A FIFTH memorandum in the Emergency Medical Services Series has been issued by the Ministry of Health entitled “Oxygen Administration—Indications, Methods and Types of Apparatus” (H.M. Stationery Office. 2d.net). The administration of oxygen is a valuable aid in the treatment of some forms of gas poisoning and lung disease, and in some surgical conditions such as shock and chest wounds. The memorandum incorporates the results of research on the subject, and is intended primarily for the guidance of medical officers in charge of hospitals. It describes the conditions for which oxygen therapy is likely to be effective, methods of oxygen administration, and the more important types of apparatus for the purpose, including a new form of nasal mask.