Heidbrink v. McKesson

DENISON, Circuit Judge.

These patents relate to devices for administering anaesthetics. Nitrous oxide was commonly used where effectiveness for very short periods was sufficient, as in tooth extraction; but if its administration was long continued it became dangerous. Accordingly a process was developed by which oxygen could be mixed with the nitrous oxide, and a more prolonged use of the anaesthetic became feasible. In practice, the operator procured his gases from prepared tanks, which contained the respective gases at high pressure, and in that form were a market product. It was found that…