Abhorrence of a vacuum. A word devoid of meaning, imaginary principle used in ancient philosophy to explain why water rises in pumps and other similar phenomena. They said: water rises in pumps because nature abhors a vacuum. When it was noted that water only rose in pumps to the height of 32 feet, they went so far as to reach this point of absurdity, saying that nature only abhorred a vacuum to the height of 32 feet. But it was not long before someone discovered that mercury rose in pipes only to the height of 27 to 28 inches; and since it would have been too ridiculous to say that nature abhorred a vacuum for water up to 32 feet and for mercury only up to 28 inches, this strange explanation had to be abandoned; and soon thereafter, M. Pascal demonstrated in his treatise on the equilibrium of liquids , that all these effects were produced by the weight of air. This truth being universally accepted today, there is no need to extend this article any further here. See Air, Torricelli’s tube, and the treatise by M. Pascal cited here. [1]

Notes

1. Blaise Pascal, Traitez de l’equilibre des liqueurs, et de la pesanteur de la masse de l’air (1663). In English: The Physical Treatises of Pascal: The Equilibrium of Liquids and the Weight of the Mass of the Air (New York: Columbia University Press, 1937). There is no English translation available online, but see the exhibition from the University of Sydney Rare Book Library on the Origins of Modernity, which discusses it. There is also a French video from the University of Clermont-Ferrand that recreates Pascal’s experiment.