18th- and 19th-Century Scottish Laboratory Glass: Assessment of Chemical Composition in Relation to Form and Function

Glassware used in the laboratories at the University of Edinburgh in the 18th and 19th centuries was analyzed using portable X-ray fluorescence. The samples came from two sources: the Playfair Collection, an assortment of vessels and equipment currently in the care of the National Museums Scotland, and excavations at the university's Old College Quadrangle. A high degree of commonality was observed between the Playfair and quadrangle samples. High-lead glasses contained over 30-percent lead oxide, along with small amounts of arsenic and potassium. High calcium glasses contained over 20-percent calcium, alongside magnesium, aluminum, strontium, iron, titanium, and sulfur. Moderate-lead glasses contained less than 25-percent lead and also strontium and iron, which were not observed in the high-lead glasses, indicating that cullet from another glass type may have been used in their manufacture. High levels of lead were found in items that require thermal stability and a high degree of transparency. High levels of calcium were seen in vessels that may have been used to hold and store chemicals, requiring a high degree of chemical stability. These items suggest that Scottish glassmakers were capable of producing high-quality items of a relatively uncommon nature, using unusual ingredients in the melt.