish Girlhood (1867-1891) 3 Nation and Family 3 The Floating University 6 The Governess 6 The Periodic Table of Elements 10 Dmitri Ivanovich Mendeleev (1834-1907) 10 Elements and Their Properties 10 Classifying the Elements 12 A Student in Paris (1891-1897) 13 Years of Study 13 Love and Marriage 15 Working Wife and Mother 18 Work and Family 20 Pierre Curie (1859-1906) 21 Radioactivity: The Unstable Nucleus and its Uses 23 Uses of Radioactivity 25 Radium and Radioactivity 26 On a New, Strongly Radio-active Substance
  • Miller's Waves

    Miller's Waves

    Miller’s Waves An Informal Scientific Biography William Fickinger Department of Physics Case Western Reserve University Copyright © 2011 by William Fickinger Library of Congress Control Number: 2011903312 ISBN: Hardcover 978-1-4568-7746-0 - 1 - Contents Preface ...........................................................................................................3 Acknowledgments ...........................................................................................4 Chapter 1-Youth ............................................................................................5 Chapter 2-Princeton ......................................................................................9 Chapter 3-His Own Comet ............................................................................12 Chapter 4-Revolutions in Physics..................................................................16 Chapter 5-Case Professor ............................................................................19 Chapter 6-Penetrating Rays ..........................................................................25 Chapter 7-The Physics of Music....................................................................31 Chapter 8-The Michelson-Morley Legacy......................................................34 Chapter 9-Paris, 1900 ...................................................................................41 Chapter 10-The Morley-Miller Experiment.....................................................46 Chapter 11-Professor and Chair ...................................................................51
  • The History of Solar

    The History of Solar

    Solar technology isn’t new. Its history spans from the 7th Century B.C. to today. We started out concentrating the sun’s heat with glass and mirrors to light fires. Today, we have everything from solar-powered buildings to solar- powered vehicles. Here you can learn more about the milestones in the Byron Stafford, historical development of solar technology, century by NREL / PIX10730 Byron Stafford, century, and year by year. You can also glimpse the future. NREL / PIX05370 This timeline lists the milestones in the historical development of solar technology from the 7th Century B.C. to the 1200s A.D. 7th Century B.C. Magnifying glass used to concentrate sun’s rays to make fire and to burn ants. 3rd Century B.C. Courtesy of Greeks and Romans use burning mirrors to light torches for religious purposes. New Vision Technologies, Inc./ Images ©2000 NVTech.com 2nd Century B.C. As early as 212 BC, the Greek scientist, Archimedes, used the reflective properties of bronze shields to focus sunlight and to set fire to wooden ships from the Roman Empire which were besieging Syracuse. (Although no proof of such a feat exists, the Greek navy recreated the experiment in 1973 and successfully set fire to a wooden boat at a distance of 50 meters.) 20 A.D. Chinese document use of burning mirrors to light torches for religious purposes. 1st to 4th Century A.D. The famous Roman bathhouses in the first to fourth centuries A.D. had large south facing windows to let in the sun’s warmth.
  • Absolute Zero, Absolute Temperature. Absolute Zero Is the Lowest

    Absolute Zero, Absolute Temperature. Absolute Zero Is the Lowest

    Contents Radioactivity: The First Puzzles................................................ 1 The “Uranic Rays” of Henri Becquerel .......................................... 1 The Discovery ............................................................... 2 Is It Really Phosphorescence? .............................................. 4 What Is the Nature of the Radiation?....................................... 5 A Limited Impact on Scientists and the Public ............................ 6 Why 1896? .................................................................. 7 Was Radioactivity Discovered by Chance? ................................ 7 Polonium and Radium............................................................. 9 Marya Skłodowska .......................................................... 9 Pierre Curie .................................................................. 10 Polonium and Radium: Pierre and Marie Curie Invent Radiochemistry.. 11 Enigmas...................................................................... 14 Emanation from Thorium ......................................................... 17 Ernest Rutherford ........................................................... 17 Rutherford Studies Radioactivity: ˛-and ˇ-Rays.......................... 18 ˇ-Rays Are Electrons ....................................................... 19 Rutherford in Montreal: The Radiation of Thorium, the Exponential Decrease........................................... 19 “Induced” and “Excited” Radioactivity .................................... 20 Elster
  • Taming the Beast

    Taming the Beast

    Inorganic Stamp Corner by Daniel Rabinovich Taming the Beast The French chemist Henri Moissan (1852-1907) was awarded the 1906 Nobel Prize in Chemistry for two rather different areas of scientific endeavor, namely the isolation of elemental fluorine and the introduction of the electric furnace in the preparation of metal carbides and other refractory materials. The selection committee of the Royal Swedish Academy of Sciences had a particularly difficult task that year, and Moissan edged out by a single vote (5-4) no one less than Dmitri Mendeleev, of periodic table fame. Unfortunately the renowned Russian chemist, who was considered an eccentric genius but an outsider in the European establishment, never got a chance to be nominated again since he died of influenza on February 2, 1907. As bad luck would have it, Moissan himself died from acute appendicitis only 18 days later, shortly after returning to Paris from his trip to Stockholm. The isolation of fluorine in 1886 was a remarkable achievement given the extreme reactivity of this element. Moissan succeeded by electrolyzing at -25 °C a solution of potassium hydrogen fluoride (KHF2) dissolved in anhydrous hydrogen fluoride, using special platinum– iridium electrodes in a platinum U-shaped vessel capped with fluorite (CaF2) stoppers. Not exactly an experiment undergraduate students conduct today in a laboratory course! In any event, Moissan’s electrolytic cell is depicted on the two French stamps shown herein. Interestingly, the stamp on the left, released in 1986 to commemorate fluorine’s centennial, displays the incorrect (reverse) chemical equation, i.e., hydrogen does react with fluorine to yield hydrogen fluoride, but that is evidently not how the lightest halogen was isolated in the first place! .
  • The Techniques and Material Aesthetics of the Daguerreotype

    The Techniques and Material Aesthetics of the Daguerreotype

    The Techniques and Material Aesthetics of the Daguerreotype Michael A. Robinson Submitted for the degree of Doctor of Philosophy Photographic History Photographic History Research Centre De Montfort University Leicester Supervisors: Dr. Kelley Wilder and Stephen Brown March 2017 Robinson: The Techniques and Material Aesthetics of the Daguerreotype For Grania Grace ii Robinson: The Techniques and Material Aesthetics of the Daguerreotype Abstract This thesis explains why daguerreotypes look the way they do. It does this by retracing the pathway of discovery and innovation described in historical accounts, and combining this historical research with artisanal, tacit, and causal knowledge gained from synthesizing new daguerreotypes in the laboratory. Admired for its astonishing clarity and holographic tones, each daguerreotype contains a unique material story about the process of its creation. Clues from the historical record that report improvements in the art are tested in practice to explicitly understand the cause for effects described in texts and observed in historic images. This approach raises awareness of the materiality of the daguerreotype as an image, and the materiality of the daguerreotype as a process. The structure of this thesis is determined by the techniques and materials of the daguerreotype in the order of practice related to improvements in speed, tone and spectral sensitivity, which were the prime motivation for advancements. Chapters are devoted to the silver plate, iodine sensitizing, halogen acceleration, and optics and their contribution toward image quality is revealed. The evolution of the lens is explained using some of the oldest cameras extant. Daguerre’s discovery of the latent image is presented as the result of tacit experience rather than fortunate accident.