Waller's Book Collection - Bibliotheca Walleriana
This collection takes its name from the collector Dr. Erik Waller (1875–1955) and it is considered to be, with its 20,000 titles, among the world's greatest and most valuable collections of medical history.
Erik Waller began in 1910 systematically to collect older medical and scientific literature. His ambition was to acquire all the books and works that had been influential in the history of medicine and related subjects. It is not easy to find lacunae or gaps in the Waller Collection. Among the 20,000 works there are 150 incunables, i.e. imprints from the 15th century, the first decades of the printing press. Many of them are extremely rare. 
Erik Waller's apartment in Stockholm - the library
Apart from medicine, Waller's library includes physics, chemistry, botany, zoology and astronomy.
The book collection was donated to Uppsala University Library in 1950. This internationally famous and impressive collection was amassed during a period of forty years.
The librarian, Hans Sallander, with his catalogue in two volumes created a worthy tribute to the collector. This catalogue can be found in the larger academic libraries and is now available online. Hans Sallander also wrote an accurate presentation of the Erik Waller's library in a journal article.
Collecting books however did not satisfy Erik Waller. To start with, he intended to collect autographs, i.e. hand written documents penned by famous people. His manuscript (or autograph) collection, comprising of around 38,000 items, is housed in Carolina Rediviva, as is his collection of off-prints, which is a good complement to his book collection and which extends from the 18th century to the mid 20th century.
In addition to all these documents Erik Waller also collected medals. Waller's medal collection, consisting of around 700 medals, is now held in the Uppsala University Coin Cabinet.
Catalogue
Bibliotheca Walleriana: the books illustrating the history of medicine and science collected by Dr Erik Waller and bequeathed to the Library of the Royal University of Uppsala: a catalogue / compiled by Hans Sallander. - 2 vols. - Stockholm : Almqvist & Wiksell, 1955. - (Acta Bibliothecae R. Universitatis Upsaliensis; 8-9)
Further reading
Sallander, Hans, The Bibliotheca Walleriana in the Uppsala University Library (In: Nordisk tidskrift för bok- och biblioteksväsen, Vol. 38, 1951, p. 49-74)