The first-aid treatment of mass casualties from nerve gas relies mainly upon the use of drugs, and provision for their self-injection is recommended. Means for giving artificial respiration must also be provided, even though its large-scale use is regarded as impracticable. Prophylactic oxime (2 g. PAM chloride orally) is recommended if the situation permits. Some nerve gases are extremely rapid in action, and following exposure (or suspicion of exposure) 4 mg. of atropine and 2 g. of PAM chloride should be injected intramuscularly without delay. Preferably, atropine should be given intravenously. At the same time any clothing contaminated with liquid nerve gas should be removed and the skin cleansed thoroughly with a suitable fluid. Following this, the casualty should be watched closely for one hour. If poisoning develops despite these measures, or is already established, injection of atropine should be continued at short intervals until improvement occurs.