In the winter of 1873-1874, Ramułt fell into a pond, causing a long-term illness and ailments which lasted for the rest of his life.
This led to his interest in the topic, initially via independent research into the language and culture of the Kashubians.
It documented the Kashubian language not as a mere dialect of Polish, as Aleksander Brückner and Hieronim Derdowski had seen it, but as a distinct Slavic language, identifying the Kashubians as the only remnant of a Pomeranian people who had settled on the southern Baltic coast, separate from other Slavs.
Toward the end of his life he moved from Lviv to Kraków, where his son Mirosław was a professor at the Jagiellonian University and where he worked in a room he called "Kashubia".
His tombstone in Kraków's Rakowicki Cemetery bears the inscription: "Stefan Ramułt, Kashubian-Pomeranian explorer.