First of all, Sherlock Holmes (1854-?), of course. Chemistry!
Michael Faraday (1791-1867) is next - representing Physics (and Chemistry, and being unreasonably beautiful):
Even later in life (plus, I love early photography!):
And, of course, Medicine: Joseph Lister (1827-1912). I like his Victorian seriousness in these pictures. And his hairstyle and of course his clothes! I don't know how many people will agree with me, but I find him very sexy :)!
And another one!
To be continued :)....