In Vietnam war movies, you often see medics administering a white powder to wounds on soldiers. What is that powder? It usually comes from a pouch or a vial, and they sprinkle liberally on the wound.
At the time, sulphanilamide was seen as a wonder drug. It was originally used by the Allies in World War II. The 'sulpha' was used to fight infection.
Earlier forms of the sulpha drug also contained a cauterizing agent, which is why it was so urgently poured on open wounds. Of course there were painful side effects to the drug, but they were often preferable to an even more painful demise via infection.
Source
History of World War II Medicine
The Use of Sulphanilamide in Clinical Medicine