I wish to describe a simple and easily made manometer and safety-valve which I have found useful as an addition to the usual Forlanini apparatus which is used in the operation of artificial pneumothorax in lung tuberculosis.
This consists of a liter Erlenmyer flask having a three-holed stopper. Two glass tubes are arranged as in an ordinary wash-bottle, and through these tubes the gas is passed through warm sterile saline solution before its introduction into the pleural cavity. The third is a perpendicular tube open at both ends, by means of which the operator is enabled to read the intrapleural pressure at any moment while the gas is being introduced.
This manometer tube has an opening at a certain height above the level of the saline solution in the flask, so that if at any moment during the operation the positive pressure should rise to a dangerous height the liquid