A device that allows for the administration of anesthetic and non-anesthetic gases to patients. If equipped with a vaporizer, the machine is also capable of delivering an anesthetic agent in the form of a vapor in conjunction with the gas or gas mixture. The vaporizer converts a liquid anesthetic into a measured amount of vapor, which is then carried to the patient by the oxygen or gas mixture. Figure 1-1shows a diagram of how the system operates. Before anesthesia can be administered, an oxygen (and/or other medical gas) supply is connected to the anesthesia machine, the vaporizer is filled with anesthetic agent, and absorber canister is filled with CO2 absorbent. The breathing bag, patient breathing circuit, and all accessory tubing and bags are then connected. The operator increases the oxygen flow rate by turning the flow meter control valve counterclockwise until the desired rate is indicated on the meter. The breathing bag gradually inflates