The first fifteen volumes of these "Notes of Travel" are Lea's account of his trips to Europe during 1832 and 1852-1853. He met with naturalists, scientists, and did much sightseeing in England, France, Germany, Italy, and Austria. He records in detail visits and discussions with scientists, and makes sketches of many of the places he saw, particularly the Rhine River. The sixteenth volume is a memorandum book, 1853, containing accounts and expenses while in Europe.

Ernst Krackowizer (1821-1875), father-in-law to the anthropologist Franz Boas (APS 1903), was an Austrian born surgeon who fled Vienna to New York following his involvement as captain of the Academic Legion during the Revolution of 1848. Krackowizer was an active member of New York medical community, helping to found the German Dispensary and Hospital, later renamed Lenox Hill Hospital. During the Civil War, Krackowizer assisted the Union Army as a volunteer surgeon and inspector of military hospitals. Krackowizer is claimed to have been the first on whom the anesthetic effects of chloroform were tested in Vienna and the first to use a laryngoscope in the United States. This collection is comprised of the personal papers of Ernst Krackowizer including diplomas, certificates, correspondence, diaries, and photographs, which document his life and medical career. Krackowizer's experience in the Revolution of 1848 and subsequent flight from Vienna trough Germany to the United States is well detailed in his correspondence to his fiancée and later wife, Emilie Forster, and in his diaries, which make up a significant portion of this collection. Krackowizer firsthand description of the early use of chloroform and the laryngoscope are included, as well as materials documenting his involvement as a volunteer surgeon and hospital inspector during the Civil War. Additionally, the Krackowizer Papers contain material written by others reference the life and work of Ernst Krackowizer.