In lieu of an abstract, here is a brief excerpt of the content:1. IntroductionThe scientific efforts of Jesuits were the hot topics of the history of science. It was said that you could find a Jesuit behind most of the scientific accomplishments of the seventeenth or eighteenth centuries. The idea was not far from the truth because Athanasius Kircher of Rudjer Josip Bošković proved to be among the best. But Jesuit studies seem to have passed their peak and it is (...) time to research the early modern science successes of other religious orders. The Parisian Franciscan Marin Mersenne with his worldwide correspondence was the German-Roman Jesuit Kircher’s match and several other Franciscans were not less important. Therefore it is time to give the Franciscan scientists of the past centuries the fame they deserve.We celebrated the 800th anniversary of the Franciscan order in the year 2009. The Franciscans of Ljubljana were mentioned for the first time in 1242 as already established and resident in Ljubljana, soon after the establishment of Franciscan order. Later they were unable to survive the protestant challenge in 1569,1 when almost all citizens of Ljubljana accepted Luther’s Christianity. Although they never really left Ljubljana, the Franciscans officially returned to Ljubljana after several decades.Between the years 1646 and 1660 the Augustinian church of Annunciation of Our Lady was erected on behalf of the Baron Konrad Ruessenstein from the Upper Carniola castle Strmol. The front walls were finished in 1700, and half of a century later the famous Italian sculptor Francesco Robba made the main altar. The Emperor Josef II suppressed the Ljubljana Augustinians in 1784 and somewhat later gave their friary and church to their Franciscan neighbors from the opposite side of Ljubljanica River. The Barons Ruessensteins were not offended by the change and still took care for the church. The Baron Alexis Ruessenstein gave his important alchemical manuscripts to the new friary owners, the Franciscans.2After the death of the Emperor Josef II, Gabriel Gruber’s best student Jožef Marija Šemerl redesigned a former Franciscan Friary for a Lyceum. Gruber, who later became the General of the Jesuit Order, was among the best engineers in Habsburg Monarchy. The church of the Assumption of Our Lady was removed and leveled.3 After the earthquake Ljubljana got the market place in the former site of the Lyceum.The church of Annunciation of Our Lady or simply the Franciscan Church remains one of the most typical sightseeing posts in Ljubljana, even if the name of the square in front of it passed from Mary to France Prešeren, the greatest Slovenian poet, in the time of Communist regime in 1949.Click for larger viewFigure 1. The first page of the index of the copy of alchemistic manuscript of Alexis Baron Ruessenstein’s, the son of Konrad Baron Ruessenstein from the castle Strmol, Ruessenstein, ibid. FSLJ-29 F 54, 234–35 .Click for larger viewFigure 2. Alexis baron Ruessenstein about the Quicksilver in the copy of his original handwriting kept in Ljubljana Franciscan Library .Škerpin’s booksThe Ljubljana Franciscan Library was established in 1233.4 Žiga Škerpin renewed the Franciscan Library which was located on the right side of the Ljubljanica River during his lifetime. He was the provincial of Croatian-Carniolan province between the years 1732–1735 and again between the years 1745–1748. He became the court’s secret advisor,5 and acting general definitor of all Franciscans. During his numerous foreign travels, including Italy and Spain, he collected books. Between the years 1733–1746 Škerpin brought to Ljubljana no less than 1668 titles of.. (shrink)