Editing Sodium silicate (section)

==History==
Soluble silicates of [[alkali]] metals (sodium or [[potassium]]) were observed by European [[alchemy|alchemists]] in the 16th century. [[Giambattista della Porta]] observed in 1567 that ''tartari salis'' (cream of tartar, [[potassium bitartrate]]) caused powdered ''crystallum'' (quartz) to melt at a lower temperature.<ref>{{cite book |last1=della Porta |first1=Giambattista |title=Magia naturalis sive de miraculis rerum naturalium, libri iiii |trans-title=Natural magic or on the miracles of nature, in four books |date=1569 |publisher=Guillaume Rouillé (Gulielmum Rovillium) |location=Lyon (''Lugdunum''), France |pages=290–291 |language=Latin}} See [https://books.google.com/books?id=Z9j1m8oXBlEC&pg=PA302 pp. 290–291], "''Crystallus, ut fusilis fiat''" (Quartz, so made molten)]</ref> Other possible early references to alkali silicates were made by [[Basil Valentine]] in 1520,<ref>{{cite journal |last1=Kohn |first1=C. |title=Die Erfindung des Wasserglas im Jahre 1520 |journal=Zeitschrift des Österreichischen Ingenieur-Vereines |trans-journal=Journal of the Austrian Engineer Association |date=1862 |volume=14 |pages=229–230 |trans-title=The invention of waterglass in the year 1520 |language=German |url=http://digital.onb.ac.at/OnbViewer/viewer.faces?doc=ABO_%2BZ228846906 }}</ref> and by [[Georgius Agricola|Agricola]] in 1550. Around 1640, [[Jan Baptist van Helmont]] reported the formation of alkali silicates as a soluble substance made by melting sand with excess alkali, and observed that the silica could be precipitated quantitatively by adding acid to the [[Solution (chemistry)|solution]].<ref>{{cite book |last1=van Helmont |first1=Johannes |title=Opuscula medica inaudita |date=1644 |publisher=Jost Kalckhoven (Jodocum Kalcoven) |location=Cologne, Germany |page=53 |language=Latin}} In Part I:  ''De Lithiasi'', [https://archive.org/details/bub_gb_GWOFpC0fDcAC/page/n51 page 53], van Helmont mentions that alkalis dissolve silicates:  "''Porro lapides, gemmae, arenae, marmora, silices, &c. adjuncto alcali, vitrificantur: sin autem plure alcali coquantur, resolvuntur in humido quidem: ac resoluta, facili negotio acidorum spirituum, separantur ab alcali, pondere pristini pulveris lapidum''." (Furthermore, stone, gems, sand, marble, silica, etc., become glassy by the addition of alkali: but if roasted with more alkali, they are dissolved in moisture: and the former weight of the stone powder is separated from the alkali and released by simply adding acid.)</ref>

In 1646, [[Johann Rudolf Glauber|Glauber]] made [[potassium silicate]], which he called ''liquor silicum'', by melting [[potassium carbonate]] (obtained by [[calcination|calcinating]] cream of tartar) and sand in a crucible, and keeping it molten until it ceased to bubble (due to the release of [[carbon dioxide]]). The mixture was allowed to cool and then was ground to a fine powder.<ref>{{cite book |last1=Glauber |first1=Johann Rudolf |title=Furni Novi Philosophici |trans-title=New Philosophical Furnace|date=1647 |publisher=Johann Fabel |location=Amsterdam, Netherlands |volume=2 |pages=136–137 |url=https://books.google.com/books?id=f-GomMQpnqYC&pg=PA136 |language=German}} See: ''"Wie durch Hülff eines reinen Sandes oder Kißlings auß Sale Tartari ein kräfftiger Spiritus kan erlanget werden."'' (How with the help of a pure sand or silica a powerful solution can be gotten from cream of tartar).</ref> When the powder was exposed to moist air, it gradually formed a viscous liquid, which Glauber called "''Oleum oder Liquor Silicum, Arenæ, vel Crystallorum''" (i.e., oil or solution of silica, sand or quartz crystal).<ref>(Glauber, 1647), [https://books.google.com/books?id=f-GomMQpnqYC&pg=PA138 p. 138]</ref>

However, it was later claimed that the substances prepared by those alchemists were not waterglass as it is understood today.<ref>{{cite journal |last1=Anon. |title=Die Erfindung des Wasserglases im Jahre 1520 |journal=Kunst- und Gewerbe-Blatt |date=1863 |volume=49 |pages=228–230 |url=https://books.google.com/books?id=ew8AAAAAMAAJ&pg=RA1-PA227 |trans-title=The invention of waterglass in the year 1520 |language=German}}
* Reprinted in:  {{cite journal |last1=Anon. |title=Die Erfindung des Wasserglases im Jahre 1520 |journal=Polytechnisches Journal |date=1863 |volume=168 |pages=394–395 |url=https://books.google.com/books?id=AAQ1AAAAMAAJ&pg=PA394 |trans-title=The invention of waterglass in the year 1520 |language=German}}
* Reprinted in:  {{cite journal |last1=Anon. |title=Die angebliche Erfindung des Wasserglases im Jahre 1520 |journal=Neues Repertorium für Pharmacie |date=1863 |volume=12 |pages=271–273 |url=https://books.google.com/books?id=uwQ9AAAAcAAJ&pg=PA27 |trans-title=The alleged invention of waterglass in the year 1520 |language=German}}</ref> That would have been prepared in 1818 by [[Johann Nepomuk von Fuchs]], by treating [[silicic acid]] with an alkali; the result being soluble in water, "but not affected by atmospheric changes".<ref>{{cite journal |last1=Nepomuk von Fuchs |first1=Johann |title=Ueber ein neues Produkt aus Kieselerde und Kali |journal=Archiv für die gesammte Naturlehre |date=1825 |volume=5 |issue=4 |pages=385–412 |url=https://books.google.com/books?id=-aE8AAAAYAAJ&pg=PA385 |trans-title=On a new product from silica and potash |language=German}} From page 386: ''"Ich erhielt es zuerst, vor ungefähr 7 Jahren"'' (I first obtained it about 7 years ago). 
* Reprinted in:  {{cite journal |last1=Nepomuk Fuchs |first1=Joh. |title=Ueber ein neues Produkt aus Kieselerde und Kali; und dessen nüzliche Anwendung als Schuzmittel gegen schnelle Verbreitung des Feuers in Theatern, als Bindemittel, firnißartigen Anstrichen u.s.w. |journal=Polytechnisches Journal |date=1825 |volume=17 |pages=465–481 |url=https://books.google.com/books?id=zbs-AAAAcAAJ&pg=PA465 |trans-title=On a new product from silica and potash; and its useful application as a protection against the rapid spread of fire in theaters, as a glue, varnish, etc. |language=German}}</ref>

The terms "water glass" and "soluble glass" were used by [[Leopold Wolff]] in 1846,<ref>{{cite book |last1=Wolff |first1=Leopold |title=Das Wasserglas: Seine Darstellung, Eigenschaften und seine mannichfache Anwendung in den technischen Gewerben |trans-title=Water-glass: its preparation, properties, and its manifold uses in technical commerce |date=1846 |publisher=Gottfried Basse |location=Quedlinburg and Leipzig, Germany |url=https://books.google.com/books?id=ajdkAAAAcAAJ |language=German}}</ref> by [[Emil Kopp|Émile Kopp]] in 1857,<ref>Emile Kopp (1857): "Sur la préparation et les propriétés du verre soluble ou des silicates de potasse et de soude; analyse de tous les travaux publiés jusqu'a ce jour sur ce sujet" (On the preparation and properties of soluble glass or the silicates of potash and soda; analysis of all works published until today on this subject). ''Le Moniteur scientifique'', volume 1, [https://books.google.com/books?id=zS5EAAAAYAAJ&pg=PA337 337–349], [https://books.google.com/books?id=zS5EAAAAYAAJ&pg=PA337 pages 366–391].</ref> and by [[Hermann Krätzer]] in 1887.<ref>{{cite book |last1=Krätzer |first1=Hermann |title=Wasserglas und Infusorienerde, deren Natur und Bedeutung für Industrie, Technik und die Gewerbe |trans-title=Water-glass and soluble earths, their nature and significance for industry, technology, and commerce |date=1887 |publisher=Hartleben |location=Vienna, Austria |url=https://books.google.com/books?id=CCZaAAAAYAAJ |language=German}}</ref>

In 1892, Rudolf Von Wagner distinguished [[soda glass|soda]], [[potash]], double (soda and potash), and fixing (i.e., stabilizing) as types of water glass. The fixing type was "a mixture of silica well saturated with potash water glass and a sodium silicate" used to stabilize inorganic water color pigments on cement work for outdoor signs and murals.<ref>Von Wagner, Rudolf (1892; translation of 13th edition by Willian Crookes) ''Manual of Chemical Technology'' [https://archive.org/details/manualchemicalt00croogoog]</ref><ref>Von Wagner, ''Manual of Chemical Technology'' (1892 translation)</ref><ref>Hermann Mayer (1925): ''Das Wasserglas; Sein Eigenschaften, Fabrikation und Verwendung auf Grund von Erfahrungen und Mitteilungen der Firma Henkel & Cie''. (The Water-glass: Its properties, production, and application on the basis of experiences and communications of the firm of Henkel & Co.) Published by Vieweg, Braunschweig, Germany.</ref><ref>Morris Schrero (1922): [https://archive.org/details/waterglassabibl00schrgoog/page/n2 <!-- pg=1 --> ''Water-glass: A Bibliography'']. Published by Carnegie Library, Pittsburgh, Pennsylvania.</ref>