Joseph Plateau

Joseph Plateau (1801 - 1883) - was a Belgian physicist, most notable for noticing the illusion of a moving image and his experiment about surface tension.

Although there is no correspondence between Joseph Plateau and D'Arcy Thompson, his experiments on soap-films and oil globules substantially influenced some key ideas on the 'Forms of Cells' chapter in D'Arcy's book. Thompson corresponded about this experiment and even attempted to replicate it in 1920 (ms22338).

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Joseph Plateau

The Experiment


Published in 1873 Plateau's experiment involves a globule of oil lying in a fluid, made out of water and alcohol. The oil takes on a spherical shape at the start. Then, if one starts to spin the globule around its own axis, it starts to flatten out at the poles of the axis. If velocity is increased the oil takes up a shape of torus, which is separated from the axis. If the speed is increased even more, the torus breaks up into small spheres which rotate around their own axis. For more information: click THIS LINK.

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Apparatus for Plateau's experiment
Photo M.D. Collection J.Plateau, Ghent


The soap-bubble experiment involved a soap bubble between two pipes. When the pipes are drawn further apart the spherical bubble transforms into a cylinder. If they are drawn even further apart the cylinder narrows down in the middle and becomes an unduloid. (Figure: Soap film)

Thompson relates both of these experiments to the shapes of cells and single-cell organisms, since he claims that they are primarily affected by surface tension (and not gravity or other forces). Hence, the experiments are used to explain the shapes of cells and single-cell organisms. He also relies on more of Pleateau's work later on in the book (see Chapter 3 of the On Growth and Form).

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Soap film - cylinder becoming an unduloid
Photo From Wikimedia Commons, the free media repository

Felix Plateau


Felix Plateau, son of Joseph Plateau, was a Belgian biologist. D'Arcy corresponded with Felix Plateau between 1886 to 1908. All letters were written in French (ms22329-ms22337). They mainly corresponded about natural history, discussed specimens, studies and developments as well as personal and career news.

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Felix Plateau


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Charles Robert Darling

D'Arcy's test script for Tait's class