Early Spectroscopy and the Balmer Lines of Hydrogen (the author

Mar 3, 2005 - Retcofsky's letter contains the assertion that Alter was the first to describe the Balmer lines of hydrogen in 1855. Perhaps this statem...
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Letters Early Spectroscopy and the Balmer Lines of Hydrogen Interesting though the comments of H. L. Retcofsky (1) regarding David Alter and his alleged priority in discovering spectrum analysis are, they comprise at least one point where there is a need for setting the record straight. Retcofsky’s letter contains the assertion that Alter was the first to describe the Balmer lines of hydrogen in 1855. Perhaps this statement was inferred from a similar remark in Hodge’s biographical paper (2). However, there is no doubt (3, 4) that the Balmer lines were already discovered by Ångström in 1853 (5). To complement what has been said in ref 1 about Alter’s work on the spectral lines of brass, it might furthermore be pointed out that Ångström in ref 5 also dealt with the observation that the spectrum of an alloy of two metals contains the spectrum of each of the constituents (6). Literature Cited 1. 2. 3. 4.

Retcofsky, H. L. J. Chem. Educ. 2003, 80, 1003. Hodge, E. S. Appl. Optics 1976, 15, 1722–1725. Schawlow, A. L. Rev. Mod. Phys. 1982, 54, 697–707. Pais, A. Inward Bound; Oxford University Press: New York, 1986; p 166. 5. Ångström, A. J. Kongl. Svensk. Vetenskapsakad. Handlingar 1852, 333–360. (Translations: Phil. Mag. 1855, 9, 327–342; Ann. Phys. 1855, 94, 141–165.) 6. Maier, C. L. in Dictionary of Scientific Biography, Vol. I; Scribner’s Sons: New York, 1970; pp 166–167. H. J. Wagner Theoretische Physik Universität Paderborn Pohlweg 55 33098 Paderborn, Germany [email protected]

The author replies: H. J. Wagner expresses concerns about my Letter in this Journal regarding the origin of spectrum analysis (1). As stated in my letter “there is considerable evidence that spectrum analysis actually had its origin in Western Pennsylvania”. Wagner, however, refers to the priority I assigned to David Alter with respect to spectrum analysis as “alleged”. In support of my view, I cited Alter’s work (2, 3) whose publications on the subject preceded that of Kirchoff and Bunsen (4) by approximately five years. That fact is indisputable! It is interesting that the work of Ångström (5),1 as referenced by Wagner, also predates that of Kirchoff and Bunsen. In his Nobel Prize address, Schawlow stated “Scientific Spectroscopy really began in Uppsala, Sweden, where Anders Ångström in 1853 showed that some of the lines in the spectrum of an electric spark come from the metal electrodes and others from the gas between them.” (6). Thus, concerns over claims such as the one described in my letter are not new to science. Furthermore, one needs only to read about the recent issues concerning the 2003 Nobel Prize in Physiology or Medicine to conclude that such controversies are not restricted to early discoveries in science (7). As to the other two points in Wagner’s response, both Alter and Ångström showed that the spectra of alloys consist of the spectra of the individual constituents. Alter demonstrated this in 1854 in the case of brass (2) whereas Ångström demonstrated it in 1852 in the case of a tin–lead alloy (5). Regarding the first observation of the Balmer lines of hydrogen, I stand corrected and am indebted to Wagner for pointing out the error. Note 1. Ångström’s original article is in Swedish. My reference 5 is an English translation.

Literature Cited 1. 2. 3. 4. 5. 6. 7.

Retcofsky, H. L. J. Chem. Educ. 2003, 80, 1003. Alter, D. Am. J. Sci. Arts 1854, 18, 55–57. Alter, D. Am. J. Sci. Arts 1855, 19, 213–214. Kirchhoff, G. R.; Bunsen, R. Ann. Phys. 1860, 110, 160. Ångström, A. J. Phil. Mag. 1855, 9, 327–342. Schawlow, A. L. Rev. Mod. Phys. 1982, 54, 697–707. Henry, C. M. Chem. Eng. News 2003, 81 (44), 39–40. H. L. Retcofsky Spectroscopy Society of Pittsburgh South Park, PA 15129-8977 [email protected]

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