The Science of Discworld, the Middle Ages, and hands-on experiments for a 15‑year‑old

This guide links the ideas in The Science of Discworld (which alternates fictional stories and real science) to real medieval metalworking and simple, safe experiments you can do with Mel chemistry kits (corrosion kit and chemistry & electricity kit). I explain the science step by step, give historical context, and list several supervised experiments you can do to see corrosion and simple electrochemistry in action.

1. A short historical note: science in the Middle Ages

In the Middle Ages (roughly 500–1500 CE) there wasn’t modern chemistry, but there was a lot of practical knowledge: blacksmiths, armorers, miners, and apothecaries developed techniques by trial and craft. They smelted ores, hammered and annealed iron, coated metal to protect it (oiling, tinning, painting), and understood that certain processes made tools last longer—even if they didn’t describe it in modern chemical terms. Alchemy mixed mystical ideas with practical lab methods; later the scientific method and chemistry built on those practical roots.

2. What is corrosion? The basic chemistry (simple)

Corrosion is when a metal reacts chemically with its environment and changes into a different material. The most familiar form is rust: iron reacting with oxygen and water to make iron oxides (the reddish flaky stuff). In simple terms:

• Iron + Water + Oxygen → Iron oxide (rust)

Chemically, corrosion is often an oxidation reaction (the metal loses electrons). If two different metals touch in a wet salty environment, one metal will corrode faster (galvanic corrosion) because of differences in their tendency to lose electrons (the reactivity series).

3. How medieval people reduced corrosion

• Physical barriers: oil, wax, paint, and tar to keep water and air away.
• Coatings: tin-plating iron (making tinplate), or using more corrosion-resistant metals like bronze for items exposed to weather.
• Design: draining water away or avoiding trapped moisture.

These are the same basic ideas you will test with the kits.

4. Safety first (important)

• Always wear safety goggles and gloves when doing chemistry or electricity experiments.
• Work in a well-ventilated area and keep long hair tied back.
• Follow the Mel kit instructions and have a responsible adult help with any steps that involve acids, electrical connections, or heating.
• Do not ingest chemicals. Dispose of liquids and solids as the kit instructs (or dilute and neutralize where appropriate under supervision).

5. Experiments you can do (step-by-step)

Experiment A — Fast rusting: steel wool in vinegar vs water

What you’ll learn: how acid speeds corrosion by removing protective coatings and accelerating oxidation.

Materials: Mel corrosion kit (or steel wool), white vinegar, tap water, two clear jars, tongs, gloves, goggles.

1. Put on goggles and gloves.
2. Take equal small pads of steel wool (about 1–2 g each). Gently remove any protective oil if present by rinsing one pad in water and the other leave as-is for comparison.
3. Place one pad in a jar of plain water and one in a jar of vinegar. Close jars or cover them to reduce splashes.
4. Leave them for several hours to a day. Check and photograph every few hours.
5. Observe: the vinegar sample should show rust or a faster breakdown of the steel wool than plain water.

Why it happens: acetic acid (vinegar) speeds the oxidation of iron and removes thin protective films, so iron loses electrons faster and forms rust more quickly.

Experiment B — Copper patina (greenish layer) with salt and vinegar

What you’ll learn: how different metals form different corrosion products; copper forms a stable patina (basic copper salts) rather than flaky rust.

Materials: piece of copper (wire or strip), vinegar, table salt, shallow dish, gloves, goggles.

1. Wear goggles and gloves.
2. Make a solution of about 1 part salt to 3 parts vinegar in the dish and stir until salt dissolves.
3. Soak the copper piece for a few hours or leave it overnight.
4. Observe the colour change (green/blue patina on copper).

Why it happens: copper reacts to form copper salts (patina). This can actually protect the underlying copper in many cases—unlike flaky iron rust.

Experiment C — Simple voltaic cell (light an LED or measure voltage)

What you’ll learn: how two different metals plus an electrolyte make electricity (basic electrochemistry).

Materials: Mel chemistry & electricity kit pieces: copper strip, zinc strip (or galvanized nail), small container, salt or vinegar electrolyte, wires, small LED or multimeter, alligator clips, goggles.

1. Wear goggles. Set up on a non-conductive surface.
2. Fill the container with saltwater or diluted vinegar (the electrolyte).
3. Place the copper and zinc strips into the solution without them touching. Connect the copper to the LED's positive lead and zinc to the LED's negative lead with alligator clips and wires (or measure voltage with a multimeter).
4. If the LED is very small (low current) it may light faintly; a voltmeter should show a voltage (around 0.8–1.1 V for a single copper–zinc cell depending on conditions).

Why it works: different metals have different tendencies to lose electrons. The zinc oxidizes (loses electrons) and the copper acts as the positive electrode; electrons flow through the wire powering the LED.

Experiment D — Galvanic corrosion demo (copper + iron in saltwater)

What you’ll learn: how connecting two different metals can make one corrode faster (use this to understand why medieval craftsmen chose certain metal pairings carefully).

Materials: small steel nail, copper wire, saltwater, container, connecting wire, goggles, gloves.

1. Wear safety gear.
2. Place the steel nail and the copper wire in saltwater. Connect them with a wire so they form a metal-to-metal connection (or just have them touch).
3. Leave for many hours to days and observe the steel nail for accelerated rusting near the connection point compared to a control nail alone in the same water.

Why: the less noble metal (iron) becomes the anode and corrodes faster. This is why mixing metals in contact in wet environments can cause problems (important for ships, armor, and tools).

Experiment E — Electroplating (optional, supervised)

What you’ll learn: how electricity can deposit metal ions onto another object (used historically for coating important objects after the medieval period).

Note: electroplating requires careful handling of solutions and currents. Only do with adult supervision and following kit instructions.

Basic idea: dissolve a plating metal salt or use a metal electrode in an electrolyte, connect the object as the cathode and the metal as the anode, and let the current deposit metal onto the object.

6. Observations and connecting to The Science of Discworld

Take notes and pictures for each experiment: what changed, how quickly, and where the changes happened. In The Science of Discworld, the authors contrast myth and stories with the actual methods of science. These experiments are the same kind of empirical observations medieval craftsmen used—only now you can explain them with modern chemistry (oxidation, electrons, electrolytes).

7. Cleanup and disposal

• Neutralize acidic solutions (small amounts) by diluting with lots of water before disposing down the sink if local rules allow. Better: follow kit disposal instructions or have an adult help with proper hazardous-waste disposal.
• Collect metal scraps and dispose or recycle them properly—don’t throw reactive metals in ordinary trash.
• Wash hands thoroughly after experiments.

8. Further reading and ideas

• Reread the non-fiction chapters of The Science of Discworld to see how storytelling and science interact.
• Research medieval techniques: blacksmithing, tinning, and armor care—compare what craftsmen did with what your experiments show.
• Try varying one factor at a time (salt concentration, acidity, contact/no contact between metals) and record results—this is how controlled experiments work.

If you want, tell me which Mel kit experiments you have materials and instructions for, and I can give a custom step-by-step version that matches your kit exactly (including exact solution concentrations and safety notes).

Have fun, be careful, and remember: hands-on experiments are exactly how medieval craftsmen learned—then science gave us the explanations.