The hand-valve here described, which is in use in the Students' Infirmary of the University of California, has proved a convenient addition to the suction apparatus for clearing blood or other fluid from the operative field, especially in throat operations.
Negative air pressure is secured by use of the ordinary filterpump or ejector attached to a water faucet (Fig. 1). The carboy (b) is added to the system to give greater duration to the suction when it is being drawn on, air being pumped out of it for several minutes before operation begins. The mercury manometer, which hangs on the wall of the operatingroom, is not necessary, but merely a convenience, as it indicates the amount of available negative pressure. The jar (a) receives all of the aspirated fluid, and none of the parts of the system beyond this has to be cleaned.
The purpose of the hand-valve is to