Gosh! I'd forgotten it was by Shaw! Isn't the Internet wonderful?
A gazogene is a soda syphon.
http://www.brucetaub.com/bjtnotes.htm#POISON
PASSION, POISON, AND PETRIFACTION OR THE FATAL GAZOGENE
by
Bruce J. Taub
Passion, Poison, and Petrifaction or the Fatal Gazogene is "A Brief Tragedy for Barns and Booths" written in 1905 by George Bernard Shaw and first presented in "The Theatre Royal" (a "tent booth" theatre) at the Theatrical Garden Party, Regent's Park, London in aid of the Actors' Orphanage Fund. An attempt on the life of Lady Magnesia Fitztollemache is thwarted by a providential sneeze and she recognizes the would-be murderer as her husband, George. Adolphus (her lover) enters and George poisons him with soda water from the gazogene. Magnesia manages to convince her husband to reveal the antidote, however, which is lime (not the fruit, but calcium oxide). They cram pieces of plaster from the ceiling into Adolphus which make him half crazy and thirsty for the remaining soda water which then causes him to effervesce. After a great commotion involving the landlord, a policeman and finally a doctor, a thunderbolt enters the room killing all three. The maid sweeps them up and retires for the night. Lady Magnesia and George then prop up Adolphus who has now completely petrified while angels sing "Bill Bailey" and the "living statue" raises his hands towards heaven.













