This edition is flawed in that it does not include the scalar field of previous editions. In the 7th Ed. an experiment is described which supports the existence of the scalar field. In the 8th Ed. it is shown that classical electromagnetism predicts the existence of the scalar field. Furthermore, without the scalar field, all the conservation laws break in electromagnetism.
The only interesting thing about the 6th Ed. is that it demonstrates that, even without the scalar field, electromagnetic theory (done correctly) still undercuts relativity.