THERE is a real need for text-books covering a self-cofitaihed lecture course on atomic physics. By depleting drastically from the historical order of development, a very wide ground may be covered even with students at a comparatively early stage. It is possible to make such a course relatively simple to follow and yet to include most of the important features of modern atomic, including nuclear, physics. The developments associated with atomic energy have raised the educational requirements for this branch of physics, so the demand for appropriate text-books should be considerable. Introduction to Atomic Physics By Dr. Henry Semat. Revised and enlarged edition. Pp. xi + 412. (New York: Rinehart and Co., Inc., 1946.) 4.50 dollars.