That a third edition of Duncan's "Diseases of Metabolism" should be called for shows the well-deserved popularity which has been won by this book. The critical chapters on carbohydrate, protein, lipid, and mineral metabolism by Soskin, White, and Cantarow make a splendid introduction. Peters has an authoritative section on water balance, as do Spies and Butt on vitamins and avitaminosis. The more clinical chapters, by Duncan and others, are authoritative and well written; the reviewer is not quite clear why diseases of the thyroid rather than of the adrenal or pituitary are included, or indeed diseases of the kidney. Well, the buyer gets just that much more for his money. The book is well printed and illustrated and is generally attractive.