ABSTRACT
Long-range particles which can be detected by their scintillations on a zinc sulphide screen are observed when α -particles pass through air or nitrogen, but not through oxygen or carbon dioxide. From the deflection of these particles in a magnetic field it appears that they were charged hydrogen atoms, indicating that some of the nitrogen atoms were disintegrated by an intense collision with an α particle. The gases oxygen, carbon dioxide, and sulphur dioxide were examined at absorptions of less than 32 cm of air. The particles liberated from all elements have a maximum range of at least 40 cm in air. We have no experimental evidence of the nature of these particles except in the case of nitrogen; it seems likely that the particles are in reality H atoms liberated at different speeds. The law connecting range and velocity of the particles is the same as for the α -particle, it follows the energy of the particle.
