Boiling tube

A boiling tube is a small cylindrical vessel used to strongly heat substances in the flame of a Bunsen burner. A boiling tube is essentially a scaled-up test tube, being about 50% larger in every aspect.

They are designed to be wide enough to allow substances to boil violently as opposed to a test tube which is too narrow for this task; boiling liquid can explode out of the end of test tubes when they are heated as there is no room for the bubbles of gas to escape independently of the surrounding liquid.

Boiling tubes are made from borosilicate glass that can withstand high temperatures.[1]

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