The Wake Up Shot

From The Heart of the Matter by Graham Greene:

For a moment Yusef seemed about to sink again into drugged sleep; then with an effort he got on an elbow… 

He shook his head, so that the white lick of hair flapped; then putting out a vague hand he stretched for the syphon…

Yusef dragged the syphon towards him across the table knocking over the bromide glass; he turned the nozzle towards his face and pulled the trigger. The soda water broke on his face and splashed all round him on the mauve silk. He gave a sigh of relief and satisfaction, like a man under a shower on a hot day.