At the northwest corner of 10th & Green Streets in Philadelphia, Pennsylvania, Dr. Herbert Arlington Stoughton practiced as “a dental expert.” The reverse (back, right) of his trade card notes that his laughing gas was made “fresh daily,” an important point in the late 1800s when leaky anesthetic equipment and even pockets of moisture could rob gas mixtures of their potency. Before the widespread use of compressed gas cylinders for nitrous oxide, many dentists and surgeons had to “bake up” their own laughing gas for anesthetic purposes. Advertised at “only 50 c.” (cents), the nitrous oxide gas cost about $67 in labor value in year 2015 U.S. dollars. On the obverse (front, left) of Dr. Stoughton’s trade card, he used an eye-catching image of a young woman with long tresses covered partially by a red bonnet. Note, however, that he chose not to stamp any additional business information onto the white blank space provided at the obverse’s bottom by the manufacturer of this mass-produced trade card. This item is part of the Wood Library-Museum’s Ben Z. Swanson Collection. (Copyright © the American Society of Anesthesiologists, Inc.)