Eureka! A Laboratory Glass Makers Mark

We’ve been working our way through cataloging materials excavated during the summer 2015 field school. Last semester the interns, volunteers and I finished unit A. It contained an astounding 8,617 artifacts weighing 52.48 kilograms! As we’ve previously discussed, the Gunson assemblage is a mix of household (plates, cups, vases, condiment jars, bottles), personal (toiletries, cosmetics), building material (bricks, nails, knob and tube electrical, lightbulbs), and laboratory equipment. The laboratory equipment has presented us with a puzzle.

Students in chemistry lab circa 1895 - source: MSU Archives
Students in chemistry lab circa 1895 – source: MSU Archives

Its presence isn’t completely unusual or unexpected. CAP has encountered laboratory glass during previous excavations, especially near lab row and the veterinary laboratory. The Gunson residence has an attached experimental greenhouse, so we’re working under the assumption that the laboratory glass is from that part of the structure. According to the 1924 remodel blueprints, the greenhouse was also altered and perhaps old or broken laboratory equipment was disposed of at that time. Intern Jasmine Smith is working on a project to create a laboratory glass guide based on the wide range of objects from the Gunson assemblage.

Thus far we’ve found pieces of test tubes, flasks, beakers, graduated cylinders, stir sticks, and lighting. However it wasn’t until this week that we located a glass fragment with a makers mark.

Schott & Gen Lab Glass Fragment
Schott & Gen Lab Glass Fragment

This fragment has the label “Schott & Gen 800”. This is most likely an 800 ml flask or beaker produced by Schott & Genossen. Glastechinsches Laboratorium Schott und Genossen, later the Jenaer Glasswerk Schott & Gen was founded in 1884 by Otto Schott, Ernse Abbe, Carl Zeiss and Roderick Zeiss. Schott’s glass was manufactured with silica and boron oxide made it ideal for beakers and test tubes.

Complete Schott Florence Flask - source
Complete Schott Florence Flask – source

Their unique manufacturing process made the glass resistant to chemicals, high heat, and sudden fluctuations in temperature.   Schott & Genossen were the preeminent producer of laboratory glass until WWI. After WWII the copy was split, with a production factory in both East and West Berlin. Following the fall of the Berlin Wall in 1989 the company regrouped.   The Schott group is still in production, makings its 125th anniversary in 2009.

In the 1910s the company realized that the same attributes that made the glass good for science, also made it ideal for housewares. Schott’s son connected with Bauhaus designers to create housewares, most notably teacups and pitchers. These Bauhaus era (1930s) production pieces are highly collectible, and often found in modern art museums ( (

We’ve only just begun examining artifacts from unit D (the labeled glass came from unit 2), so hopefully moving forward we will find more identifiable portions of laboratory glass.

Author: Lisa Bright


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