The original Danish edition of this monograph was discussed in the editorial columns of The Journal, February 10, under the title of epidemic myalgia, or pleurodynia. The editorial summary gives references to the reports of the outbreaks of the disease in the United States. Probably the disease is more frequent than is now realized. The translation into English of Sylvest's excellent monograph will be of great help in spreading the knowledge of epidemic myalgia, also called in Danish literature Bornholm disease on account of the great many cases occurring in the Danish island Bornholm, where Sylvest, a practicing physician, made his valuable observations. Bornholm is not the place, however, where the disease was recognized first.