Description: Liquid cell.

Caption: The cell was placed between the electrodes of a high voltage source of several thousands of volts of static electricity. Kerr found that the plane of polarization of light passing through the cell was rotated. Kerr cells were used in early television cameras to modulate light. They have also been used as shutters in ultra high speed cameras.

Introduction: This is a modern demonstration cell made of a thin walled glass tube in the form of an upper case T with electrodes fused into the ends of the cross bar of the 'T'. The cell is filled with nitrobenzene. Kerr designed this type of cell to demonstrate the 'electro-optic effect' that is the interaction of two forms of energy, light and electricity.

Background: Early in 1875 Lord Kelvin entrusted his research programme, into the relationship between light, electricity and magnetism, to a lifelong friend, the Reverend John Kerr (1824-1907). Kerr had been a student at Glasgow in 1846 and one of the first members of Lord Kelvin's 'laboratory corps'. Kelvin allowed him to use his 'long-range electrometer' to measure the large electrical potentials which Kerr used in his experiments.

Historical Context: Donation to the Hunterian Museum - Who: Department of Natural Philosophy, now called Department of Physics and Astronomy, Glasgow University

Historical Context: Donation to the Hunterian Museum by the Department of Physics and Astronomy formerly the Department of Natural Philosophy, University of Glasgow - When: 1992 - Where: University Avenue, Glasgow, Scotland

Historical Context: Manufacture - When: 1960 - Where: University Avenue, Glasgow, Scotland - Who: Lloyd, John (Jack) Travers (fl.1948-1981)

Historical Context: Publication of the working principle of the liquid cell - When: 1875 - Where: London, England - Who: Kerr, John, The Reverend (1824-1907) Scottish cleric mathematician and physicist