The University of Toronto Libraries is the largest academic library system in Canada and ranks third among peer institutions in North America — with more than 15 million volumes in 341 languages, millions of electronic materials, as well as over 31,000 linear meters of archival material. The Thomas Fisher Rare Book Library has large and comprehensive collections in several key areas of the history of theoretical and applied science, with one of its principal focuses being the science of the Renaissance prior to Galileo. The Fisher also has large holdings in the history of medicine, particularly anatomy, obstetrics and dentistry. The discovery of insulin at the University of Toronto is also well documented within the Fisher's archival collections.