Geissler, Johann Heinrich Wilhelm

(b Igelshieb, Thuringia, Germany, 26 January 1879)

glassnaking, technology.

Geissler’s father, Johann Georg Jacob Geissler, was a maker of glass beads and a burgomaster. His mother, Johanne Rosine Eichhorn, was the daughter of a glassmaker. He was descended from other craftsmen active in the Thüringer Wald and in Böhmen, and two of his brothers worked as mechanicians, one in Berlin and the other in Amsterdam. Comparatively little is known of Geissler’s life. He began working while very young and, having learned glassblowing in the duchy of Saxe-Meiningen, he practiced this trade at several universities, including Munich. He is said to have worked in the Netherlands for some eight years; he settled at The Hague in 1839 and is on census rolls of 1845 but not of 1849, although his workshop in Bonn is said to have been founded by him in 1841. In that year his brother, Friedrich Wilhelm Florenz, went to Amsterdam and made glass for the Gymnasium Illustre, especially for the physicist V. S. van der Willigen.

Geissler finally settled as a mechanic at the University of Bonn in 1852 (or earlier) and established a workshop for producing chemical and physical instruments. He provided many instruments for the mechanician W. H. Theodor Meyer and the physicist Julius Plücker, as well as for the mineralogist H. P. J. Vogelsang and the physiologist Eduard Pflüger. Later he was associated with Franz Müller, who succeeded him as owner of the workshop. On the fiftieth anniversary of the University of Bonn in 1868 he was awarded an honorary doctorate for his work.

Talented both in making instruments and in comprehending their physical bases, Geissler learned much from his association with the scientists at the university. He became an indispensable participant in the experimental work that was being conducted there.

The first account of Geissler’s activity dates from 1852, when, with Julius Plücker, at Bonn, he constructed his famous structed his famous standard thermometers. They differed from the thermometers then in use by their thin glass, by the application of capillarity, and by their high precision. For calibrating he used his new glass balance that had a sensitivity of 0.1 mg. of mercury. In 1863 Geissler constructed a maximum thermometer based on Casella’s minimum thermometers. Also in 1852 Geissler, at the invitation of a Bonn industrialist, constructed an instrument for measuring the alcoholic strength of wine. This “vaporimeter” measured the pressure of vapors of alcohol and air against mercury. Plücker improved the apparatus by eliminating the air and was thus stimulated to investigate vapors scientifically. Geissler also used the instrument to measure the strength of liquid ammonia.

In 1858 it was stated that Plücker relied on Geissler’s dexterity in using “Geissler’s tubes,” as Plücker called them—although, according to Plücker, Geissler was not the first to make such tubes. Geissler, in turn, stated in 1858 that he had made such tubes since 1857 and had sent many of them to Daniel Rühmkorff in Paris and to Bence Jones in London. There is a second invention connected with these tubes. The difficulty in obtaining a vacuum with the piston pumps then in use caused Geissler to construct a mercury air pump about 1855. Demonstrated to a wider public in 1858, it was an improvement on the idea of using Torricelli’s vacuum for evacuation, which the theosopher Emanuel Swedenborg had described in 1722 and many others after him had tried to use. Geissler’s pump, entirely of glass and thick rubber, was operated by manually moving a second tube up and down and therefore was slow, though effective.

Through use of this pump and his aptitude for glassblowing, Geissler was able to make rather small glass tubes with electrodes melted into the ends and filled with rarefied gases. By using these tubes Plücker was able to study discharges in very rarefied gases. The new and most interesting phenomenon, the stripes in the discharge light (Schichtung im elekreischenLicht), previously observed in the “electrical egg” by Rühmkorff and Jean Quet, could now, by means of “Geissler’s tubes,” be studied in detail. These tubes provided a much better vacuum and, in contrast with the “electrical egg,” were not dependent on a pump. (John Gassiot had already tried to produce such a vacuum, and in 1856 V. S. van der Willigen had obtained the phenomenon using tubes constructed by Geissler’s brother in Amsterdam.) At the thirty-ninth meeting of the Deutsche Naturforscher und Ärzte, held at Giessen in 1864, Geissler demonstrated his mercury pump; “Geissler’s tubes” were shown there in experiments by J. C. Poggendorff to demonstrate induced currents. On the whole, the technology of “Geissler’s tubes” helped to introduce a new branch of physics which led directly to the discovery of the cathode rays.

In addition, the thermometer tubes enabled Geissler to construct in 1852 an instrument for measuring the expansion of freezing water and ice. In 1858 Geissler suggested to Justus von Liebig that the chemical nature of gases could be identified by means of the discharge in “Geissler’s tubes”; this was further implemented by Vogelsang and Geissler in 1868, when they described a vacuum tube in which liquids occluded in minerals could be identified chemically by means of the then new technique of spectral analysis. About 1860, in the inner of these tubes, Geissler converted white phosphorus into the red form “by electricity,” as he put it. In 1873 he demonstrated the phenomenon before Anton von Schrötter at the world exhibition in Vienna, where he was awarded the Golden Cross of Merit in Art and Science.

BIBLIOGRAPHY

Descriptions of Geissler’s work, by himself and his collaborators, are in Annalen der Physik und Chemie, 162 (1852), 233–279; 168 (1854), 199–200; 179 (1858), 88–106; 199 (1864) 657–658; 201 (1865), 153–158; 202 (1865), 222, 227; 211 (1868), 332–335; and 228 (1874), 171–173; and “Sitzungsberichte der Niederrheinischen Gesellschaft für Natur- und Heilkunde zu Bonn,” in Verhandlungen des naturhistorischen Vereines der preussischen Rheinlande und Westfalens, 23 (Bonn, 1866) 12–14; W. H. T. Meyer, Beobachtungen über das geschichtete electrische Licht (Berlin, 1858).

There is an undated letter to an unknown correspondent in the Staatsbibliothek Preussischer Kulturbesitz, Berlin. Three letters to R. A. C. E. Erlenmeyer, dated 14 Jan. 1869, 9 June 1870, and 24 Mar. 1871, are in the Deutsches Museum, Munich. In the Bayerische Staatsbibliothek, Munich, are two letters to Justus von Liebig, one without date and one dated 2 Feb. 1858.

On Geissler’s life and work, see also Amtlicher Bericht über die 39. Versammlung Deutscher Naturforscher und Ärzte in Giessen im September 1864 (Giessen, 1865), pp. 81–86; Amtlicher Bericht über die Wiener Weltausstellung im Jahre 1873, 3 vols. (Brunswick, 1874–1875), II, 504 and III, 1, 221; Bericht über das fünfzigjährige Jubilaeum der Rheinischen Friedrich-Wilhelms-Universitât (Bonn, 1868); Dr. H. Geissler’s Nachfolger, Gedenkblatt zur Erinnerung an Heinrich Geissler, Dr. phil., Glastechniker…, zur Feier des 50 jâhrigen Bestehens der Firma seinen Freunden mit beigeheftetem Bildnisse gewidmet (Bonn, 1890); A. W. von Hofmann, in Berichte der Deutschen chemischen Gesellschaft, 12 (1879), 147–148; W. Huschke, Forschungen über die Herkunft der Thüringischen Unternehmerschicht des 19. Jahrhunderts, supp. 2 to Tradition (Baden-Baden, 1962), 34–35; H. Schimank, in Lichttechnik (Berling) 6 (1954), 364; and in Technikgeschichte in Einzeldarstellungen, 19 (1971), 37–38; and A. Wissner, in Neue deutsche Biographie, VI (Berling, 1964), 59.

Hans Kangro