In comparison with other major libraries the Academy of Sciences Library holds a smaller number of rare volumes. Consigned to a special depository are manuscripts, incunabula and documents of an archival nature, around a hundred of each, which are linked to approximately 25,000 volumes of books from the 16th–18th centuries, in some cases extending to the mid-19th century. Although the ASL historical collection is not fully bound up with the history of the ASL itself, its composition makes it an important part of the national literary heritage. Despite the historical “youth” of the organization, in operation since 1st January 1953, the ASL also houses books whose origin reaches far back into the past before the founding of the library. Some of them originate from the book collections of scientific institutes which were disbanded during the creation of the Czechslovak Academy of Sciences in 1952 and whose libraries became the literary foundation of the newly established Main Library of the Czechoslovak Academy of Sciences (hereinafter only “Main Library CSAS”). These were the library of the Royal Czech Society of Sciences (1784–1952), the library of the Czech Academy of Science and the Arts (1890–1952) and the library of the Masaryk Academy of Work (1920–1952). To this day these book collections reflect the history of their formation and development, means of bibliographic processing and scholarly use. At the same time they have preserved for us an extensive basis of sources on the history of science, since they brought together scientific literature from the domestic and foreign publishing production of their time. However, from the outset these libraries crossed the time boundary of the founding of their institutions, for example, through bequests of the private libraries of some scientists, by means of which books from past centuries were also incorporated into their collections. For example, many of the oldest printed works entered the library of the Royal Czech Society of Sciences from the estate of its first secretary Tobiáš Gruber, being acquired in 1806, and from the collection of František Kadeřávek († 1961), professor of descriptive geometry and stereotomy at the Czech Technical University in Prague, who had purchased a number of early printed books from the Thun-Hohenstein family’s library in Děčín, sold at auction in 1933.
Between 1953 and 1967 the Main Library CSAS continued to increase the number of the oldest books through antiquarian purchases and the acquisition of various estates or closure of historical libraries. the content of the current ASL historical collection is therefore extremely varied, especially with regard to manuscripts and archive material. It encompasses an unexpected range of genres and subjects, from a 13th-century New Testament written in Greek to Břetislav Schuster’s manuscript collection of painted heraldic emblems from 1960–1966. When a printed inventory was compiled in the 1980s, 786 examples of interesting works produced by printworks in the 16th century were recorded among the earlier printed books. 17th-century publications at the ASL number approximately half as many again. In spite of the diversity of the content and the fact that this is not a “historically shaped” collection, it can be said that the early printed works housed at the ASL represent an illustrative cross section of the printing and literary output of the 16th–18th centuries.