stopcock

He is just as ignorant of a stopcock, and surely it would be difficult for him to understand the burning of the gas.

A long india-rubber tube is attached to the bottom of the jar, ending in a metallic tube, and furnished with a stopcock.

The patient seats herself on the edge of a chair over a basin, introduces the tube, and turns the stopcock.

It is best to use this form with a glass stopcock, or with an india-rubber tube and clip, after the manner of a Mohr's burette.

The standard solution must be put in a burette with a glass stopcock, as it attacks india-rubber.