A VALVE TO REGULATE THE DELIVERY OF AIR AND ETHER VAPOR IN ANY PROPORTION

A valve is described for the control of ether vapor for anesthesia which regulates the mixture of ether vapor from a Woulfe bottle with air in any proportion, without changing the volume or the pressure at which the mixture is delivered. The regulation of the air stream both to and from the ether bottle controls the mixture accurately and is an essential feature of the valve. Except for experimental purposes, it is not considered profitable to determine on an arbitrary scale the tension of the ether vapor obtained, because the depth of the anesthesia should always be judged by the condition of the subject. The valve was devised for the Meltzer-Auer method of intratracheal insufflation, but it is adapted for use wherever a constant mixture of air and ether vapor is desired. Several respiration machines for supplying and interrupting the air stream, using this constant volume valve for the regulation of the ether supply, have been in use in Dr. Meltzer's laboratory for periods up to 2 years, and the simplicity and efficiency of the valve have been thoroughly tested. A description of the complete machine will be published later.