Radio-activity of uranium

Abstract

1. The researches of M. Henri Becquerel have shown that compounds of uranium possess the property now called "radio-activity"; that is, rays emitted by them affect a sensitive photographic plate through bodies usually considered opaque to light; they discharge an electrometer when brought near it; and they are deflected by a magnet. These rays are now called "Becquerel rays," or "uranic rays."