During the First World War a sophisticated system of recovering and treating wounded soldiers was developed.Stretcher bearers were the 'first responders'. They gave first aid and carried the wounded to the Regimental Aid Post. A medical officer would then try to stabilise the wounded for onward transportation, administering morphine as necessary. Morphine was the main form of pain relief during this period and was either given orally or by injection. The hypodermic glass syringe, developed in the mid-nineteenth century, allowed the injection of a controlled dose into the patient.Before the First World War morphine and other drugs were freely available. Concerns regarding the addictive effects of morphine and other narcotics on the fighting forces led to more stringent drug controls during the First World War.