Which French institution received Becquerel's first 1896 reports on uranium rays?

The French Academy of Sciences received Henri Becquerel’s first 1896 reports on uranium rays. He presented short communications to the Academy in Paris as he investigated radiation emitted by uranium compounds.

Becquerel’s work followed Wilhelm Röntgen’s 1895 discovery of X-rays. At an Academy meeting in January 1896, discussion of Röntgen’s results prompted Becquerel to test whether fluorescent substances might produce similar penetrating rays. His uranium salts unexpectedly fogged photographic plates, even when shielded from sunlight.

He reported the early results rapidly through the Academy’s Comptes rendus, a journal designed for quick publication of scientific communications. In February and March 1896, his successive notes established that uranium radiation was spontaneous and did not depend on prior exposure to light.

The institution is sometimes confused with the University of Paris because Becquerel held academic posts in Paris, or with the Pasteur Institute, which was founded in 1887. Neither received these first reports. The Academy later became central to the history of radioactivity, including the Curies’ announcements of polonium and radium.