BETA RAYS

were first observed by Sir William Crookes, who found that when an electric current was pa ed through a vacuum tube, the negative pole gave off rays which faintly illuminated the molecules of the thin gas in the tube. They were later identified with one of the species of rays liberated by radium and were given the name Beta Rays by Sir Ernest Rutherford. Still later they were named Electrons, and were recognized as particles of electricity. The atoms of matter are now believed to consist of a positive nucleus, to which are attached electrons or negative particles of electricity. Radio-active substances spontaneously liberate from their atoms these particles, giving rise to the Beta Rays. They travel at an immense velocity, varying from 10,000 to more than 100,000 miles er second, according to conditions. hey are more than a you sand times smaller than the smallest known atom, and their ma is 7,4,- of that of an atom of hydrogen—the lightest gas known. The electric current is now believed to be caused by the rapid motion of electrons from atom to atom along the conductor, Beta Rays pa through opaque bodies, affect a photographic plate, promote chemical action and have many other remarkable properties which are still only partially investigated. NO:;), methyl hydroxide of dimethy glycocoll, occurring in sugar beet, vetch, cotton seed, and wheat.