This picture was found in the possessions of a great-aunt who immigrated from Volhynia, Russia to Canada around 1908. My family is ethnically German, and many of the Volhynian Germans originally came from East Prussia. My vague guesses are that this is German/Prussian/Russian and is from approximately 1850-1908. I don't know who the man is. I can speculate that this is a military uniform.
Can anyone accurately identify his uniform (country, division, rank) or provide any other clues?