Thistle tube

A thistle tube is a piece of laboratory glassware consisting mostly of a shaft of tube, with a Reservoir and funnel-like section at the top. Thistle tubes are typically used by chemists to add liquid to an existing system of apparatus.

The thistle tube shaft is designed to allow insertion through a small hole present in some stoppers, permitting the tube to be inserted into a flask, such as an Erlenmeyer flask.