The evolution of life / by H. Charlton Bastian.

  • Bastian, H. Charlton.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The evolution of life / by H. Charlton Bastian. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    30/420 (page 6)
    Later, the researches of Professor J. J. Thomson ^ and his school have shown that in the conduction of electricity through highly rarefied gases the particles shot out from the cathode (or negative pole), con- stituting the above-mentioned cathode rays, always carry an electrical charge identical with that conveyed by a single atom of hydrogen, though each particle in these cathode rays associated with this constant minimum charge has only about i^Vn of the bulk of the hydrogen atom ; and, more important still, that the particle is always of the same kind and size whatever the substance may be from which the cathode ray emanates. Such particles, all identical in mass and in the charge which they carry, are by Professor Thomson named corpuscles, though they are more commonly spoken of as electrons— a name previously suggested by Dr Johnstone Stoney, and indicative of the view now held by many that these elementary corpuscles are in reality electrical units. These corpuscles or electrons are indeed now supposed to be the elementary units out of which the atoms of the various chemical elements are compounded—their number in each atom being very great, and increasing with each increase in the atomic weights of the several elements. Thus, while an atom of hydrogen whose atomic weight is very low (i) has been supposed to contain looo of these corpuscles or negative electrons,^ an atom of mercury, with a very high atomic weight (200), has been supposed to contain 100,000 of such 1 Conduction of Electricity through Gases, 1903.