"Chemistry is when it bangs and pongs,
Physics is when it always goes wrong"....
A saying that seems rather apt as you look at all the equipment that once stood in our lab. Because, of course, preparing medicines has a lot to do with chemistry.
In here, crucibles were heated over an open flame along with liquids in test tubes. You can see chillers required for distillation, where the liquid would be condensed. The first part of the showcase contains reaction vessels involved in heating, chilling and sterilisation. Right at the bottom is a large pressure cooker, an autoclave with a gas burner. This was used to sterilise objects, for example, or the contents of ampoules.
Another task performed in the lab involves separating wet substances from solids. The desiccators on show here were used to dry out chemical substances, while the manual centrifuge served to separate the components of suspensions, emulsions and gas mixtures. The spherical glass vessel with the long, sloping neck on a wrought-iron stand is a beautiful late 18th century retort. It’s an alembic, a simple type of still. Next to it is what’s known as a Florentine bottle, which would have been used to separate oils from water by decanting.
Another important task is determining physical parameters. They’re important when it comes to characterising, and hence examining, medicinal substances and raw materials. We have various instruments used to measure volume on display here, for instance measuring scales and measuring cylinders, as well as scales and weights used to determine mass.
The two-armed Mohr balance is something very special. It’s named after its inventor, Koblenz pharmacist Friedrich Karl Mohr, and it can be used to determine the density of liquids. A weight attached to a balance beam is immersed in the liquid to be examined. There are ten notches on the load arm, and riders are slotted into these as counterweights until equilibrium is achieved. From the position and size of the riders, the specific gravity of the liquid can be read off to three decimal places.
All depictions: © Trüpschuch