Charles E. Sprague, Hand-book of Volapük — 22 (1887)
“ Into expresses motion from the outside to the interior, while in relates wholly to the interior.This distinction is exprest in Volapük either by putting the noun into the kimifal or by adding -i to the preposition. In Volapük there are other prepositions subject to the same distinction; when they denote place, where, they govern the kimfal; when they denote direction, whither, they govern the kimifal or take the ending i. ”
