Written by: Mari Isa
Primary Source: Campus Archaeology Program Blog, December 6, 2016.
At Campus Archaeology, we often encounter laboratory glassware in contexts such as the veterinary and botanical laboratories, excavations near lab row, and even the Gunson assemblage. This is not surprising, as MSU has a long history of scientific research. However, the presence of lab glass presents us with some interesting challenges as we attempt to answer questions such as: what kind of equipment is this from? When is it from? What might it have been used for?
In order to begin identifying the large quantities of lab glass in our collections, it helps to understand what forms of glassware exist and what they are used for. Beakers and flasks are used to hold reagents for chemical reactions. Graduated cylinders are used for measuring the volume of samples. Retorts are used for distillation, pipettes for transferring fluids, condensers for cooling hot liquids or vapors, and so on. As we encounter distinctive pieces in our assemblages, we can compare their shapes and sizes to catalogs of laboratory glass to try to identify the type of equipment they came from.
Sometimes, the color or thickness of glass might help us identify its use. Dark brown or amber (actinic) glass might indicate a bottle used for chemical storage. Actinic glass is often used for storage purposes because it blocks ultraviolet and infrared radiation that causes chemical degradation. In contrast, laboratory glass used for experiments is colorless and transparent to allow for viewing of chemical reactions. Very thick, heavy-walled glass may indicate glass used in pressure reactions, while thin, flat glass tends to be used for more delicate objects such as microscope slides.
As I learned in my research, even the type of glass and its place of manufacture can provide some information about an artifact. Ideally, laboratory glass should be resistant to cracking due to thermal stress. When glass is heated or cooled rapidly, the temperature of the external surface changes more quickly than the internal surface. This causes unbalanced expansion of the glass, which can produce cracks. Early 19th century glassmakers addressed this problem by producing thin-walled glassware made of lime glass. Thinning the walls reduced the temperature differential between inner and outer surfaces, limiting the risk of cracks.
At the end of the 19th century, a German chemist named Otto Schott discovered a more elegant solution to the problem of thermal stress. Between 1887 and 1893, Schott and his associates Carl Zeiss and Ernst Abbe developed borosilicate glass, a type of glass composed of silica and boron trioxide that expands very little in the presence of heat. This heat-resistant property quickly made borosilicate, over lime glass, then the industry standard for laboratory glassware. Borosilicate glass was marketed as “Jena glass” after Jena, Germany, where it was developed.
The United States produced little of its own glassware in the 19th century. By 1902 at least one American company (Whitall Tatum & Co.) was also making borosilicate laboratory glass under the brand name of “Nonsol.” Several Whitall Tatum & Co. bottles with chemical names and formulas were recovered from the Gunson site. However, most American companies struggled to compete with German-made scientific glassware. It wasn’t until World War I when, economically cut off from Europe, America began to produce most of its own laboratory glass. A 1918 Bureau of Standards study of laboratory glassware showed five American brands of borosilicate glass (Macbeth-Evans, Pyrex, Nonsol, Fry, and Libbey) performed as well as German Jena Glass. All six borosilicate glass brands were more resistant to thermal shock than Kavalier, the most popular brand of lime glass.
Archival information on campus purchases of laboratory glassware is often limited. The archives do not always provide specifics about the types of laboratory glass that were being purchased or what they were used for. Sometimes, there are records that glass purchases were made—in the 1897 Minutes of the Meeting of the Board of Trustees, for example, the records show that the veterinarian requested $100 worth of “glassware—test tubes, etc.,” but no other information is provided. Photographs of students and faculty working in various laboratories across campus can provide more direct evidence as to the types of glassware used around campus. A photograph of the bacteriology laboratory in 1905 shows a collection of bell jars, petri dishes, test tubes, glass reagent bottles, a microscope (and, I presume, microscope slides), and a large Erlenmeyer flask. A 1914 photograph of students in the chemistry laboratory shows an array of clear reagent bottles with glass stoppers (some helpfully labeled “Alcohol” and “Acid Acetic”), volumetric flasks, an Erlenmeyer flask, and a graduated cylinder.
Sometimes we are lucky enough to come across lab glass with makers’ marks. A piece of a flask or beaker with the mark “Schott & Gen” recovered from the Gunson assemblage probably refers to Schott & Genossen, the glass manufacturing company founded by Otto Schott and associates. This tells us that this item was manufactured after 1887, and was probably imported from Germany, likely before World War I when American production of borosilicate glassware became more common.
Recent excavations have provided us with an abundance of laboratory glassware. As we encounter these artifacts in our laboratory, we will continue to use some of the strategies described here to identify them and connect them with activities on campus.
MSU Archives & Historical Collections. UA 1 State Board of Agriculture/Board of Trustee Records. Board of Trustee Meeting Minutes Notes: 1897
Jenson, WB. The Origin of Pyrex. J. Chem. Educ., 2006;83:692-693.
Walker PH and FA Smither. Comparative Tests of Chemical Glassware, Technological Papers of the Bureau of Standards, No. 107, Government Printing Office: Washington, DC, 1918.
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