Galileo had observed vibrational patterns in a brass plate as early as 1638. See: Galilei, Galileo; Crew, Henry and de Salvio, Alfonso, trans. (first published in Italian 1638; 1914) Dialogues Concerning Two New Sciences New York City, New York, US: Macmillan Co. pp. 101–102. From p. 100: "As I was scraping a brass plate with a sharp iron chisel in order to remove some spots from it and was running the chisel rather rapidly over it, I once or twice, during many strokes, heard the plate emit a rather strong and clear whistling sound; on looking at the plate more carefully, I noticed a long row of fine streaks parallel and equidistant from one another."
McCoy, T. J.; Steele, I. M.; Keil, K.; Leonard, B. F.; Endress, M. (1993). "Chladniite: A New Mineral Honoring the Father of Meteoritics". Meteoritics. 28 (3): 394. Bibcode:1993Metic..28Q.394M.
McCoy, T.J.; Steele, I.M.; Keil, K.; Leonard, B.F.; Endreβ, M. (1994). "Chladniite, Na2CaMg7(PO4)6: A new mineral from the Carlton (IIICD) iron meteorite". American Mineralogist. 79: 375–380. Bibcode:1994AmMin..79..375M.
Chladni, Ernst Florens Friedrich, Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen und über einige damit in Verbindung stehende Naturerscheinungen [On the origin of the iron masses found by Pallas and others similar to it, and on some natural phenomena associated with them] (Riga, Latvia: Johann Friedrich Hartknoch, 1794). Available on-line at: Saxon State and University Library at Dresden, Germany.
J. Michael McBride, "Chladni Figures and One-Electron Atoms", Lecture #9, Freshman Organic Chemistry (CHEM 125) course, Open Yale Courses, Yale University, video recorded Fall 2008, accessed on YouTube, https://www.youtube.com/watch?v=5kYLE8GhAuE, 5 June 2016.