Besides ether, which has long been associated with Harvard, the proprietary Harvard Dental Parlors offered other anesthetics, including Mayo’s Vegetable Vapor. As originally patented, “Mayo’s Vapor” supplemented nitrous oxide with alcohol, hops, and opium to prolong the anesthetic duration of the laughing gas. Only the Boston directories for 1889 and 1890 list “Dr. L. M. Morse” (right) at the 68 Boylston Street address (lower left) on the reverse of his trade card. Refining the date further, a newspaper advertisement from April of 1890 matches exactly Morse’s anesthetic offerings (upper left) from the trade card’s reverse: “Liquid Nitrous Oxide Gas, Vitalized Air, New Anaesthetic, Mayo’s Vegetable Vapor, Sleeping Vapor or Ether.” (Copyright © the American Society of Anesthesiologists’ Wood Library-Museum of Anesthesiology.)

Besides ether, which has long been associated with Harvard, the proprietary Harvard Dental Parlors offered other anesthetics, including Mayo’s Vegetable Vapor. As originally patented, “Mayo’s Vapor” supplemented nitrous oxide with alcohol, hops, and opium to prolong the anesthetic duration of the laughing gas. Only the Boston directories for 1889 and 1890 list “Dr. L. M. Morse” (right) at the 68 Boylston Street address (lower left) on the reverse of his trade card. Refining the date further, a newspaper advertisement from April of 1890 matches exactly Morse’s anesthetic offerings (upper left) from the trade card’s reverse: “Liquid Nitrous Oxide Gas, Vitalized Air, New Anaesthetic, Mayo’s Vegetable Vapor, Sleeping Vapor or Ether.” (Copyright © the American Society of Anesthesiologists’ Wood Library-Museum of Anesthesiology.)

George S. Bause, M.D., M.P.H., Honorary Curator and Laureate of the History of Anesthesia, Wood Library-Museum of Anesthesiology, Schaumburg, Illinois, and Clinical Associate Professor, Case Western Reserve University, Cleveland, Ohio. UJYC@aol.com.