XLV. The law of molecular attraction

J.E. Mills
1912 The London Edinburgh and Dublin Philosophical Magazine and Journal of Science  
483 4. :Polonium and the active deposit of thorium emit a radiation which is completely absorbed /)y 0"64• 10 -4 cal. of alumlnlum. This radiation causes the emission of electrons from metals which it strikes. It consists of two portions, one of which is primary and not appreciably affected by an electric field; the other is secondary and consists of electrons whose velocities range from less than 3"8 • 10 ~ to more than 24"4• 10 ~cm'. Wertensteln has found that l~aC sec. emits similar soft
more » ... ts similar soft radiations, which ionize a gas; he attributes the primary radiation to the recoil atoms. 5. The secondary radiation is emitted not ooly by the source, but by any object on which a-rays are incident. The electrons of which it consists have considerably higher velocities than the S-rays hitherto recognized. 6. A part, at least, of the ordinary S-radiation is due, not to the direct action of the a-rays, but to these secondary rays. So far as can be concluded fr,m the present experiments, it is quite possible that the whole of the S-ray effect may be thus produced.
doi:10.1080/14786441008637353 fatcat:gawjydox5zdpnp3h5wkrfbgqom