burette

Mercury is run in from a burette through the side-neck and applies pressure upon the film by gravity.

A standardized solution of ammonium molybdate is then added from a burette.

After having boiled for 3 to 4 minutes, N/4 caustic soda is added until the pink color just returns and the amount of caustic soda used is read on the burette.

The alkalimeter is merely a graduated tube—a burette—with a stopcock at the lower extremity, from which the standard acid is dropped into water in which a known weight of the substance is dissolved.

And subsequently when the burette is used, the volumes read from the scale on the burette must be corrected.