Test tubes, conical flasks, beakers and beyond—laboratory glassware is one of the most iconic symbols of chemistry.
Thanks to its use by the alchemists, in the words of chemistry historian Marco Beretta:
Glass was destined to become the protagonist in the modern chemical laboratory.
Read on to discover the many properties of glass which make it essential to a chemist's work, and the wide range of functions it can serve.
Glassmaking: An ancient technology
Glassmaking is a very old technology—there are glass artefacts found in Syria that are 4,500 years old.
One hypothesis is that the process of making glass was discovered as a by-product of the practice of metallurgy—the science of extracting metals from their ores at high temperatures. These ores are found in rocks, which are often made from silicates, just like glass.
Copper smelting, for example, has been dated back 8,000 years to what is now modern Turkey. Copper could be extracted from malachite at temperatures of around 1,200 degrees centigrade, with charcoal acting as a reducing agent.
To separate ore from rock, a flux such as sodium carbonate or potassium carbonate was also added. This resulted in a mixture of molten metal and a waste layer of flux and melted rock, known as slag.
The layers of slag and molten metal are immiscible: the metal layer is denser and the lighter slag layer can be separated off. When the slag cools, the result is a glassy solid.
Perhaps the ancients saw a potential new wonder material in this slag waste.
Seth Rasmussen has argued that this hypothesis is supported by archaeological finds: the tools for making both bronze and glass ingots were found at the same Ramesside Egyptian site of Qantir.
Early scientific glassware
The alchemist Maria Hebraica, who lived in the first century, is credited with the invention of distillation apparatus. Stills are used to purify liquids, and are thought to be the oldest use of glass in the laboratory.
Stills have three elements: the cucurbit, the ambix (alembic) and bikos. The impure starting liquid is heated in the cucurbit, where different components of liquid mixture will evaporate at different temperatures.
At varying temperatures, these different components of the starting liquid will condense in the ambix and trickle down into the bikos to be collected as separate fractions.
Seth Rasmussen points to several important characteristics of glassware which make it ideal for use in the laboratory.
The starting materials for glass, sand and sodium carbonate, are cheap and abundant. But glass is also durable, transparent and versatile.
Rasmussen suggests that glass could only be applied reliably in laboratory apparatus from the 13th century onwards. It was during this time that glassmakers in Venice and Murano found new processes for improving the thermal and chemical resistance—the durability—of glass, by using more calcium, magnesium and potassium salts in the mixture.
Alongside this ability to withstand high temperatures and strong chemicals, transparency is a key advantage of glass for experimentation.
Glass allows you to observe a reaction as it progresses. Imagine doing the classic school titration experiment with phenolphthalein indicator without transparent containers. Indeed, Marco Beretta has shown that Maria Hebraica appreciated glassware as it allowed the alchemist to "see without touching".
When doing something that has never been done before, you might need to make bespoke apparatus. Glass lends itself to this as it’s very versatile—it can be refashioned and shaped with relative ease.
University chemistry departments sometimes have glass-blowing workshops on site. Some chemists, like Bertram Lambert (1881–1963), are even expert glassblowers themselves.
The many lives of glassware
The protagonist of the laboratory is so ubiquitous it can be hard to trace the history of individual pieces—at a conservative estimate, we have at least 2,000 items of laboratory glassware in our collection.
Sometimes we are left clues. One such item is this one-litre glass bottle with a ground glass stopper. It would have been used to store solutions—not a glamorous but an essential function.
Like many pieces of laboratory glassware, it passed through multiple hands. More is known of its history than other items because its previous users etched their names onto the bottle: Jill Hermon, David Shorter, and Terry Wass and Sheila Fowler, who encircled their names in a love heart. The bottle is unique because of the window it opens onto the lives of the real chemists who used it.
Glassware may have many users and indeed many lives, as glass can be refashioned. In the early 20th century, Alexander Barclay, then curator of our chemistry collections, deaccessioned items of glassware so that he could use them in chemistry demonstrations.
Take, for example, these three glass washer bottles. They are the mid-19th century equivalent of the plastic wash bottles used in laboratories today. Different solvents—in this case water, alcohol and ether—will dissolve different residues from glassware in order to clean it, ready for use again.
The three wash bottles were displayed in an exhibition that drew over a quarter of a million visitors in August 1876, an exhibition that helped catalyse the formation of a Science Museum separate from the Victoria and Albert Museum.
In the early 20th century, these bottles were viewed differently by the museum: they were ubiquitous objects that could be easily replaced. Barclay, a practising chemist as well as curator, removed the wash bottles from the museum's collections in order to use them for their original purpose.
A century later, these types of mid-19th century wash bottle are not as common as they were. Now they are of interest to historians of science.
The wash bottles are also some of the founding objects of our science collection—they're part of the museum’s origin story, and in 2018 they were accessioned back into our permanent collection.
From practical use to museum display and historical research—the protagonist of the laboratory has taken many shapes and can have many lives.
Find out more
- Marco Beretta, 'Between Nature and Technology: Glass in Ancient Chemical Philosophy' in When Glass Matters: Studies in the History of Science and Art from Graeco-Roman Antiquity to Early Modern Era, 2004
- Seth C Rasmussen, How Glass Changed the World: The History and Chemistry of Glass from Antiquity to the 13th Century, 2012
- Britannica, History of metallurgy
- Wellcome Collection, The art of scientific glassblowing
- Smithsonian, Inventing American laboratory glass
- Compound Interest, Visual guide to laboratory glass
- Connecticut Public Radio, A scientific glassblower at Yale explains the art of his craft