The poem was translated by C. CHR. SONNE. This person is hard to track. The only thing I can find about him/her is that they translated a book that is currently unavailable on Amazon.UK. It's called Degeneration in Families: observations in a lunatic asylum. Awesome, right? No matter what name I am trying to research, I can almost always count on someone with the same name to show up on Facebook or LinkedIn.
The paper doesn't have a date on it, but it's fairly yellowed. The print is that purple-blue ink, and apparently, whiteout wasn't invented yet, or whomever wanted this translation didn't care about a few mistakes that were fixed with a pen.
There's a line that says "your visit to us a hundred years back was the cause of bleeding sores." I believe this is referencing the Battle of Copenhagen in 1807, but Holger died in 1908 and that would be putting him writing this poem a year before he died if it were exactly 100 years. I am stumped. It's a lovely poem, even if I'm not exactly certain about what it is referencing.