REFERENCE has already been made in these columns to the Second International Congress of the Scientific and Social Campaign against Cancer which was held in Brussels last autumn (NATURE. (1936), 138, 727). The text of fifty-five reports or reviews which were read at the Congress have now been published. Each report is given at length in one of the six official languages, while summaries of the reports are given in all six languages. Some of the reports, such as that of Cook, Haslewood, Hewett, Hieger, Kennaway and Mayneord on “Chemical Compounds as Carcinogenic Agents” and that of Reding on “Predisposition and Resistance to Cancer”, have good bibliographies, while others have no references. The greater part of the volume is concerned with the biology, diagnosis and therapy of cancer, and there are interesting reviews on the statistical investigation of mortality from cancer in different States and among different races.