In December of 1884, George B. Snow of Buffalo, New York, filed a patent application for his “inhaler” with its “capillary feeder leading from the [chloroform] reservoir below to the [nitrous oxide] inhaling-tube above”— from B to A in two of the filed diagrams (left). Snow’s filing was granted U.S. Patent No. 312771 in February of 1885, and he assigned patent rights to the Buffalo Dental Manufacturing Company. Within two months that company was advertising Snow’s innovation in the Dental Advertiser as a “Chloroform Mixer for Attachment to Nitrous Oxide Apparatus” (right). (Copyright © the American Society of Anesthesiologists, Inc.)