Black Dog (1869)
by
Carl Reichert
Carl Reichert (1835 - 1918) was an Austrian painter primarily known for his paintings of animals, particularly of dogs — and, to narrow it further, of dachsunds.
Reichert's painting Newfoundlander (also at The Cultured Newf) shows what is clearly a Newfoundland dog. Since the subject of Black Dog is not identified as a Newf but only as a "black dog," there's a good chance the dog here was not a Newf, although there are some points of resemblance to 19th Century Newfoundlands.