JOHN KERR, the discoverer of the Kerr effect in magneto-optics, was born at Ardrossan, Ayrshire, December 17, 1824, and receive part of his early education at a paeish school in Syke. He graduated M.A. with honours in 1849 at Glasgow University, where he greatly distinguished himself, especially in mathematics and natural philosophy. He completed the usual course in theology at the Free Church Collage in Glasgow, but, instead of entering on a clerical career, became in 1857 mathematical lecturer in the Free Church Normal Training College for Teachers in Glasgow, an institution which has recently passed under the direct control of the Scottish Education Department. Here for forty-four years he trained in mathematics and physics thousands of our youth who afterwards filled important scholastic positions. On his retirement in 1901 his old pupils entertained him at a banquet, when Prof. Magnus Maclean in their name presented him with a tea and coffee service, and made a graceful reference to his great work.