ABSTRACT
In his classic cathode ray paper of October 1897, as in his Royal Institution Discourse earlier that year, Thomson had declared that 'the smallness of cathode may be due to the smallness of m or the largeness of e'o He put it more strongly in the October paper with the added statement that 'the smallness of the value of mje is 0 0. due to the largeness of e as well as the smallness of m [italics added]'-something he justified vaguely in terms of the high specific inductive capacity of gaseous molecules as an 'additive quantity' Before long he abandoned this however. As he relates in his Recollections,
After long consideration of the experiments it seemed to me that there was no escape from the following conclusions: (1) That atoms are not indivisible, for negatively electrified particles can be torn from them by the action of electrical forces, impact of moving atoms, ultraviolet light or heat. (2) That these particles are all of the same mass, and carry the same charge of negative from whatever kind of atom they may be derived, and are a constituent of all atoms. (3) That the mass of these particles is less than one-thousandth part of the mass of an atom of hydrogen. [10-2]
That the high for the charge is solely due to smallness of m follows from first conclusion, that atoms are not indivisible. If an electrically neutral atom contains one or more particles, each of mass m and negative charge e, then tearing a particle from the atom leaves an ion with an unbalanced positive charge of magnitude e. If n particles are torn off, the residual ion will be left with an unbalanced positive charge ne. Thus, the unbalanced positive ionic charge may be greater than or to the charge of each of its constituent
particles, but the latter charge carmot exceed the residual ionic charge [10-3].
