Gasogene
The Gasogene (or Seltzogene) was a Victorian device, a precursor of the soda siphon, for producing carbonated water.
It consisted of two linked glass globes surrounded by protective mesh. 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 gasogene features as an unexplained residential fixture at 221B Baker Street in Arthur Conan Doyle's Sherlock Holmes stories.