Gasogene

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. It is a siphon in that the produced gas pushes the liquid out of the device.

The gasogene features as a cryptic residential fixture at 221B Baker Street in Arthur Conan Doyle's Sherlock Holmes stories.