Dr. Schlüter & Dr. Mass, 1924 - ca. 1944
Johannes Ernst Curt Schlüter, 1881 - 1944Dr. Schlüter & Mass, 1912 - 1924
Karl Heinrich Otto Mass 1876 - 1944
by Brian Stevenson
last updated October, 2021
The businesses of Curt Schlüter and Otto Mass produced large numbers of microscope slides between ca. 1912 and ca. 1944 (Figure 1). They also retailed microscopes, presumably manufactured by wholesale producers (Figure 2). Initially named "Dr. Schlüter and Mass", the name was modified in 1924 to reflect the Ph.D. that Otto Mass earned from the University of Frankfurt. Those firms, and their predecessors/successors also retailed a wide variety of scientific objects (Figures 3-6).
Figure 1.
Microscope slides from Dr. Schlüter & Mass (top, produced between 1912 and 1924) and Dr. Schlüter & Dr. Mass (bottom, produced between 1924 and ca. 1945). The glass of the top slide is substantially thicker than that of the later slide.
 
Figure 2.
Circa 1930s compound microscope that was retailed by Dr. Schlüter and Dr. Mass. It was undoubtedly brought in from a wholesale manufacturer. Adapted for nonprofit, educational purposes from an internet auction site.
 
Wilhelm Schlüter (1829-1919) established the "Naturalien- und Lehrmittelhandlung Wilhelm Schlüter" in Halle (Saale), Germany in 1853. This was reportedly the first commercial source of scientific and teaching materials in Germany. Management of the business passed to his son Willy Schlüter in 1894.
Otto Mass began as an apprentice with the Schlüter business in 1890. In 1907, he became a partner.
Willy's son, Curt Schlüter, studied at Friedrichs University of Halle and the University of Leipzig, earning a Ph.D. in zoology in 1911. Along with Otto Mass, he reorganized the business as "Dr. Schlüter and Mass" in 1912.
Curt Schlüter served in the German artillery during the First World War.
The business was renamed "Dr. Schlüter and Dr. Mass" in 1924, after Mass received a Ph.D. The firm's 1928 catalogue listed an extensive variety of microscope slides on topics ranging from botany to human physiology.
Otto Mass died on January 24, 1944, in Halle. His partner, Curt Schlüter, died soon afterward, on May 1, 1944, also in Halle.
After the Second World War, the Schlüter family moved to Winnenden, West Germany, and reorganized as "Schlüter Biologie". The business now operates as "Jörk Klawun - Schlüter Biologie", producing a variety of biology teaching materials, and located in Eutin, Germany.
Figure 3.
1921 advertisements by Dr. Schlüter and Mass, from "Naturwissenschaftlicher Beobacter".
 
Figure 4.
1929 advertisement from "The Naturalists' Directory"..
 
Figure 5.
Listing for Dr. Schlüter and Dr. Mass from the 1940 Halle telephone directory. Accessed through ancestry.com.
 
Figure 6.
Mounted skeleton of a toucan, prepared by Dr. Schlüter and Mass. Adapted for nonprofit, educational purposes from https://www.europeana.eu/en/item/52/gnm_photo_GNM5375_002
 
Figure 7.
Lantern slides of various subjects, by Dr. Schlüter and Dr. Mass. Adapted for nonprofit, educational purposes from an internet auction site.
 
Resources
Bracegirdle, Brian (1998) Microscopical Mounts and Mounters, Quekett Microscopical Club London, pages 32 and 168, and Plate 32-C
Death record of Johannes Ernst Curt Schlüter (1944) accessed through ancestry.com
Death record of Karl Heinrich Otto Mass (1944) accessed through ancestry.com
Dr. Schlüter & Dr. Mass, Naturwissenschaftliche Lehrmittel-Anstalt, Halle (Saale), Gegründet 1853 von Wilhelm Schlüter, Jubiläums-Katalog 290 über Biologie (1928) Gebauer-Schwetschke, Halle
Hirsch, G.C. (1928) Index Biologorum, J. Springer, Berlin, page 264, "Schlüter, Johannes Ernst Curt (1881) Dr. Phil., Zool., wissenschaftlicher Leiter der Naturwiss. Lehmittelanstalt von Dr. Schlüter und Dr. Mass, Halle a.d.S. (Deutschland), Viktoriastr. 9. Palaearktische Tenthrediniden. D Leipzig 1911. P Biol. Praep. und Modelle"
The Naturalists' Directory (1929) Advertisement, S.E. Cassino, Salem, Massachusetts
Naturwissenschaftlicher Beobacter (1921) Advertisements from Dr. Schlüter and Mass, Vol. 62, several issues
Rosenbauer, Karlheinz A. (2003) Mikroskopische Präparate, Vol. 1, John Wiley & Sons, pages 85-86
Schlüter Biologie (accessed October, 2021) http://www.schlueter-biologie.de