From the Wood Library-Museum’s Ben Z. Swanson Collection, this Albany Dental Association trade card used vivid images of a bird and flowers, even in this wintry scene (left). With nearly twice the number of franchises of the pioneering Colton Dental Association, Albany Dental administered no “Colton gas” (nitrous oxide) to patients; rather, they used a proprietary “secret preparation” (right), as mentioned on the reverse of this card from the Reading, Pennsylvania, franchise. By 1891, newspaper advertising in Reading had revealed the secret branding as “vitalized air”—just nitrous oxide supplemented with trace amounts of chloroform and alcohol. (Copyright © the American Society of Anesthesiologists’  Wood Library-Museum of Anesthesiology.)

From the Wood Library-Museum’s Ben Z. Swanson Collection, this Albany Dental Association trade card used vivid images of a bird and flowers, even in this wintry scene (left). With nearly twice the number of franchises of the pioneering Colton Dental Association, Albany Dental administered no “Colton gas” (nitrous oxide) to patients; rather, they used a proprietary “secret preparation” (right), as mentioned on the reverse of this card from the Reading, Pennsylvania, franchise. By 1891, newspaper advertising in Reading had revealed the secret branding as “vitalized air”—just nitrous oxide supplemented with trace amounts of chloroform and alcohol. (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.