In our preoccupation with thc dramatic developments in the numerous fields of modern physics with their beautiful instrumentation and exciting revelations, we tend to forget our profound ignorance of some of the longest known pheno mena of physics. Among these were, until the middle nineteen hundred and thir ties, ferromagnetism, friction, lightning stroke, the common electric spark, and static electrification. The first two have now been pretty weIl clarified and the und erst an ding of both of these phenomena have contributed greatly to our under standing of the structure of matter and...