19th century as requested:
Charles Babbage, Passages from the life of a philosopher, 1864.
George Biddell Airy, Autobiography of Sir George Biddell Airy, 1896.
French scientists often wrote (and still write), not full-fledged autobiographies but comprehensive “Notices sur les travaux scientifiques” as candidates to the Academy of Sciences: Darboux (1884), Poincaré (1886, updated in 1901), Picard (1889), Appell (1892), Goursat (1900), Painlevé (1900), Fatou (1929).
20th century, another:
- Hans Freudenthal, Schrijf dat op, Hans. Knipsels uit een leven (Write that down, Hans. Excerpts from a life). Amsterdam: Meulenhoff, 1987.