---
title: "Robert Boyle"
chunk: 2/4
source: "https://en.wikipedia.org/wiki/Robert_Boyle"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:05:54.217837+00:00"
instance: "kb-cron"
---

In 1668 he left Oxford for London where he resided at the house of his elder sister Katherine Jones, Lady Ranelagh, in Pall Mall. He experimented in the laboratory she had in her home and attended her salon of intellectuals interested in the sciences. The siblings maintained "a lifelong intellectual partnership, where brother and sister shared medical remedies, promoted each other's scientific ideas, and edited each other's manuscripts." His contemporaries widely acknowledged Katherine's influence on his work, but later historiographers dropped discussion of her accomplishments and relationship to her brother from their histories.

=== Later years ===

In 1669 his health, never very strong, began to fail seriously and he gradually withdrew from his public engagements, ceasing his communications to the Royal Society, and advertising his desire to be excused from receiving guests, "unless upon occasions very extraordinary", on Tuesday and Friday forenoon, and Wednesday and Saturday afternoon. In the leisure thus gained he wished to "recruit his spirits, range his papers", and prepare some important chemical investigations which he proposed to leave "as a kind of Hermetic legacy to the studious disciples of that art", but of which he did not make known the nature. His health became still worse in 1691, and he died on 31 December that year, just a week after the death of his sister, Katherine, in whose home he had lived and with whom he had shared scientific pursuits for more than twenty years. Boyle died from paralysis. He was buried in the churchyard of St Martin-in-the-Fields, his funeral sermon being preached by his friend, Bishop Gilbert Burnet. In his will, Boyle endowed a series of lectures that came to be known as the Boyle Lectures.

== Scientific contributions ==
 Boyle's great merit as a scientific investigator is that he carried out the principles which Francis Bacon espoused in the Novum Organum. Yet he would not avow himself a follower of Bacon, or indeed of any other teacher.

=== Emphasis on experiments ===
On several occasions, he mentions that to keep his judgment as unprepossessed as might be with any of the modern theories of philosophy, until he was "provided of experiments" to help him judge of them. He refrained from any study of the atomical and the Cartesian systems, and even of the Novum Organum itself, though he admits to "transiently consulting" them about a few particulars. Nothing was more alien to his mental temperament than the spinning of hypotheses. "I, ... love not to believe any thing upon Conjectures, when by a not over-difficult Experiment I can try whether it be True or no..."
He regarded the acquisition of knowledge as an end in itself, and in consequence, he gained a wider outlook on the aims of scientific inquiry than had been enjoyed by his predecessors for many centuries. This, however, did not mean that he paid no attention to the practical application of science, nor that he despised practical knowledge.

=== Physics and Chemistry ===

==== Vacuum pump ====
To Boyle, Guericke's vacuum pump had two important limitations. Firstly, its evacuation required "the continual labour of two strong men for divers hours", and secondly, "the Receiver, or Glass to be empty'd, consisting of one entire and uninterrupted Globe ... of Glass ... is so made, that things cannot be convey'd into it". Hooke constructed a pump that could be operated on a desktop, and conveniently opened to insert candles, mice, birds, bells, pendulums, and other research objects. With Hooke's pump, Boyle began a series of experiments on the properties of air. An account of Boyle's work with the pump was published in 1660 under the title New Experiments Physico-Mechanical, Touching the Spring of the Air, and its Effects.

==== Chemistry ====
Robert Boyle was an alchemist; and believing the transmutation of metals to be a possibility, he carried out experiments in the hope of achieving it; and he was instrumental in obtaining the repeal, by the Royal Mines Act 1688 (1 Will. & Mar. c. 30), of the statute of Henry IV against multiplying gold and silver, the Gold and Silver Act 1403 (5 Hen. 4. c. 4). With all the important work he accomplished in physics, chemistry was his peculiar and favourite study. His first book on the subject was The Sceptical Chymist, published in 1661, in which he criticised the "experiments whereby vulgar Spagyrists are wont to endeavour to evince their Salt, Sulphur and Mercury to be the true Principles of Things". For him, chemistry was the science of the composition of substances, not merely an adjunct to the arts of the alchemist or the physician.

==== Elements, compounds, and particles of matter ====
Boyle endorsed the view of elements as the undecomposable constituents of material bodies; and made the distinction between mixtures and compounds. He made considerable progress in the technique of detecting their ingredients, a process which he designated by the term "analysis". He further supposed that the elements were ultimately composed of particles of various sorts and sizes, into which, however, they were not to be resolved in any known way. He studied the chemistry of combustion and of respiration, and conducted experiments in physiology, where, however, he was hampered by the "tenderness of his nature" which kept him from anatomical dissections, especially vivisections, though he knew them to be "most instructing".

==== "Factitious airs" ====
Around 1670, upon producing what is now known to be hydrogen, Boyle coined the term "factitious airs". Factitious means "artificial, not natural". Later, English chemist and physicist Henry Cavendish used the term "factitious air" to refer to "any kind of air which is contained in other bodies in an unelastic state, and is produced from thence by art".

==== Heat ====
Like English philosopher Francis Bacon, Galileo Galilei, and Robert Hooke had done before him, Boyle declared that heat consists of the motion of the invisible, constituent particles of objects.