Thistle tube
Use
Continuous addition of liquid in a container, without needing to take the lid off. In addition, it works / serves as a safety system to avoid splatters caused by a sharp pressure rise during the chemical reaction.
Description
It may have many different shapes. The simplest one is a bulb-ended cylindrical tube. The most complex ones contain several intermediate buffer shaped like a sphere. Their manufacturing is always in glass.
Functioning
The flask in which the chemical reaction will take place is closed with a cap. This cap has got a perforation through which the thistle tube is inserted. The liquid for the chemical reaction is poured in the bulb and it falls little by little, reacting with the substances inside the flask. If any gases are generated in this process, the liquid in the tube serves as safety valve, avoid potentially-dangerous projections.
