Historical figure · Pearson Edexcel International GCSE revision on Incandio

Robert Boyle

Who Emptied a Jar and Silenced a Bell · Natural Philosopher & Chemist · 1627–1691

The wealthy experimenter who built the best air pump in Europe, used it to show that sound needs air and light does not, found that a gas's volume falls as its pressure rises, and insisted that experiments be published in full — failures included.

Defend these ideas against Boyle

Incandio is a free revision platform for the Pearson Edexcel International GCSE, and on it a topic counts as mastered only once you have learned it, proved it in questions, taught it back and defended it against the person with the strongest claim on it. Robert Boyle is that person for 6 topics on the course:

• Weight and Terminal Velocity — Physics
• Acids, Alkalis and the pH Scale — Chemistry
• Preparing a Soluble Salt — Chemistry
• Sound Waves — Physics
• The Gas Laws — Physics
• Direct & Inverse Proportion — Mathematics

Who was Boyle?

Robert Boyle was the fourteenth child of the Earl of Cork and rich enough to spend his life doing exactly as he pleased, which was experimenting. With Robert Hooke as his assistant he built an air pump finer than any then existing and used it to evacuate a glass receiver and see what followed. A candle went out; a bird died; and a bell set ringing inside the vessel grew fainter until nothing could be heard at all, though it could plainly be seen to ring — sound needs a medium and light does not. Trapping air in the short arm of a J-shaped tube and pouring in mercury, he found that the volume of a gas varies inversely with the pressure upon it, the relationship that carries his name. In The Sceptical Chymist of 1661 he attacked both the four elements of Aristotle and the three principles of the alchemists, arguing that a substance should be called an element only if it cannot be decomposed further. He was a founding member of the Royal Society, and he set its standard for reporting: describe the apparatus and the procedure in full, and publish the attempts that failed, because a reader who cannot see the whole cannot judge any of it. He practised alchemy throughout his life and believed transmutation possible.

Major achievements

• Built, with Hooke, the finest air pump in Europe
• Showed that sound requires a medium and does not travel through a vacuum
• Established that the volume of a gas varies inversely with its pressure
• Wrote The Sceptical Chymist, attacking the four elements and alchemical principles
• Defined an element as a substance that cannot be decomposed further

Life in brief

• 1627 — Born at Lismore Castle: Fourteenth child of the Earl of Cork.
• 1655 — Settles at Oxford: Takes on Robert Hooke as his assistant.
• 1659 — The air pump: Built by Hooke; the finest instrument of its kind.
• 1660 — New Experiments: The candle, the bird and the silenced bell in the evacuated receiver.
• 1661 — The Sceptical Chymist: An attack on the four elements and the alchemists' principles.
• 1662 — Boyle's law: Volume varies inversely with pressure, from the J-shaped tube.
• 1663 — The Royal Society: A founding member, and the setter of its reporting standard.
• 1691 — Dies in London: A week after his sister Katherine.

Explore the life of Boyle — five chapters

1. The Fourteenth Child of the Richest Man in Ireland — Money, and what it bought
2. The Bell That Could Be Seen and Not Heard — The air pump, and what happens when the air goes
3. The J-Shaped Tube — Volume against pressure, 1662
4. The Sceptical Chymist — Attacking both sides at once
5. Publish the Failures — The reporting standard, and a quiet death

Read the five-chapter life of Robert Boyle →

Where Boyle appears in your course

Robert Boyle has a genuine claim on 12 lessons of the Pearson Edexcel International GCSE science course built into Incandio. Six of them:

• Concentration and Gas Volumes — Chemistry: The molar volume comes with a condition attached — 24 dm³ at room temperature and pressure, and a different figure otherwise — and Boyle is the person who established that a gas's volume depends on the pressure upon it at all. Trapping air in the short arm of a J-shaped tube and pouring in mercury, he found that the volume falls as the pressure rises, in inverse proportion. He is also the right figure for the picture behind this page, since his air-pump work is what established that a gas is mostly empty space, and he published his failures alongside his successes so that anyone could repeat the measurement.
• Simple Molecular Substances — Chemistry: This page rests on molecules being separate and far apart in a gas, and Boyle is the person who first established that experimentally. Trapping air in the short arm of a J-shaped tube and pouring in mercury, he found the volume falls as the pressure rises — which is only possible if a gas is mostly empty space with something small distributed through it. His air-pump work made the same point from the other end: a candle goes out, a bell falls silent, and yet the vessel is not truly nothing. He is also the right person for the caution on this page, since he insisted on publishing procedures in full so that others could check them.
• Acids, Alkalis and the pH Scale — Chemistry: Indicators are Boyle's invention. He noticed that syrup of violets turned red with acids and green with alkalis, and rather than treating it as a curiosity he saw that it made ACIDITY into something testable rather than a matter of taste. He went on to soak paper in plant extracts, producing the first test papers, and to define acids and alkalis by what they DO — dissolve certain substances, react with each other, change these colours — rather than by any theory of what they are. That behavioural definition is essentially the one this page uses.
• Titrations — Chemistry: A titration is a procedure in which every detail carries a reason — the pipette rather than a measuring cylinder, the swirling, the drop-by-drop approach, the discarded rough run — and the conviction that such details must be published in full is Boyle's contribution to how experiments are reported. He described his apparatus and method at length, including the attempts that failed, on the grounds that a reader who cannot see the whole procedure cannot judge any of it. That standard is why a school practical can be written as a repeatable list at all.
• Preparing a Soluble Salt — Chemistry: Everything on this page exists to produce a PURE salt — the excess, the filtering, the slow crystallisation — and the idea that purity is a property requiring proof rather than an assumption is Boyle's. He argued that a substance should be judged by tests rather than by its reputation or its source, and that a chemist should say what was done to establish it. Crystallisation was one of his own criteria: a well-formed crystal was evidence of a single substance, since impurities disrupt the regular shape.
• Tests for Ions — Chemistry: This whole section rests on identifying substances by their reactions, and that approach is Boyle's programme. He argued against defining substances by origin or appearance and in favour of testing them, and he introduced several tests himself, including the use of plant extracts as indicators. His definition of an element — a substance that cannot be broken down further — is itself a test rather than a description, which is exactly the move this topic makes about ions.

Begin

• Start a conversation with Boyle — a dramatised, historically grounded AI portrayal
• Read the Historical Brief
• Explore the life of Boyle — five chapters
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