ELECTROLYTIC DISSOCIATION
of his friends had heard of the visit, and, knowing what a *' leg-up " it would give the theory, had come to congratulate him in the usual Swedish way by drinking a glass of Swedish punch with him. Swedish punch is a very potent drink, but it would have taken more than that to muddle Arrhenius.
In dilute solutions the charged particles are so far from one another that the forces between them do not produce appreciable effects. In strong solutions, however, they will influence the arrangements of the ions throughout the solution; a study of this arrangement is of profound interest and importance, and has engaged, and is engaging, the attention of many eminent physicists.
Hertz and Electric Waves
In 1887 Heinrich Hertz, a young German physicist and a pupil of von Helmholtz, demonstrated for the first time the existence of waves of electric force. This discovery was of transcendental importance both for pure science and for its application to the service of man. It aroused great interest all over the world, and in no place more than in the Cavendish Laboratory, for the existence of electrical waves had been suggested and their theory developed by Clerk Maxwell, the first Cavendish Professor. Maxwell, soon after taking his degree, had been very much interested in Faraday's discoveries, and impressed by the extent to which he had been guided in making them by his conception of lines of electric and magnetic force. Faraday regarded an electric charge or a magnetic pole as the terminus of lines of electric force and magnetic force, stretching through space from charge to charge or from pole 391