Hypnotism for Medical and Dental Practitioners

of heart sounds through a loud-speaker is less satisfactory than simultaneous listening by each member of the class through individual stethophones. They also have found that simultaneous audio-visual demonstration of the sounds is a technique of very great value, since the reception together of sound by the ear and its graphic pattern by the eye watching an oscilloscope or direct-writing stethograph is much more impressive than their reception separately. The book provides the reader with quite a good mental refresher on the auscultatory phenomena of all kinds of heart disease, and it is illustrated with fifty or sixty stethograrns, many of them with superimposed electrocardiograms or sphygrnograms. There is satisfactory discussion of the origin of heart sounds and of the factors which modify their perception, including the type of stethoscope and the limitations of the human ear. The book is lucidly written for the most part-and with praiseworthy humility when the authors are unable to explain the means of production of sounds and murmurs. There are a few curious verbal lapses-as, for instance, the definition of a murmur as "the auditory perception of vibrations produced by the flow of blood". Also, for triple rhythm the authors always use the unfortunate term "gallop", which seems to come so readily to physicians' lips in the land of Paul Revere.