Gasogene
Appearance
The gasogene (or seltzogene) was a late Victorian device for producing carbonated water.
It consisted of two linked glass globes surrounded by a wicker or wire protective mesh because they tended to explode. The lower contained water or other drink to be made sparkling, the upper a mixture of tartaric acid and sodium bicarbonate that reacted to produce carbon dioxide. The produced gas pushes the liquid in the lower container up a tube and out of the device.
The gasogene features as a cryptic residential fixture at 221B Baker Street in Arthur Conan Doyle's Sherlock Holmes stories.