The first achromatic microscope, 1826.

Made by James Smith for Joseph Jackson Lister (1786- 1869), father of Joseph Lister, the surgeon and pioneer of antisepsis . Lister was an eminent English microscopist. This is posibly the most important optical microscope ever made and uses an achromatic objective lens corrected for chromatic and spherical aberrations. This eliminates the problem of chromatic aberration, where coloured fringes appear around objects. The image was at the time the clearest produced by any microscope.