Paul-Émile Lecoq de Boisbaudran

<h2 id="biography">Biography</h2>
Lecoq de Boisbaudran was a member of a noble family of <a href="/facts/Huguenots/x2FcqQ8J">Huguenots</a> from the <a href="/facts/French_provinces/7fwpoSWA">French provinces</a> of <a href="/facts/Poitou/0IneyHsA">Poitou</a> and <a href="/facts/Angoumois/uLQsv5h2">Angoumois</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a><a class="footnote-ref" id="fnref:5" href="#fn:5">5</a> The Huguenots were French <a href="/facts/Protestant/NXja4K3g">Protestants</a>, a population that was devastated during the <a href="/facts/French_Wars_of_Religion/43pYXFXr">French Wars of Religion</a> (1561–1598). The <a href="/facts/Edict_of_Nantes/3KXjorpK">Edict of Nantes</a> (1598) granted substantial <a href="/facts/Civil_rights/DBK7m6s2">civil rights</a> to the <a href="/facts/Huguenots/x2FcqQ8J">Huguenots</a> even though it maintained <a href="/facts/Catholicism/rJ4F4gqH">Catholicism</a>'s position as the established religion of <a href="/facts/Frances_McDormand/r2oD3ok9">France</a>. The Edict of Nantes was overturned by the <a href="/facts/Edict_of_Fontainebleau/oUgaDaGp">Edict of Fontainebleau</a> (1685), which officially sanctioned persecution of Protestants.<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a> The Lecoq de Boisbaudran family was of considerable fortune until the <a href="/facts/Revocation_(band)/FnJgAWvk">revocation</a> of the <a href="/facts/Edict_of_Nantes/3KXjorpK">Edict of Nantes</a>, after which much of their property was confiscated and sold.<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a>
Paul-Émile (Francois) Lecoq de Boisbaudran was a son of Paul Lecoq de Boisbaudran (1801–1870) and his wife Anne Louise.<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a> Paul Lecoq de Boisbaudran established a successful <a href="/facts/E_%2526_J_Gallo_Winery/0X0XUAFh">wine business</a> in <a href="/facts/Cognac%2c_France/DWmJqFfX">Cognac</a>, benefiting from the hard work of the entire family including young Paul-Émile.<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a><a class="footnote-ref" id="fnref:10" href="#fn:10">10</a>
Anne Louise Lecoq de Boisbaudran was well educated and taught her son Paul-Émile history and foreign languages, including English. He obtained the syllabus of the <a href="/facts/%25C3%2589cole_Polytechnique/0DS7aMaR">École Polytechnique</a>, and he studied the books assigned in its courses. In this way, he was self-taught as a scientist. As such, de Boisbaudran is an example of an <a href="/facts/Autodidact/qCKsxtdc">autodidact</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a> With the support of his family, he assembled a modest <a href="/facts/Chemical_laboratory/kqR3Vtx9">chemical laboratory</a> on the second floor of their home on the Rue de Lusignan. In this laboratory, he repeated the experiments that he had studied in books. Through these experiments, he developed his theories of spectroscopy and made most of his discoveries, including the isolation of gallium.<a class="footnote-ref" id="fnref:12" href="#fn:12">12</a><a class="footnote-ref" id="fnref:13" href="#fn:13">13</a>
Lecoq de Boisbaudran married Jeannette Nadault-Valette (1852–1926) on <a href="/facts/Assassination_of_Benazir_Bhutto/MXfGJQyF">27 December 1897</a>. They had no children.<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> He developed <a href="/facts/Ankylosis/YKky8W8w">ankylosis</a> of the joints, and failing health hindered his work after 1895. He died in <a href="/facts/1912/6y6T0vzf">1912</a>, at the age of 74.<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a>

<h2 id="research">Research</h2>
Lecoq de Boisbaudran's early investigations focused on understanding the <a href="/facts/Phenomenon_(TV_series)/E8ubaVbI">phenomenon</a> of <a href="/facts/Supersaturation/YaTN0D1L">supersaturation</a>, in which substances can exist in solution in higher <a href="/facts/Concentration_Camps_Inspectorate/gg3yXP4g">concentrations</a> than is possible under normal conditions. He showed that contact of supersaturated solutions with crystals of an <a href="/facts/Isomorphism_(crystallography)/f1XqB5Iq">isomorphous</a> <a href="/facts/Salt_(chemistry)/lsSKwGpn">salt</a> causes the substance to precipitate from the solution. He further showed that many <a href="/facts/Anhydrous/A7B0fDLE">anhydrous</a> salts can be <a href="/facts/Dissolved_parliament/orKBroEw">dissolved</a> to create a supersaturated solution. These investigations were carried out from 1866 to 1869.
In 1874 Lecoq de Boisbaudran found that certain <a href="https://www.youtube.com/@RoyalPear">crystal faces</a> dissolve more rapidly than other crystal faces. Specifically, he found that <a href="/facts/Octahedral/G38q92xW">octahedral</a> faces are less readily soluble than cubic faces in the case of <a href="/facts/Ammonium_alum/XNyYBFJ3">ammonium alum</a> crystals.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a>
Lecoq de Boisbaudran made major contributions to the then-new science of spectroscopy, which relates to the interaction of light and matter. He applied spectroscopy to characterize elements, particularly the <a href="/facts/Rare-earth_element/PQSUQumk">rare-earth elements</a>.<a class="footnote-ref" id="fnref:17" href="#fn:17">17</a><a class="footnote-ref" id="fnref:18" href="#fn:18">18</a><a class="footnote-ref" id="fnref:19" href="#fn:19">19</a> He developed a theoretical framework of spectroscopy, based on <a href="/facts/Molecular_vibrations/Y0ovRukI">molecular vibrations</a>. Theorizing that spectral frequencies relate to the atomic weight of an element, he recognized spectral trends based upon atomic masses.<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a>
Boisbaudran developed new experimental apparatus and used these to carry out spectral analyses of various chemical elements.<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a> Through systematic experimentation, he analysed spectra of 35 elements, using the <a href="/facts/Bunsen_burner/Q4BpEuFU">Bunsen burner</a>, electric spark or both to induce <a href="/facts/Luminescence/1QkIWyUj">luminescence</a> of samples of the elements.<a class="footnote-ref" id="fnref:22" href="#fn:22">22</a> The results of his early investigations were published in his Spectres lumineux : spectres prismatiques et en longueurs d'ondes destinés aux recherches de chimie minérale (1874).<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a>
To observe <a href="/facts/Spark_spectra/5s0wg1sX">spark spectra</a> in his experimental protocols, he typically placed a solution of a salt in a sealed glass tube, with a platinum wire in the solution as a negative pole, and another platinum wire above the surface of the liquid as a positive pole.<a class="footnote-ref" id="fnref:24" href="#fn:24">24</a> In 1885, he experimented with reversing the polarity of the electric current. In this way, he obtained <a href="/facts/Phosphorescent/WshJFsKV">phosphorescent</a> bands in the spectra providing further insight into the spectral characteristics of various chemical elements. Using this apparatus, he discovered the <a href="/facts/Lanthanide/rt3XIRCl">lanthanides</a> <a href="/facts/Samarium/09K3kl93">samarium</a> (1880), <a href="/facts/Dysprosium/eMev6zGS">dysprosium</a> (1886) and <a href="/facts/Europium/dqmBm1vr">europium</a> (1890). In 1885, he also spectroscopically characterized <a href="/facts/Gadolinium/eLYUeScu">gadolinium</a> in 1885, an element previously discovered in 1880 by <a href="/facts/Jean_Charles_Galissard_de_Marignac/Iqe4UAHX">J. C. Galissard de Marignac</a>.<a class="footnote-ref" id="fnref:25" href="#fn:25">25</a>

<h3>Samarium</h3>

Lecoq de Boisbaudran discovered <a href="/facts/Samarium/09K3kl93">samarium</a> in 1879 after first isolating <a href="/facts/Samarium_oxide/2naE6cPc">samarium oxide</a>. He identified the presence of a new element by using spectroscopy to observe its characteristic sharp optical absorption lines.<a class="footnote-ref" id="fnref:26" href="#fn:26">26</a>
He named his new element "samarium"<a class="footnote-ref" id="fnref:27" href="#fn:27">27</a> after the mineral <a href="/facts/Samarskite/q79Axajv">samarskite</a> from which it was isolated. The mineral itself was earlier named for a Russian mine official, Colonel <a href="/facts/Vassili_Samarsky-Bykhovets/AYuKW2ot">Vassili Samarsky-Bykhovets</a>.<a class="footnote-ref" id="fnref:28" href="#fn:28">28</a>

<h3>Gallium</h3>

A significant achievement of Lecoq de Boisbaudran was his discovery of the element <a href="/facts/Gallium/EucevDs9">gallium</a> in 1875. Beginning in 1874, Lecoq de Boisbaudran investigated a sample of 52 kg of the mineral ore <a href="/facts/Sphalerite/5NumvnzR">sphalerite</a> obtained from the Pierrefitte mine in the <a href="/facts/Pyrenees/YJ38kInj">Pyrenees</a>. From it, he extracted several milligrams of gallium chloride. Using spectroscopic methods, he observed what appeared to be two previously unreported lines in the sample's spectrum, at wavelengths of 4170 and 4031 <a href="/facts/Angstroms/T5mjdd97">angstroms</a>.<a class="footnote-ref" id="fnref:29" href="#fn:29">29</a><a class="footnote-ref" id="fnref:30" href="#fn:30">30</a>

He continued his experiments using several hundred kilograms of crude zinc ore and in the same year isolated more than one gram of a near-pure metal by electrolysis of a solution of the metal in its form as a hydroxide compound, dissolved in <a href="/facts/Potassium_hydroxide/NBhPBuXc">potassium hydroxide</a> solution. Later he prepared 75 grams of gallium using more than 4 tonnes of crude ore. He confirmed its spectral characteristics, consisting of two spectral lines in the <a href="/facts/Violet_(color)/zcNJGApt">violet</a> portion of the spectrum of the mineral sphalerite. In this way, he ruled out the possibility that the spectral characteristics were an accident of the extraction process, rather than being an indication of a new element.<a class="footnote-ref" id="fnref:31" href="#fn:31">31</a><a class="footnote-ref" id="fnref:32" href="#fn:32">32</a>
He named his discovery "gallium", from the <a href="/facts/Latin/pM3Kge85">Latin</a> Gallia meaning <a href="/facts/Gaul/fSpNpRqy">Gaul</a>, in honor of his native land of France. It was later suggested that Lecoq de Boisbaudran had named the element after himself, since gallus is the Latin translation of the French le coq. Lecoq de Boisbaudran denied this suggestion in an article in 1877.<a class="footnote-ref" id="fnref:33" href="#fn:33">33</a> He published an account of his investigations on the new element in Sur un nouveau metal, le gallium (1877).<a class="footnote-ref" id="fnref:34" href="#fn:34">34</a>
De Boisbaudran calculated the atomic mass of gallium as 69.86, close to the currently accepted value of 69.723.<a class="footnote-ref" id="fnref:35" href="#fn:35">35</a><a class="footnote-ref" id="fnref:36" href="#fn:36">36</a> Unknown to Lecoq de Boisbaudran,<a class="footnote-ref" id="fnref:37" href="#fn:37">37</a> the existence of gallium had been predicted during 1871 by <a href="/facts/Dmitri_Mendeleev/xdouRrx8">Dmitri Mendeleev</a>, who gave it the name eka-aluminium. De Boisbaudran's discovery of gallium was significant support for Mendeleev's theory of the <a href="/facts/Periodicity_of_the_elements/umdGIfUb">periodicity of the elements</a>.<a class="footnote-ref" id="fnref:38" href="#fn:38">38</a><a class="footnote-ref" id="fnref:39" href="#fn:39">39</a><a class="footnote-ref" id="fnref:40" href="#fn:40">40</a>

<h3>Dysprosium</h3>

Lecoq de Boisbaudran experimented with the precipitation of rare earth compounds from water solution using potassium sulfate to induce precipitation. He then measured the spectra of solutions in which the liquid served as a positive pole. Lecoq de Boisbaudran noted a spectral band in the yellow-green portion of the spectrum, indicative of a new element. In 1886 he succeeded in isolating a purified sample of the source of the new spectral band. He named the element <a href="/facts/Dysprosium/eMev6zGS">dysprosium</a>, meaning "difficult to obtain" in the Greek language.<a class="footnote-ref" id="fnref:41" href="#fn:41">41</a><a class="footnote-ref" id="fnref:42" href="#fn:42">42</a>

<h3>Periodic classification of elements</h3>
Lecoq de Boisbaudran contributed to the development of the periodic classification of elements. This contribution occurred when he proposed that the newly discovered element <a href="/facts/Argon/QX6NRH6d">argon</a> was a member of a new, previously unrecognized, <a href="/facts/Chemical_series/YGBcUabv">chemical series</a> of elements that came to be known as the <a href="/facts/Noble_gas/j0yHMEAE">noble gases</a>.<a class="footnote-ref" id="fnref:43" href="#fn:43">43</a>

<h2 id="awards-and-honors">Awards and honors</h2>
For his accomplishments, Lecoq de Boisbaudran was awarded the Cross of the <a href="/facts/Legion_of_Honour/XmLQTz71">Legion of Honour</a> (1876),<a class="footnote-ref" id="fnref:44" href="#fn:44">44</a> 
the Bordin Prize from the French Academy of Sciencies (1872),<a class="footnote-ref" id="fnref:45" href="#fn:45">45</a> 
the <a href="/facts/Davy_Medal/uoqf9fT9">Davy Medal</a> (1879)<a class="footnote-ref" id="fnref:46" href="#fn:46">46</a><a class="footnote-ref" id="fnref:47" href="#fn:47">47</a>
and the Prix Lacaze of 10,000 francs (1879).<a class="footnote-ref" id="fnref:48" href="#fn:48">48</a><a class="footnote-ref" id="fnref:49" href="#fn:49">49</a> In 1888 he was elected a foreign member of the British <a href="/facts/Royal_Society/KI5yXCuV">Royal Society</a>.<a class="footnote-ref" id="fnref:50" href="#fn:50">50</a>

<h2 id="sources">Sources</h2>
<ul><li> This article incorporates text from Obituary notices, by <a href="/facts/William_Ramsay/fGzWlHlP">William Ramsay</a>, a publication from 1913, now in the <a href="/facts/Public_domain/YWKMDKw4">public domain</a> in the United States.</li></ul>

<h2 id="references">References</h2>

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<li id="fn:2">"Paul-Émile Lecoq de Boisbaudran | French chemist | Britannica". www.britannica.com. Retrieved 2 May 2023. <a href="https://www.britannica.com/biography/Paul-Emile-Lecoq-de-Boisbaudran" target="_blank">https://www.britannica.com/biography/Paul-Emile-Lecoq-de-Boisbaudran</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education. <a href="https://archive.org/details/discoveryoftheel002045mbp" target="_blank">https://archive.org/details/discoveryoftheel002045mbp</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Marshall, James L.; Marshall, Virginia R. (2008). "Rediscovery of the Elements: Yttrium and Johan Gadolin" (PDF). The Hexagon (Spring): 8–11. <a href="http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf" target="_blank">http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
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<li id="fn:7">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Marshall, James L.; Marshall, Virginia R. (2008). "Rediscovery of the Elements: Yttrium and Johan Gadolin" (PDF). The Hexagon (Spring): 8–11. <a href="http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf" target="_blank">http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Gardiner, J. H. (31 October 1912). "M. Lecoq De Boisbaudran". Nature. 90 (2244): 255–256. Bibcode:1912Natur..90..255G. doi:10.1038/090255a0. <a href="https://books.google.com/books?id=ExJLAQAAMAAJ&pg=PA255" target="_blank">https://books.google.com/books?id=ExJLAQAAMAAJ&pg=PA255</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">"Paul Emile Lecoq De Boisbauran | Encyclopedia.com". www.encyclopedia.com. Retrieved 2 May 2023. <a href="https://www.encyclopedia.com/people/science-and-technology/chemistry-biographies/paul-emile-lecoq-de-boisbauran" target="_blank">https://www.encyclopedia.com/people/science-and-technology/chemistry-biographies/paul-emile-lecoq-de-boisbauran</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Marshall, James L.; Marshall, Virginia R. (2008). "Rediscovery of the Elements: Yttrium and Johan Gadolin" (PDF). The Hexagon (Spring): 8–11. <a href="http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf" target="_blank">http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Fontani, Marco; Costa, Mariagrazia; Orna, Virginia (2014). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. p. 213. ISBN 978-0-19-938334-4. <a href="978-0-19-938334-4" target="_blank">978-0-19-938334-4</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
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<li id="fn:19">Marshall, James L.; Marshall, Virginia R. (2008). "Rediscovery of the Elements: Yttrium and Johan Gadolin" (PDF). The Hexagon (Spring): 8–11. <a href="http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf" target="_blank">http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
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<li id="fn:21">Marshall, James L.; Marshall, Virginia R. (2008). "Rediscovery of the Elements: Yttrium and Johan Gadolin" (PDF). The Hexagon (Spring): 8–11. <a href="http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf" target="_blank">http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/gadolin.pdf</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Lecoq de Boisbaudran, [Paul-Émile] (1874). Spectres lumineux : spectres prismatiques et en longueurs d'ondes destinés aux recherches de chimie. Paris: Gauthier-Villars. <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
<li id="fn:26">Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education. <a href="https://archive.org/details/discoveryoftheel002045mbp" target="_blank">https://archive.org/details/discoveryoftheel002045mbp</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></li>
<li id="fn:27">Boisbaudran, Lecoq de (1879). "Recherches sur le samarium, radical d'une terre nouvelle extraite de la samarskite". Comptes rendus hebdomadaires des séances de l'Académie des sciences. 89: 212–214. <a href="http://gallica.bnf.fr/ark:/12148/bpt6k3046j/f214.pagination" target="_blank">http://gallica.bnf.fr/ark:/12148/bpt6k3046j/f214.pagination</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></li>
<li id="fn:28">Hammond, C. R. (29 June 2004). "The Elements". Handbook of Chemistry and Physics (81st ed.). CRC press. ISBN 0-8493-0485-7. <a href="0-8493-0485-7" target="_blank">0-8493-0485-7</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></li>
<li id="fn:29">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></li>
<li id="fn:30">Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education. <a href="https://archive.org/details/discoveryoftheel002045mbp" target="_blank">https://archive.org/details/discoveryoftheel002045mbp</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></li>
<li id="fn:31">Lecoq de Boisbaudran, Paul Émile (1875). "Caractères chimiques et spectroscopiques d'un nouveau métal, le gallium, découvert dans une blende de la mine de Pierrefitte, vallée d'Argelès (Pyrénées)". Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences. 81: 493–495. <a href="#fnref:31" class="footnote-back-ref">↩</a></li>
<li id="fn:32">Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education. <a href="https://archive.org/details/discoveryoftheel002045mbp" target="_blank">https://archive.org/details/discoveryoftheel002045mbp</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></li>
<li id="fn:33">Weeks, Mary Elvira (1932). "The discovery of the elements. XIII. Some elements predicted by Mendeleeff". Journal of Chemical Education. 9 (9): 1605–1619. Bibcode:1932JChEd...9.1605W. doi:10.1021/ed009p1605. <a href="/wiki/Mary_Elvira_Weeks" target="_blank">/wiki/Mary_Elvira_Weeks</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></li>
<li id="fn:34">Lecoq de Boisbaudran, [Paul-Émile] (1877). Sur un nouveau metal, le gallium. Paris: s.n. <a href="#fnref:34" class="footnote-back-ref">↩</a></li>
<li id="fn:35">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></li>
<li id="fn:36">Gordin, Michael D. (11 December 2018). A well-ordered thing : Dmitrii Mendeleev and the shadow of the periodic table. Princeton University Press. pp. 36–38. ISBN 9780691172385. <a href="9780691172385" target="_blank">9780691172385</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></li>
<li id="fn:37">Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education. <a href="https://archive.org/details/discoveryoftheel002045mbp" target="_blank">https://archive.org/details/discoveryoftheel002045mbp</a> <a href="#fnref:37" class="footnote-back-ref">↩</a></li>
<li id="fn:38">Gordin, Michael D. (11 December 2018). A well-ordered thing : Dmitrii Mendeleev and the shadow of the periodic table. Princeton University Press. pp. 36–38. ISBN 9780691172385. <a href="9780691172385" target="_blank">9780691172385</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></li>
<li id="fn:39">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:39" class="footnote-back-ref">↩</a></li>
<li id="fn:40">Ebbing, Darrell; Gammon, Steven D. (2010). General chemistry (Enhanced., 9th ed.). Brooks/Cole Cengage Learning. p. 312. ISBN 9780538497527. In 1874 the French chemist Paul-Émile Lecoq de Boisbaudran found two previously unidentified lines in the atomic spectrum of a sample of sphalerite (a zinc sulfide, ZnS, mineral). Realizing he was on the verge of a discovery, Lecoq de Boisbaudran quickly prepared a large batch of the zinc mineral, from which he isolated a gram of a new element. He called this new element gallium. <a href="9780538497527" target="_blank">9780538497527</a> <a href="#fnref:40" class="footnote-back-ref">↩</a></li>
<li id="fn:41">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:41" class="footnote-back-ref">↩</a></li>
<li id="fn:42">Emsley, John (2011). Nature's Building Blocks: An A-Z Guide to the Elements. Oxford University Press. p. 130. ISBN 978-0-19-960563-7. <a href="978-0-19-960563-7" target="_blank">978-0-19-960563-7</a> <a href="#fnref:42" class="footnote-back-ref">↩</a></li>
<li id="fn:43">Spronsen, J. W. van (1969). The periodic system of chemical elements: A history of the first hundred years. Elsevier. p. 250. <a href="#fnref:43" class="footnote-back-ref">↩</a></li>
<li id="fn:44">Gordin, Michael D. (11 December 2018). A well-ordered thing : Dmitrii Mendeleev and the shadow of the periodic table. Princeton University Press. pp. 36–38. ISBN 9780691172385. <a href="9780691172385" target="_blank">9780691172385</a> <a href="#fnref:44" class="footnote-back-ref">↩</a></li>
<li id="fn:45">Hentschel, Klaus (2002). Mapping the spectrum : techniques of visual representation in research and teaching. Oxford University Press. pp. 118–120. ISBN 978-0198509530. <a href="978-0198509530" target="_blank">978-0198509530</a> <a href="#fnref:45" class="footnote-back-ref">↩</a></li>
<li id="fn:46">Brush, Stephen G. (2015). Making 20th century science : how theories became knowledge. Oxford University Press. pp. 161–166. ISBN 978-0-19-997815-1. <a href="978-0-19-997815-1" target="_blank">978-0-19-997815-1</a> <a href="#fnref:46" class="footnote-back-ref">↩</a></li>
<li id="fn:47">"Davy Medal". NNDB. Retrieved 28 December 2019. <a href="https://www.nndb.com/honors/624/000100324/" target="_blank">https://www.nndb.com/honors/624/000100324/</a> <a href="#fnref:47" class="footnote-back-ref">↩</a></li>
<li id="fn:48">"Academies et Societes Savantes". L'Année scientifique et industrielle. 24: 507. 1880. Retrieved 28 December 2019. <a href="https://books.google.com/books?id=pypGAQAAMAAJ&pg=PA507" target="_blank">https://books.google.com/books?id=pypGAQAAMAAJ&pg=PA507</a> <a href="#fnref:48" class="footnote-back-ref">↩</a></li>
<li id="fn:49">Gardiner, J. H. (31 October 1912). "M. Lecoq De Boisbaudran". Nature. 90 (2244): 255–256. Bibcode:1912Natur..90..255G. doi:10.1038/090255a0. <a href="https://books.google.com/books?id=ExJLAQAAMAAJ&pg=PA255" target="_blank">https://books.google.com/books?id=ExJLAQAAMAAJ&pg=PA255</a> <a href="#fnref:49" class="footnote-back-ref">↩</a></li>
<li id="fn:50">Ramsay, W. (1913). "Obituary notices: Paul Émile (dit François) Lecoq de Boisbaudran, 1838–1912". J. Chem. Soc., Trans. 103: 742–744. doi:10.1039/CT9130300742. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:50" class="footnote-back-ref">↩</a></li>
</ol>

Paul-Émile Lecoq de Boisbaudran open-in-new

Paul-Émile Lecoq de Boisbaudran