Unpublished letter, regarding imperfect vision from Whitlock Nicholl to Sir Joseph Banks In this covering letter for Nicholl's paper found at AP/9/19/1, he introduces his paper and acknowledges that he chose to submit it because Banks had previously responded favourably to another paper on colour blindness submitted by Nicholl but not published. He writes in a post-script note that he had previously sent another earlier draft of the paper (found at AP/9/19/2) along with correspondence (AP/9/19/4-6), but supposed that this had not been received. Subject: Physiology Written by Nicholl in Ludlow [Shropshire, England]. 16 June 1820