FIGURE 3.
Ray Lyman Wilbur, MD. March 5, 1929. From the Library of Congress https://www.loc.gov/pictures/resource/npcc.17100/.
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.