It is long time since this communication (2005) so you may have got more information in the mean time. Hugo Magnus Hartvig was son of Ludvig and Paulina Hartvig living in Gothenburg, Sweden. He studied in England and met Emily there. It is unclear to me if he stayed or returned to Sweden. There is a note in a directory that H M Hartvig worked as a clerk in a firm in Gothenburg 1877.
Regards Gunnar Leman