Samuel Johnson once wrote: "Dictionaries are like watches, the worst is better than none, and the best cannot be expected to go quite true." Now with the publication of the most extensively revised of all the editions in the sixty-five-year history of Dorland's Illustrated Medical Dictionary, the latter half of Johnson's quotation could well be challenged. This is a dictionary which does "go quite true." Dorland's Dictionary contains a splendid chapter on the fundamentals of medical etymology by Dr. Lloyd Day, Allen Memorial Professor of Greek at the University of pennsylvania.