First account of infantile tetany is given on pp. 86-97. Clarke died before this work was published. In it he also gave a clear description of laryngismus stridulus. This disease, which consists in a sudden onset of difficult breathing, obviously originating in the windpipe, was confused by Boerhaave with asthma, and by later writers with true croup. Its anatomical cause is not yet known; but Clarke's exact clinical description (Commentaries, chap. iv.) was the first step to a precise study of the affection.