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Rediscovery of the Elements Thallium, Crookes, and Lamy

With the development of spectroscopic analysis by Bunsen and Kirchhoff and their discovery of cesium and (1860-1861),1i the hunt was on for more III element discoveries using this new tool. Almost immediately, thallium was independently discovered by (1832–1919) and Claude-Auguste Lamy (1820–1878) (Figure 1).

At an early age Crookes developed a passion The Role of the Independent Editor. for photography, a hobby he pursued in his Modern research journals, such as The Journal of Brook home laboratory built for him by the American Chemical Society, utilize a formal his parents in 1851 (Figure 2). Here he devel- protocol of submission and peer review. In ear- oped new photographic techniques which lier years, however, it was common for a journal James L. Marshall, Beta Eta 1971, and required a wide broadening of his chemical to be owned and/or managed by an indepen- Virginia R. Marshall, Beta Eta 2003, knowledge. Blending his expertise in photogra- dent editor free to pontificate on various mat- Department of Chemistry, University of phy and chemistry, he designed instrumenta- ters. Often a journal would be more easily rec- North Texas, Denton, TX 76203-5070, tion and devised techniques in the spectroscop- ognized by the editor’s name, e.g., “Gilbert’s [email protected] ic examination of chemical substances. Hence, Annalen” (Annalen der Physik) or “Liebig’s by the time Bunsen discovered cesium spectro- Annalen” (Annalen der Chemie). For example, scopically in 1860, Crookes had already the editor Ludwig Wilhelm Gilbert (1769–1824) Crookes, the “Commercial Scientist.”2a launched his own search for new elements. would editorialize on on the significance of Crookes was an entrepreneur and scientific When his old mentor Hofmann needed a spec- Döbereiner’s Triads1g (precursor to the Periodic journalist with research achievements in chem- troscope in 1861 for a demonstration lecture on Table 1f), or he would suggest alternate possible istry, physics, and photography. His many Bunsen and Kirchhoff at the new South names for Stromeyer’s new element isolated inventions included the Crookes tube, the Kensington Museum, he turned to Crookes for from zinc1n—not only “Kadmium,” but also radiometer, and the spinthariscope (Note 1), the only high quality instrument equal to the “Junonium” and “Melinium.” Berzelius in his and he was awarded Fellowship of the Royal task in the entire British Isles. Jahres-Bericht über die Fortschritte der Chemie und Society (1863), knighthood (1897), the Davy Medal (1888), and the Order of Merit (1910). William Crookes was born to Joseph (1792–1884) and Mary neé Scott (1806–1884) Crookes; Joseph was a well-to-do tailor with a home and shop on Regents Street on the west end of London with its prospering gentry (Figure 2). Soon the family would move west- ward with expanding London. William’s schooling was gained at the new Royal College of Chemistry (Figure 3), founded in 1845 by Prince Albert (consort of Queen Victoria) who was keen on promoting the technology of Great Britain.3 Using the German model, Albert invited August Wilhelm von Hofmann (1818–1892) from the of Justus von Liebig (University of Giessen). At the Royal College Crookes researched selenocyanides (- Figure 1. Claude-Auguste Lamy (left) and William Crookes (middle) are shown when thallium was discov- SeCN compounds)4 using material procured by ered and characterized (early 1860s). Crookes lived well into his eighties and his elderly portraits (right) Hofmann from the Mountains of with his classic waxed mustache and goatee, at the apex of his career, are more familiar in the biographical Germany.5 literature. Lamy did not live so long after the thallium work, and is only known by this portrait.8

62 THE HEXAGON/WINTER 2011 Figure 3. The Royal College of Chemistry at 299 Oxford Street, where William Crookes was trained in chemistry and published his first paper on selenocyanides. Today this site is occupied by a men’s apparel store. By 1872 the institution had moved to New Kensington (200 meters west of the Figure 2. Sites pertaining to William Crookes in London (asterisk denotes edifice no longer exists). present Science Museum) and by 1907 had Father’s tailor shop,* Crookes’ birthplace, 143 Regent St.–N51° 30.68 W00° 08.35. evolved to the modern Imperial College (N51° Family home* 1846–1856 in Brook Green (Masborough House)–N51° 29.72 W00° 13.03. 29.86 W00° 10.66), where the original dedication Royal College of Chemistry, founded 1845, 16 Hanover Square (N51° 30.86 W00° 08.67); then (in stone laid by Prince Albert in 1846 is on display. 1848) 299 Oxford Street* where Crookes attended–N51° 30.89 W00° 08.69. Crookes’ home* 1857–1879, 20 Mornington Road 1857–1878, discovered thallium and performed deposits. In his following publication7 he cate- spiritualism experiments here–N51° 32.08 W00° 08.58. gorized his new element as a “,” and Crookes’ home 1880–1919, 7 Kensington Park Gardens, Notting Hill–N51° 30.69 W00° 12.16. he named it “thallium” (“thallos,” Greek for Science Museum, Exhibition Road, South Kensington, London, wealthy repository of Crookes’ exhibits— “green budding twig”). N51° 29.86 W00° 10.44. Crookes was a meticulous observer, careful Publishing houses of William Crookes. Wine Office Court, site of Crookes’ periodical Chemical News not to confuse stray lines with new elements. 1861–1867 (there were also several other sites in the general locality during the life of the journal)–N51° He had previously corrected others who had 30.86 W00° 06.43. “discovered” new elements— for example, John NOT SHOWN: F. W. Herschel (1792–1871; son of William Home at 15 Stanley St. [now Ovington St.] in Brompton (0.7 km east of Science Museum), residence in Herschel 1738–1822, discoverer of the planet 1856 with new bride Ellen Humphrey (1836–1916) before moving to Mornington Road–N51° 29.73 W00° Uranus) in his naive exuberance originally 09.90. interpreted the manifold spectral lines now Royal Institution, 21 Albemarle St. (300 meters southwest of Regent Street), exhibits on Crookes and other appearing in modern spectroscopes as new ele- scientists–N51° 30.58 W00° 08.55. ments— which he named junonium, vestium, , asataeum, and hebeium—until Mineralogie1h coined the term “catalyst” for his years past his death (Figures 4, 5). In this jour- more careful study showed the lines belonged concept of a special agent in plants, anticipating nal Crookes emphasized commercial chemistry to known elements.6 In Crookes’ study of thal- enzymes by almost half a century. The but did not hesitate to venture into many areas lium,5a he cautiously precluded all other possi- announcement in the Western World of the of pure research. And it was in this medium bilities by both spectroscopic and chemical spurious “vestium” by Sniadecki1l and its rejec- that he announced his own discovery of thalli- means, in all 55 other known and met- tion by the French Science Academy was made um, the “first element discovered by an alloids, as well as the gases and carbon.5 by Jean-Claude de La Métherie (1743–1817) in Englishman since [Sir Humphry] Davy’s dis- his private Journal de physique, de chimie, d’his- covery of the alkali metals.” 6 The Surprise at the International Exhibi - toire naturelle et des arts. In The HEXAGON tion of 1862. Eager to introduce his new ele- “Discovery” series we have seen back-and- The Discovery of Thallium. Crookes was ment at the 1862 International Exhibition at forth discussions of Hevesy and Coster’s hafni- caught up in the race to “discover a new ele- Hyde Park in London, Crookes received a rude um and Urbain’s celtium,1m Soddy’s transmu- ment before they ran out.”1m Returning to the shock— another scientist, a Frenchman tating elements,1k Rutherford’s atom,1k and Harz Mountains sample previously used in his Claude-Auguste Lamy (1820–1878), a professor Moseley’s atomic numbers,1j all discussed in selenocyanide studies, Crookes subjected it to of the Université de Lille (northeast France), Nature, the journal founded in 1869 by Joseph spectral analysis. His observation filled him was bringing his own exhibit of thallium. Norman Lockyer (1836–1920); co-discoverer of with excitement: “Suddenly a green flash Lamy 8 was born in Ney, in the Jura region of solar helium. And lastly there was William appeared before my eyes!”5 (Figures 6,7) He southeast France. He was the son of Désiré Crookes, who after two years as editor of vari- surmised that the element was of the “ (1782–1865) and Rosalie neé Melet ous photographic journals, in 1859 founded family,”5 because sulfur, , and telluri- (1796–1853) Lamy; Désiré was a career officer Chemical News which lasted for 73 years, 13 um were known to occur together in in the major battles of Napoleon I. Claude-

WINTER 2011/THE HEXAGON 63 III achieving hisreputation withthalliumthere, professor ofbiology(Figures 9,10). After who was firstdeanoftheUniversityaswell physics (Figure 8), along withLouisPasteur France (UniversitédeLille)astheprofessor of the newly foundedUniversitéLilleNord de University ofParis in 1851. In1854hejoined Limoges, thenfinishedhisdoctorate atthe uating in1842Lamy taughtatLille, then the two becameclosefriendsthere. After grad- Pasteur (1822–1895), alsofrom theJura region; Cécile HonorineKuhlmann (1832–1906), 64 thallium. was able toprepare sizableamountsofmetallic abundant supplyofthisnew element, Lamy strong green linein hislaboratory. With suchan with whichLamy immediatelyobserved the 11). Kuhlmann alsolentLamy aspectroscope proved tobe arichsource ofthallium (Figure suburb ofLille)whosesulfuric acid factory Kuhlmann’s company hadabranch in Loos(a ist CharlesFrédéricKuhlmann (1803–1881). daughter oftheprosperous chemicalindustrial- Picasso). et Manufactures inParis (today theMusée Lamy moved in1879tol’ÉcoleCentral des Arts Figure 4. Wine OfficeCourt, thesiteofCrookes minum. Deville (1818–1881)madehisfamewithalu- Supérieure, where Henri-Étienne Sainte-Claire Auguste Lamy studiedatÉcoleNormale ed here until1665. Itpresently holds English language, livedhere 1748–1759. The nameofthecourtisderivedfromExciseOfficethatexist- Georgian atmosphere ofearliertimes. SamuelJohnson, whowrotethefirstcomprehensive dictionaryofthe In 1854Claude-AugusteLamy married 1d 1e There Lamy metfellow-studentLouis Ye OldCheshire Cheese 9,10 11 8 ized itasa should becredited withthediscovery ofthe to theaidofLamy. Dumasargued thatLamy Chemical News foreigners!” one expectwhenthemajorityofjurors were would “What Crookes protested bitterly— Lamy aprizefor his accomplishment. Chemical News he publishedDumas’ (translated) articleinhis Jean-Baptiste André Dumas(1800–1884) International scene. Meanwhile, thefamed which gave considerable weighttothe credentials Fellow oftheRoyal Society—new zeal forpriority, ledtohisbeingelectedasa da campaign, coupledwithageneral British “had areputation toestablish.” Crookes andLamy this priorityissue—both control ofaBri by A. J. Balard, ofbromine fame, ingot exhibit stoodoutbecausehehadprepared an thallium inafullchemicalstudy, Lamy’s Crookes hadprepared many derivatives of diately disputedby Crookes). Although proclaimed itwas asulfidederivative (imme- merely afew grains ofdarkpowder—and inspected Crookes’ sampleoftheelement— since Crookes hadoriginallycharacter- Crookes hadtheadvantage ofimmediate At theLondonExhibitionof1862, Lamy of themetal. The Exhibitionjury, headed metalloid 2a (see nextfigure). . The fightwas on. Muchrode on publishing houses1861–1867, retains the 12c tish journal, andhispropagan- . 12 To thecredit ofCrookes, 2a 1b awarded 1e came element inthealuminumfamily. and by LotharMeyer, bothofwhomplacedthe few years later(1869)by DimitriMendeleev was clarifiedby thePeriodic Table presented a (+1 and+3). Thallium’s proper categorization ity, andwas capableofmultipleoxidationstates appearance, highdensity, andchemicalreactiv- thallium more closelyresembled (Pb)in different animalpartsstitchedtogether. Indeed, were firstthoughttobeahoax, acompositeof taxidermic specimensofthis Australian species platypus] ofmetals,” referring tothefactthat Dumas dubbeditthe “ornithorincus [duckbill However, otherproperties were more puzzling; alkali metals(Li, Na, K, Rb, Cs)(Figure 7). trum was strong andsharp, justasthoseofthe form oxidesoftheformulaM must beamemberofthealkalimetals:Itcould erate )andthefinalreaction roasting chamber(whichheatedpyrites togen- inserted anintermediatechamber between the cleaner methodofpreparing sulfuricacid. He by Kuhlmann himself preparing large amounts ofthalliumwas given The reason why Lamy was sosuccessfulin Lamy andDumas Christopher Wren andfinishedby1697. background isSt. Paul’s Cathedral, builtbySir Twain, and Theodore Roosevelt. The domeinthe of TwoCities Charles Dickens(mentioningthetavernin 1666. Patrons haveincludedSamuelJohnson, in thatyearbecauseofthegreat Londonfire of sawdust-covered floors, datingfrom1667, rebuilt a richheritageof Tutor windows, oakpanels, and Figure 5. THE HEXAGON/ Ye OldCheshire Cheese 12 13 who haddeveloped a argued thatthallium ), SirArthurConanDoyle, Mark 2 WINTER 2011 O, anditsspec- 1f is apubwith A Tale Figure 7. The emission (flame) spectra of the alkali metals (upper five) are relatively simple and facilitated Bunsen’s discovery of cesium (1860) and rubidium (1861).1i Owing to their fortuitously simple spectra, thallium (one green line at 535.0 nm) was then promptly discovered by Crookes (1861) and indium1a (two lines at 451.1 and 410.2 nm) by Reich and Richter (1863). Even the “monochro- matic” yellow spectrum of sodium exhibits a close doublet (589.6 nm and 589.0).

Figure 6. In the Science Museum of South Kensington, London, are many exhibits on Crookes, including (top) the laboratory notebook of William Crookes, documenting his observation of the green spectral thallium line, and (bottom) his collection of thallium compounds. (A collection of Lamy’s thallium compounds resides in the biblio- theque de l’École Normale Superieure Physique, 24, Rue Lhomond, Paris, France–N48° 50.57 E02° 20.82).

chamber.13 This intermediate chamber was designed to separate out nonvolatile impurities ( as the main culprit). When this non- volatile deposit was taken up in aqua regia and diluted with water, copious amounts of yellow thallium sesquisulfide hexagonal 10 (3TlCl• TlCl3 , or Tl2Cl3 ) could be collected. (It was now clear that in previous manufactory designs, the thallium had been carried on to become a contaminant in the final .) Another reason for Lamy’s success was that his taken from Theux, Belgium, were blessed with a greater concentration of thalli- um. Crookes finally found alternative sources for thallium, but Lamy’s good fortune allowed an initial burst of research that rapidly caught up with Crookes. The bitter debate between Lamy and Crookes continued for several years,6 until a Swede christened the first thallium-con- taining .”14a Figure 8. Sites pertaining to Lamy in Lille (asterisk denotes edifice no longer exists): The Discovery of Crookesite by Carnot College (original site of Université de Lille,* where Lamy researched thallium),–43, Boulevard Nordenskiöld. Readers of The HEXAGON may Carnot–N50° 38.38 E03° 03.99. recall that Berzelius discovered selenium1h in a Usine [factory] Frédéric Kuhlmann,* source of thallium for Lamy, 22 rue Georges Clemenceau, Loos– sulfuric acid manufactory in Gripsholm, N50° 37.28 E03° 00.45. Sweden, in 1817. Half a decade after Crookes Rue d’Esquermes sugar beet manufactory,* whose lactic acid problem was solved by Louis Pasteur – announced his discovery of thallium, Adolf E. N50° 37.37 E03° 02.45. Nordenskiöld (a Swedish arctic explorer and Palais des Beaux, Place de la République, marble bust of Frédérick Kuhlmann by Albert-Ernest Carrier- mineralogist, also a biographer of Scheele1c) Belleuse (1870)–N50° 37.88 E03° 03.67. was rummaging through old selenide Pasteur Institute, devoted to biochemical research, Blvd Louis XIV–N50° 37.74 E03° 04.47.

WINTER 2011/THE HEXAGON 65 III lmnslnhnm “didymium,”elements lanthanum, erbium, and student ofBerzelius andthediscoverer ofthe tions ofCarlGustafMosander(1797–1858), a these specimenscouldbetraced backtocollec- taining upto19percent ofthallium!Some but alsofoundotherunidentifiedminerals con- 66 postulating bacteriaasthesource oftheproblem. InLillePasteur solvedtheproblemofruinouslacticacidproductionatasugarbeetfactoryby 1857.” disk rimreads [translated]—“Tribute toLouisPasteur, foundedhere thescienceofmicrobiology. Lille his workonthallium. The monumentintheforeground isinmemoryofLouisPasteur; theplaqueon Figure 10. CarnotCollegenowoccupiestheoriginalsiteofUniversitédeLillewhere Lamyperformed eucairite (AgCuSe)andberzelianite (Cu in Stockholmcollections. Heidentified department, where Lamydidhiswork, wasonthepremier étage(secondfloor). [high school]Faidherbe, before NapoleonIIIfounded the UniversitédeLilleatthissitein1854. The physics Figure 9. This wasthebuildingwhere Lamyperformedhisthalliumresearch. ItwasoriginallytheLycée 2 Se) Swedish masters, he concluded, apparently inal article (now knowntobeCu thallium intheir blowpipestudies. surely observed thevividgreen flame colorof BerzeliusandMosander “keen-eyed andalert” ized crookesite, terbium. 1h Nordenskiöld isolatedandcharacter- 14a Nordenskiöld musesthatthe 14 describing itas(Cu,Ag,Tl)Se 7 (Tl,Ag)Se 4 ). 15 In hisorig- 1a These lengthy (11-page)obituary have thebettercase TheFrench thinkthey coverers ofthallium. texts credit bothCrookes andLamy asco-dis- been named “lamyite.” butnonehas — thallium minerals discovered name Crookes’ metal, he chose “crookesite” afterthediscoverer ofthe “observed itfirst.” discoverers, buthehonored Crookes whohad credited Crookes andLamy asindependent written pages,” Louis Pasteur inParis, archived in “four type- his many honorsandawards. “Cattle Plague” (phenolasanantiseptic);and Wheat Problem” (nitrogen fertilizers), andthe sewerage andsanitationdeficiencies, “The as hesoughtways tosolvesuchproblems as Psychical Research); service tohiscommunity (Crookes was president oftheSocietyfor proof whilethe “spiritualists” onlyneededfaith ly investigated thepsychicalforce, requiring dabblings inspiritualismwhere heintellectual- spectroscopic verificationofhelium;even his and scientificdiscoveries, includinghisfurther editorship of ble beginningstogreat achievements including Crookes’ successstory asheworked from hum- istry, andfriendofthedeceased. Tilden lauds biographer andresearcher interpenechem- written by William A. Tilden (1842–1926), noted mineral namedinhishonor. But Crookes seized onNordenskiöld’s new appreciate theextreme toxicnature ofthallium. ognizing itasametal. Lamy was alsothefirstto duce large ingotsofthenew element, thusrec- new chemicalelement”! Englishman sinceDavy tohave identifieda this clinchedit:Hereally was “the first in 1873. Pasteur emphasizedLamy’s triple ing présidentde la Sociétéfrançaise de chimie scientist of “the first order,” eventually becom- (principally thallium), Lamy was praised asa evil.” With majoraccomplishments inchemistry ple man, upright, fearingGodandshunning episode withUrbainandlutetium asintheFrench just — most importantly you as thediscoverer ofanelement, notonlymust episode mightbe:ifyou want toberecognized Lamy’s eulogywas delivered by hismentor green toazure blue. omnipresent , whichcanappearemerald mistook thegreen flameof thalliumforthatof tfrt There have beensome50different it first. Priority ofdiscoverythallium. The legacyofCrookesandLamy. A historicallessonofthis “Rediscovery” see 14b Chemical News it first, butyou must in hisoriginalarticle THE HEXAGON/ Chemical News 8 who describedLamy asa“sim- 14a 14a 2a At last, Crookes thought, —Lamy was abletopro- —Lamy 15 the Swedeexplained 2 16 ; many inventions 14a of Crookes was WINTER 2011 14b publish he specifically 1m Although in you must — it first, but Most The 4. W. Crookes, Q. J. Chem. Soc., 1852, 4, 12–20. 5. W. Crookes, (a) Chem. News, 1861, 3, 193–194; (b) reprinted in W. Crookes, Phil. Mag., 1861, 21 (4th series, no. 140), 301–305. 6. F. A. J. L. James, Notes and Records of the Royal Society of London, 1984, 39(1), 65–90. 7. W. Crookes, Chem. News, 1861, 3, 303. 8. Bulletin Municipal, Commune de Ney, Numéro 32, 15 mars 2011, 20–22. 9. C. A. Lamy, (a) Comptes rendus, 1862, 54, 1255–1258; (b) English translation Chem. News, 1862, 6, 29–30. 10. M. A. Lamy, De l’existence d’un nouveau metal, le thallium, 1862, L. Daniel, Lille. 11. J. G. Smith, Metals Rev., 1988, Figure 11. Appearance of the Loos factory site today. The sign on the headquarters building is expanded in 32(2), 84–90. the lower left inset. “Chemical products of Loos. Factory Frederic Kuhlmann/Chemilyl.” The thallium-bear- 12. J. B. Dumas et al., (a) Comptes rendus, ing used in sulfuric acid manufacture here in the 1860s was obtained from Le Rocheux Mine, 1862, 55, 866–872; (b) Annales de Oneux, Belgium (200 km east; N50° 32.43 E05° 49.83). Chimique et Physique, 1863, 67, 418–427; (c) English translation Chem. News, 1863, sense of “honor, discipline, and duty,” carrying 1940s by mailing in 15¢ and the top of a KIX 7, 14–16. on the tradition of his father who was among breakfast cereal boxtop. 13. F. Kuhlmann, Comptes rendus, 1863, 56, those who “carried the flag gloriously in all the Note 2. The father Désiré Lamy was wound- 171–173. capitals in Europe during the Napoleonic cam- ed and captured in the Moscow campaign of 14. M. A. E. Nordenskiöld (a) Ofversiht of paigns.” (Note 2) 1812. After he was released he participated in Kongl. Vetenscapsakademiens forhandlingar, the 1815 Waterloo defeat and then returned 1866, 23, no. 10, 361–367; (b) Chem. News, Next episode: In the following HEXAGON, home to have five sons. The eldest son (Claude- 1867, 16, 29. we will travel to the Harz Mountains to explore Auguste) turned to science and the other four 15. Dana’s New Mineralogy, 8th Ed., John the source of Crookes’ thallium. served in the military; one was killed in 1863 Wiley & Sons, N.Y. 1997. during the Maximilian Affair during the Battle Acknowledgments. of Puebla, Mexico (which is commemorated 16. W. A. Tilden, Proc. Roy. Soc. London, 1919, The authors are indebted to the following today in Mexico as “Cinco de Mayo”). 96A, 1–9; reprinted J. Chem. Soc., Trans., persons for their gracious assistance in procur- 1920, 117, 444–454. ing archival information for the discoverers of References. thallium. For Lamy: Dr. Pascal Devolder, 1. J. L. Marshall and V. R. Marshall, Université des Sciences et Technologies de The HEXAGON of Alpha Chi Sigma (a) A Note for Contributors Lille, Villeneuve d’Ascq, France. For Crookes: 2001, 92(2), 20–22; (b) 2001, 92(3), 36–39; We certainly appreciate the added appeal Prof. William Griffith, Imperial College, (c) 2005, 96(1), 8–13; (d) 2006, 97(2), 24–29; of pictures in The HEXAGON. When London; Prof. Frank A.J.L. James, Royal (e) 2007, 98(1), 3–9; (f) 2007, 98(2), 23–29; taking photos for submission, please: Institution, London; and Emeritus Prof. William (g) 2007, 98(3), 50-55; (h) 2007, 98(4), • Always use a flash indoors. 2a Brock (Crookes’ biographer ), University of 70–76; (i) 2008, 99(3), 42–46; (j) 2010, 101(3), • Do not edit or alter your images. Leicester UK. 42–47; (k) 2010, 101(4), 68–71,74; (l) 2011, The HEXAGON production staff can and will determine if an image needs color 2011 102(2), 20–24; (m) , 102(3), 36–41; (n) correcting or additional processing. Notes. 2012, 103(1) to be published. • Set your digital camera quality to its Note 1. The Crookes tube was a low-pres- 2. The two biographies of Crookes are (a) highest setting with the least compression. sure discharge tube which emanated “cathode W. H. Brock, William Crookes (1832–1919) Photos that are less than 8 inches wide at rays” (electrons). The radiometer is an evacuat- and the Commercialization of Science, 2008, 72 dpi, or that have a file size of under ed bulb enclosing a spindle with vanes, black- Ashgate, Hampshire, England (“Thallium” 1 megabyte, may be too small for print production. ened and silvered on opposite sides, which chapter pp 61–82), and (b) E. E. F. D’Albe, • Please send us the image file that is rotates when exposed to light; this device is 1923 The Life of Sir William Crookes, , directly from the camera. Photos that are common in educational institutions. The London, Fisher Unwin (1924, D. Appleton spinthariscope was a device for observing indi- extracted from iPhoto albums, Facebook & Company, N.Y). pages or Word documents have file sizes vidual scintillations from a radioactive alpha that have been compromised. source (Ra or Po) on a phosphorescent sul- 3. R, G. Williams and A. Barrett, Imperial • Print photos are welcome! fide sceen—old-timers may recall the “Atomic College. A Pictorial History, 1988, Imperial Bomb Ring,” which could be ordered in the late College Archives, London.

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