40th anniversary of the 1898 discovery of radium by Pierre and Marie Curie

This semi-postal stamp commemorates the 40th anniversary of the 1898 discovery of radium by Pierre and Marie Curie, issued as a fundraising initiative for the International Union Against Cancer (Union Internationale Contre le Cancer). The fine line engraving shows the pioneering scientists huddled over laboratory apparatus, capturing a profound message of academic dedication, scientific progress, and humanitarian hope through the medical applications of radiotherapy. In the context of 1930s Mauritania—then a sparsely populated French colony managed from Saint-Louis in neighboring Senegal—modern healthcare facilities and oncological treatments were virtually non-existent locally. By distributing this worldwide French Republic (R.F.) campaign stamp in the territory, the postal program underscored an effort to support global medical research, symbolically connecting the remote West African colony to the vanguard of international scientific and humanitarian endeavors.