the majority of the population are not affected by black-white color blindness. Mathematics and logic Ladd-Franklin was the first woman to have a published paper in the Analyst. She was also the first woman to receive a PhD in mathematics and logic. The majority of her publications were based on visual processes and logic. Her views on logic influenced Charles S. Peirce's logic and she was highly praised by Arthur Prior. Professional involvement Ladd-Franklin was among the first women to be inducted into the American Psychological Association in December 1893. From 1894 to 1925, Ladd-Franklin presented ten papers at APA meetings. She was also one of the first female members of the Optical Society of America in 1919. During their meetings she presented six papers and two exhibits. Ladd-Franklin was included in the Who's Who in America during 1901-1902 and 1914-1915. Ladd-Franklin remained a member of both scientific societies until her death. She was also a prominent member of the women's rights movement. In 1948, Bertrand Russell wrote: "I once received a letter from an eminent logician, Mrs. Christine Ladd-Franklin, saying that she was a solipsist, and was surprised that there were no others. Coming from a logician and a solipsist, her surprise surprised me." Published works "Quaternions", The Analyst v. 4, n. 6, pp. 172–4 (Nov 1877). Google Books The Analyst p. 172 in n. 6 (November) in v. 4 (1877). Also JSTOR "Quaternions" first page. (Several journals have been called "The Analyst". See The Analyst (disambiguation). Internet searches for The Analyst, the one which became The Annals of Mathematics, should use the search phrase "The Analyst" mathematics, otherwise The Analyst about chemistry will dominate search results.) "On the Algebra of Logic" in Studies in Logic, C. S. Peirce, ed., pp. 17–71, 1883. Google Books Eprint. Internet Archive Eprint. "A Method for the Experimental Determination of the Horopter" in the American Journal of Psychology, v. 1, n. 1 pp. 99–111, November 1887. JSTOR . "On Some Characteristics of Symbolic Logic" in the American Journal of Psychology, v. 2, n. 4, pp. 543–567, August 1889. Google Books Eprint. Internet Archive Eprint. "Epistemology for the logician" in Verhandlungen des III. Internationalen Kongresses fur Philosophie., pp. 64–670, 1908. Also separately as an offprint. "Charles Peirce at the Johns Hopkins", The Journal of Philosophy, Psychology, and Scientific Methods v. 13, n. 26, 715–723, December 1916. Google Books Eprint (badly done) and seek the