Artist and date unknown
Robert Boyle was born on January 25, 1627, in Lismore Castle in Ireland, his father being the first Earl of Cork, his mother Catharine Fenton, the daughter of a secretary of state in Ireland. He was educated at home and when he was eight years old and after the death of his mother, he went to Eton College and then spent extended stays in France, Italy, and Switzerland. He had an aristocratic demeanor and was also deeply religious. At the same time, he was much interested in science. In 1644, Boyle moved to England to the estate at Stalbridge in Dover bequeathed to him by his father. In Stalbridge, he installed a laboratory and began many kinds of scientific investigations, an activity that preoccupied him during most of the rest of his life. Initially, his experiments involved chemistry, about which he wrote a book in 1661, titled The Skeptical Chymist, that established him as a leading force in chemistry at his time. In 1655, he moved to Oxford where he joined a group of natural philosophers. He continued experimental work and hired Robert Hooke (1635–1703) as an assistant. With Hooke’s assistance, Boyle developed an improved version of Otto von Guericke’s vacuum pump about which he had read in 1657. In England, he is considered the originator of “Boyle’s law,” the fact that in a closed system and at a constant temperature, the volume and mass of a gas are inversely proportional, elsewhere known as Mariotte’s law. While living in Oxford, he published many extended texts on various scientific and philosophical subjects.
20.1 Experiments and Considerations Touching Colours
In 1664, Boyle published a book on “Experiments and Considerations Touching Colours” with over 400 pages, indicating that the subject of color had deeply interested him and led to many experiments [1]. The book was published in two English and six Latin editions, most of the latter in European countries. In 1660, the Royal Society was founded with Boyle as one of its founding members. They published most of his scientific works at the time. Boyle wrote very extensively during his life. The manuscript pages on science alone number over 8000 [2]. In 1668, he moved to London into the residence of his sister Katherine (Lady Ranelagh) who also had an interest in science. He died on Dec. 31, 1691, one week after his sister’s death.
Boyle’s book on color was written at a time when there was still little objective information about the subject. It is primarily a statement of the state of the art of knowledge at the time. He was puzzled about how to put the multitude of facts on color into a coherent system. The book consists of three parts: The first one is a presentation of the then current knowledge and its problems and missing parts. In the second one, he describes his experiments and interpretation of the nature of whiteness and blackness. In the third part, he describes a further 50 experiments on various aspects of colors and their results. As a chemist, he is particularly confused about the multitude of different colors occurring in various kinds of chemical reactions without any apparent system behind them.
Illustration from [1] of Boyle’s experiment with a glass prism. It is struck by two beams of light from the right side. Parts of the light are reflected (C and γ) and parts refracted (E and ε) where five colors are displayed, 1 being red, 2 yellow, 3 green, 4 blue, and 5 purple. He also found the spectra displayed in two other locations, l and I [1]
almost numberless differing colours … [painters] need employ any more than White, and Black, and Red, and Blue, and Yellow; these five, variously compounded …. being sufficient to exhibit a variety and number of colours such, as those that are altogether strangers to the painters’ palettes, can hardly imagine.
He also projected the spectral colors obtained with a prism onto various colored materials and observed the results of mixing “real” and “emphatical” colors. He also projected two spectra obtained from prisms in different ways on top of each other, as he pleased. He only reported having obtained a green from overlapping yellow and blue light and a purple from blue and red.
Boyle’s prism experiments, together with those of other authors, proved to be inspirational for young Isaac Newton, a student at Cambridge when Boyle’s book got published. When he submitted his early papers on color to the Royal Society, Boyle was one of the reviewers before publication.