At the boarding school in Ljubljana, Marn was a favorite of the institution's head, Janez Zlatoust Pogačar, whom he assisted with translations and corrections for his Slovenski verski časopis (Slovene Religious Newspaper). His first publications appeared in 1849 in Ivan Navratil's children's magazine Vedež (Knowledge) as short articles with humorous and serious content: "Blagosrčni mladenič" (The Good-Natured Young Man), "Življenje-leto" (Life: A Year), "Povračilo" (Payment), "Kmet in tatje" (The Farmer and the Thieves), "Skopuha vmori glad pri zakladu" (Hunger Kills a Miser by His Treasure), "Vojak zares junak" (A Soldier, A True Hero), and "Plačilo nehvaležnosti in hudodelstva" (Payment for Ingratitude and Wickedness). In 1852, under the pseudonym Milko, he published the parable "Hrast in lipa" (The Oak and the Linden). As a primary school student, he edited the weekly manuscript publication Daničica (The Little Morning Star),Schwegel, Joseph. 2004. Na cesarjev ukaz: spomini politika in diplomata. Ljubljana: Slovenska matica, p. 43. and he contributed the story "7 pivcev o svojih ženah in njih 7 žen o svojih možeh" (Seven Drinkers Talk about Their Wives, and Their Seven Wives Talk about Their Husbands) to Jernej Lenček's almanac Slovenski romar (The Slovenian Pilgrim) in 1852.
