In neurologic surgery it frequently becomes necessary to employ an intratracheal anesthetic, particularly in work on the cerebellum and the brain stem, when a patient may have respiratory difficulty that may be relieved by the administration of plenty of pure air under slight pressure. There are many intratracheal anesthetic machines in use, some of which are used very successfully, but the general tendency has been to make them too complicated. In view of this fact, it seemed permissible to construct a machine that would be efficient yet simple and easy to manipulate. The one herein described has been constructed to conform to three principles, as follows:
1. Constant Flow of Air.
—A constant flow of air maintained and controlled so that pure air alone, or any degree of ether saturation, may be given (Fig. 2). This is accomplished by diverting the air current through valve C from E to F