Portugal - Belem, Monument of the Discoveries, Dear Doctor

Monument of the Discoveries in Belem, outside Lisbon, commemorates the 500th anniversary of Prince Henry the Navigator pioneer of maritime discovery.

This is a medical advertising postmarked mailed in 1961 to a doctor in West Virginia, USA.

On the back of the card these words are printed:

Dear Doctor:
Here in Portugal, our special stamp commemorates the life, 5 centuries ago, of Prince Henry the Navigator.  Today PENTOTHAL too has charted new worlds of progress.  You'll like its dependable, easily controlled intravenous anesthesia.  Use it soon.
Abbott

(Here is the stamp on the postcard.)