William Nicol and Henry Clifton Sorby

Abstract

MY article on Nicol and Sorby was intended to direct attention to two centenaries of especial interest in the history of microscopic petrography, that is, the examination of thin sections of rocks, which are, in most cases, mineral aggregates. It is generally recognized that the initial impetus to the development of this most important branch of geology was given by Sorby in the papers to which reference is made in my article; and also that the polarizing prism invented by Nicol and used by Sorby played an essential part in the development of the new science.