Frederick Dixon was a teacher and the editor (from 1914) of the Christian Science Monitor.
Whistler appears to have met Dixon in 1888.
:Deat of Mr Frederick Dizon', The Times, London, Monday, 26 November 1923, p. 14; Mary Baker Eddy Institute at www.mbeinstitute.org (accessed 2005); The Nation, Volume113, No. 2937, 19 October 1921 at www.nationarchive.com (accessed 2005).