In a new book, "The New Dentistry" Dr. L. M. S. Miner, Dean of the Harvard Dental School, describes tooth decay as the most ancient of all diseases. It has been found in the so-called Rhodesian man of 125,000 years ago. Dr. Minor points out that about 100,000,000 people in this country suffer from this disease, that $45,000,000 is spent for dental care a year, and that tooth diseases are steadily increasing. "The New Dentistry," published by the Harvard University Press is to be a popular and yet authoritative treatment of recent developments in dentistry and a forecast of the future.