In the preface to this work, Professor Rothberger expresses the belief that Dr. Dressler has met the requirements for introducing clinical electrocardiography to the practitioner of medicine. This belief is amply justified by the work. It is accurate, succinct, clear and a model of simplicity. It deals mainly with proved facts and touches only lightly that speculative field that brings confusion to all except the advanced student.
The first three chapters deal with the principles of the galvanometer, with the instrument itself and with the normal electrocardiogram. Following this is a discussion of the alterations produced by malposition and by hypertrophy of the heart. Against this portion of the book a just criticism may be advanced. The author states, without qualification, that right or left ventricular hypertrophy may be determined from the electrocardiogram. Many observers believe that muscle mass and electrical activity are frequently but not always associated. It is