In 1733, "Medical Essays and Observations" was established by the Medical Society of Edinburgh as the first fully peer-reviewed journal. Peer review was introduced as an attempt to increase the quality and pertinence of submissions. Other important events in the history of academic journals include the establishment of "Nature" (1869) and "Science" (1880), the establishment of "Postmodern Culture" in 1990 as the first online-only journal, the foundation of arXiv in 1991 for the dissemination of preprints to be discussed prior to publication in a journal, and the establishment of "PLOS One" in 2006 as the first megajournal.