Official websites use .gov A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
View of three U.S. Public Health Service officers loading canisters onto the back of a truck while a fourth man, standing by the passenger side, looks on.
Copyright:
The National Library of Medicine believes this item to be in the public domain. (More information)