‎"KIRCHHOFF, G. und R. BUNSEN. - FOUNDING SPECTRUM ANALYSIS.‎
‎Chemische Analyse durch Spectralbeobachtungen. (Erste-) Zweite Abhandlung. (2 Papers).‎

‎Leipzig, Johann Ambrosius Barth, 1860, 1861. 2 uniform contemp. hcalf, raised bands, gilt spine. A few scratches to spine. In ""Annalen der Physik und Chemie. Hrsg. von J.C. Poggendorff"", Bd. 110 a. Bd. 113. - IX,668 pp. a. 8 folded plates. X,660 a. 8 folded plates. Entire volumes offered. The 2 papers: pp. 161-189 a. pp. 337-381 and plates (one plate in chromolithography, spectra of different elements). Verso of titlepages and verso of plates with small stamps. Internally fine and clean.‎

Reference : 43086

‎First printing of these fundamental papers, constituting the invention of Spectrum Analysis and announcing the discovery of two new elements, Cesium and Rubidium by using the new method of spectroscopy developed by them. This technique, made possible by their invention of the spectroscope is called ""One of the most dashing advances of the human mind into the secrets of the composition of matter on earth and in cosmos""(Kedrow in ""Spectralanalyse"", 1961). The spectral lines proved to be a guide not only to the great world of the outer cosmos, but to the infra-tiny world within the atom. Balmer made the first steps in this direction (the Balmer-lines).""The two investigators advanced, as scientifically established, the law that the bright lines in the spectrum may be taken as a sure sign of the presence of the respective metals. This conclusion was rendered doubtly sure by the discovery in the mineral water of Durkheim, through the spectrum, of two new metals. From the blue and the red lines, by which they were recognized, they were named ""Cæsium"" and ""Rubidium"". While spectrum analysis, as a terrestrial science, was due equally to Kirchhoff and Bunsen, its celestial applications belong to Kirchhoff alone.""(Cajori in ""A History of Physics in its Elementary Branches"", pp. 160 ff).In a letter to Henry Roscoe, with whom Bunsen carried out a long importent series of photochemical researches, Bunsen wrote: ""At present Kirchhoff and I are engaged in a common work which doesn't let us sleep....Kirchhoff has made a wonderful, entirely unexpected discovery in finding the cause of the dark lines in the solar spectrum, and increasing them artificially in the sun's spectrum, and inproducing them in spectra which does not have lines, and in exactly the same position as the corresponding Frauenhofer lines. Thus a means has been found to determine the composition of the sun and fixed stars with the same accuracy as we determine sulfuric acid, chlorine, etc., with our chemical reagents. Substances on the earth can be determined by this method just as easely as on the sun, so that, for example, I have been able to detect lithium in twenty grams of sea water.""‎