I ended up studying this poem last year:
This is a congratulatory poem in a dissertation at the Academy of Turku from 1759. It is on page 4 of the full dissertation. I also published an English translation of the poem in hexameter, together with an analysis (with J. Stén).
My question concerns orthographic details. There are two versions of the letter S, a normal one ("short S") used in word-final positions and a "long S" used in other positions. I do not know if the names "short" and "long" are standard, but I hope the intention is clear enough. (It turns out "long S" is the standard name, and the normal short one is "round" or "terminal"; see comments.) This rule seems pretty obvious, and it parallels the Greek use of two sigmas.
However, there are two points that I want clarification for:
- On the first line: Cum modo diSjectis…
- On line 19: LEXELL aSSiduos inter…
Why is the S in disjectis short? I assume it is because it is the final letter of the prefix dis-, and therefore considered word-final. Reading through pages 2 and 3 reveals that SJ in Swedish is always spelled with long S. Perhaps the ligature SJ is avoided in Latin to emphasize that it is pronounced so differently in Swedish. This would also fit the observation that the ligature SI with long S is not avoided in the poem.
Assuming that prefixes should end in a short S, the first S in assiduos should be short. Why is it long? Is it because of "attraction" by the adjacent S which starts siduos is therefore long? Or is as- not realized to be a prefix?
Side question: Is this consistent with typographical conventions of the era? Are these two points exceptional, or is this something to be expected in general?
I realize that the question may be more about typographical conventions than Latin in itself, but I hope this is still a good place to ask.